Re: Tomcat performance goes down after install apr.

[杨华杰]

Well, here is the information

the platform (OS) redhat enterprise 6.4(64 bit)
- the Java JVM version used (1.7.45)
- the Tomcat version used (7.0.45)
- the APR version used (APR from redhat cd)

On Tue, Nov 11, 2014 at 5:00 PM, André Warnier  wrote:

> 杨华杰 wrote:
>
>> Tomcat performance goes down after install apr.
>>
>> I followed this doc
>> http://tomcat.apache.org/native-doc/, I think the different is I didn't
>> set sslengine setting as I don't use it. And I saw the error in
>> catilina.out, I simply ignore it as I don't use it.
>>
>> I fired 300 concurrent calls from another server and I found tomcat just
>> dead. Performance is much worse. Anything I did wrong?
>>
>
> Hi.
>
> For a question like this (and basically any other question), you should
> really communicate
> - the platform (OS) under which you are running this
> - the Java JVM version used (x.y.z)
> - the Tomcat version used (x.y.z)
> - the APR version used (x.y.z)
> otherwise, how do you want anyone to comment ?
>
> -
> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org
> For additional commands, e-mail: users-h...@tomcat.apache.org
>
>

Re: Tomcat performance goes down after install apr.

[André Warnier]

杨华杰 wrote:

Tomcat performance goes down after install apr.

I followed this doc
http://tomcat.apache.org/native-doc/, I think the different is I didn't set sslengine setting as I don't use it. And I saw the error in catilina.out, I simply ignore it as I don't use it. 



I fired 300 concurrent calls from another server and I found tomcat just dead. 
Performance is much worse. Anything I did wrong?


Hi.

For a question like this (and basically any other question), you should really 
communicate
- the platform (OS) under which you are running this
- the Java JVM version used (x.y.z)
- the Tomcat version used (x.y.z)
- the APR version used (x.y.z)
otherwise, how do you want anyone to comment ?

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Re: Tomcat performance problem

[Mark Thomas]

On 25/11/2012 00:50, Alex Moskvin wrote:
> Hi,
> 
> I am using Tomcat 7.0.30 and OpenEJB 4.5 to host high loaded app and at
> some point found with VisualVM there is a bottleneck when there is a lot of
> concurrent requests (about 400-600 req/sec). Requests and responses are
> small (usually not larger than 2kb in JSON format) - almost all CPU time is
> occupied by TaskQueue.poll() calls and general response latency becomes
> very slow.
> I tried APR/Nio connectors and different threading setting and that didn't
> help anyhow. Tuning (increasing) amount of threads in thread pools didn't
> help as well.
> Tests were conducted on Intel Core i7 3450, 8Gb RAM, 100Mb network, RHEL
> 6.3 x64.
> 
> How to interpret this relatively low request rate? What I might be doing
> wrong? What can be tuned in Tomcat to improve request handling?
> Because we expect much larger request rate processing speed on the
> mentioned hardware.
> 
> Here is a VisualVM top output:
> 
> Hot spots - method; self time [%]; self time; self time (cpu)
> 
> org.apache.tomcat.util.threads.TaskQueue.poll() 75.508965 57 668 249 ms
> (75,5%) 0,000 ms

That indicates idle threads waiting for work to do. Not an issue.

> net.spy.memcached.internal.OperationFuture.get() 14.22508 10 864 079 ms
> (14,2%) 6 798 ms
> net.spy.memcached.internal.BulkGetFuture.internalGet() 5.644 4 308 270
> ms (5,6%) 0,000 ms

This is more interesting. That looks like the application is waiting for
memCached to complete a task. I'd look into this first.

> org.apache.tomcat.util.net.NioEndpoint$Poller.run() 0.71728086 547 806 ms
> (0,7%) 530 252 ms

That is the NIO connector's Poller processing incoming connections. I'm
a little surprised to see this appearing rather than application code
but given the relatively low % I'd not focus too much time on here just yet.

Mark


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Re: Tomcat performance problem

[Tony Anecito]

Hi Alex,
 
Typically I have found the first issue is the response time of the database 
queries. Threads and sockets will start to reach a limit when this happens.
Then after that is looked at then the next issue will be understanding what is 
really possible with the system. Just going from EJB container to Tomcat on an 
I7 will take at least 5-6msec. Depending on EJB types caching at that layer and 
the Tomcat layer may be needed.
Sorry you are just starting tuning. It took me years to get to sub-millisecond 
response from Database to web service interface and to see it in my logs below 
a millisecond and then I started to see latency from network external to my 
company.
 
Good Hunting.
-Tony

--- On Sat, 11/24/12, Alex Moskvin  wrote:


From: Alex Moskvin 
Subject: Tomcat performance problem
To: users@tomcat.apache.org, users-h...@tomcat.apache.org
Date: Saturday, November 24, 2012, 5:50 PM


Hi,

I am using Tomcat 7.0.30 and OpenEJB 4.5 to host high loaded app and at
some point found with VisualVM there is a bottleneck when there is a lot of
concurrent requests (about 400-600 req/sec). Requests and responses are
small (usually not larger than 2kb in JSON format) - almost all CPU time is
occupied by TaskQueue.poll() calls and general response latency becomes
very slow.
I tried APR/Nio connectors and different threading setting and that didn't
help anyhow. Tuning (increasing) amount of threads in thread pools didn't
help as well.
Tests were conducted on Intel Core i7 3450, 8Gb RAM, 100Mb network, RHEL
6.3 x64.

How to interpret this relatively low request rate? What I might be doing
wrong? What can be tuned in Tomcat to improve request handling?
Because we expect much larger request rate processing speed on the
mentioned hardware.

Here is a VisualVM top output:

Hot spots - method; self time [%]; self time; self time (cpu)

org.apache.tomcat.util.threads.TaskQueue.poll() 75.508965 57 668 249 ms
(75,5%) 0,000 ms
net.spy.memcached.internal.OperationFuture.get() 14.22508 10 864 079 ms
(14,2%) 6 798 ms
net.spy.memcached.internal.BulkGetFuture.internalGet() 5.644 4 308 270
ms (5,6%) 0,000 ms
org.apache.tomcat.util.net.NioEndpoint$Poller.run() 0.71728086 547 806 ms
(0,7%) 530 252 ms
org.quartz.core.QuartzSchedulerThread.run() 0.69727546 532 528 ms (0,7%)
0,000 ms

Regards,
Alex

Re: Tomcat Performance Turning.

[Leon Rosenberg]

Hello Talha,

On Fri, Sep 2, 2011 at 11:34 PM, Talha Fazal  wrote:
> Q. Have you tried running directly against tomcat without apache inbetween?
> A. Yes; this resolves the performance bottleneck.

Than its pretty clear where to search, isn't it?

>
> Q. from my experience there is no need for apache in your setup 
> anyway .
> A.  :-) The reasons for having apache in front:
>A) Create a DMZ and protect Tomcat from being exposed to outside attacks;
You know that httpd does nothing but forwards each and single request
to tomcat? So you are not really protect them, you just add another
(time consuming) layer.


> B) Load balancing.
You mentioned that you have 2 httpd servers, so all the traffic to 6
(or was it eight) tomcat servers are going through the two httpds?
And how do you loadbalancer the 2 httpd servers?


Regards
Leon

>
> Thanks Leon!
>
> -Original Message-
> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
> Sent: Friday, September 02, 2011 3:19 PM
> To: Tomcat Users List
> Subject: Re: Tomcat Performance Turning.
>
> Hello Talha,
>
> On Fri, Sep 2, 2011 at 6:16 PM, Talha Fazal  wrote:
>> PLEASE SEE MY ANSWERS BELOW IN UPPER CAPS.
>>
>> ONE IMPORTANT OBSERVATION: Even though, tomcat's response time is decent, 
>> for some reason, apache is taking a lot longer to serve requests. We are 
>> using mod_jk with Tomcat using AJP1.3 protocol in the connector setting in 
>> server.xml. We plan to try mod_proxy_ajp and mod_proxy instead of mod_jk. 
>> Any thoughts here?
>
> Interesting observation. Have you tried running directly against
> tomcat without apache inbetween?
> from my experience there is no need for apache in your setup
> anyway .
>
> In the past we used both mod_jk and mod_proxy_ajp, and even
> mod_proxy_ajp is somewhat faster, the difference where never 17
> seconds.
> Your best guess would probably be to test without httpd to rule out if
> tomcat or httpd is the bottleneck.
>
> regards
> Leon
>
>>
>> Thanks,
>>
>>
>> -Original Message-
>> From: R Batchelor [mailto:rsbat...@yahoo.com]
>> Sent: Friday, September 02, 2011 10:10 AM
>> To: Tomcat Users List
>> Subject: Re: Tomcat Performance Turning.
>>
>> Have you ruled out issues with db connection pooling? NO. IN FACT, THERE ARE 
>> KNOWN DBCP CONNECTION POOLING DEADLOCK ISSUES IN TOMCAT 6.0.26 
>> [https://issues.apache.org/jira/browse/DBCP-270]. I AM LOBBYING TO UPGRADE 
>> TO TOMCAT 7.0.20 AND USE THE JDBC CONNECTION POOL INSTEAD OF DBCP CONNECTION 
>> POOL.
>>
>> You might consider setting your dbcp maxWait to 8000 or less and watch
>> for "timeout waiting for idle object" exceptions.  Also, you could
>> monitor database connections/active-users on the DB side to see if your
>> dbcp pools are max'd but all the database users/connections are idle.
>> These can be symptoms of an application mis-managing its dbcp pools.
>> I WILL DEFINITELY TRY THIS OUT. THANKS!
>>
>> 
>> From: Leon Rosenberg 
>> To: Tomcat Users List 
>> Sent: Friday, September 2, 2011 7:55 AM
>> Subject: Re: Tomcat Performance Turning.
>>
>> Hello Talha,
>>
>> well... the quickshots are through.
>> You should really create some threaddumps after each other (for
>> example with jstack) and try to find out which thread is slowing the
>> app down.
>> For starters you could try with code you changed for tomcat
>> adaptations if any. The problem seems to lie beneath the surface, so
>> you will have to start
>> performance monitoring and look into the inside.
>> However, time difference of 17 seconds must be something very very
>> obvious like a synchronized block in a valve/filter, db lock (have you
>> checked the db locks?), or an if (tomcat)
>> Thread.sleep(1000L*60*17);
>>
>> regards
>> Leon
>>
>> On Fri, Sep 2, 2011 at 4:21 PM, Talha Fazal  wrote:
>>> Hi Leon,
>>>
>>> Please see any answers in CAPS below.
>>>
>>>
>>>
>>> -Original Message-
>>> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
>>> Sent: Friday, September 02, 2011 9:06 AM
>>> To: Tomcat Users List
>>> Subject: Re: Tomcat Performance Turning.
>>>
>>> Hello Talha,
>>>
>>> seems that your tomcats are fine.
>>> Question, you mention that the tomcat do not perform, but you don't
>>> tell us how you come to this conclusion except for cpu load. ANSWER: 
>>> LOOKING INTO THE TOMCAT ACCESS LOGS, THE RESPONSE TIME (%D) IS HORRI

Re: Tomcat Performance Turning.

[Leon Rosenberg]

Hello Christopher,

On Fri, Sep 2, 2011 at 11:52 PM, Christopher Schultz
 wrote:
> -BEGIN PGP SIGNED MESSAGE-
> Hash: SHA1
>
> Leon,
>
> On 9/2/2011 4:19 PM, Leon Rosenberg wrote:
>> from my experience there is no need for apache in your
>> setup anyway .
>
> Uh, load-balancing?
Aeh... loadbalancer? There are both, soft and hardware solutions.

regards
Leon


>
> - -chris
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> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
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> 7ukAnikbIxI+y/oaskk/Zv/Y4aKPpYD9
> =Dc+M
> -END PGP SIGNATURE-
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Re: Tomcat Performance Turning.

[Igor Cicimov]

Paste the workers.properties file and the mod_jk settings here. Are you
using prefork or mpm in Apache? Have you tuned the apache settings to match
the tomcat number of threads?

Igor

On Sat, Sep 3, 2011 at 7:52 AM, Christopher Schultz <
ch...@christopherschultz.net> wrote:

> -BEGIN PGP SIGNED MESSAGE-
> Hash: SHA1
>
> Leon,
>
> On 9/2/2011 4:19 PM, Leon Rosenberg wrote:
> > from my experience there is no need for apache in your
> > setup anyway .
>
> Uh, load-balancing?
>
> - -chris
> -BEGIN PGP SIGNATURE-
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> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
>
> iEYEARECAAYFAk5hUDgACgkQ9CaO5/Lv0PBfhQCdFwEDvm37L9QTe6FBns88RKLg
> 7ukAnikbIxI+y/oaskk/Zv/Y4aKPpYD9
> =Dc+M
> -END PGP SIGNATURE-
>
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>

Re: Tomcat Performance Turning.

[Christopher Schultz]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Leon,

On 9/2/2011 4:19 PM, Leon Rosenberg wrote:
> from my experience there is no need for apache in your
> setup anyway .

Uh, load-balancing?

- -chris
-BEGIN PGP SIGNATURE-
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Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

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7ukAnikbIxI+y/oaskk/Zv/Y4aKPpYD9
=Dc+M
-END PGP SIGNATURE-

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RE: Tomcat Performance Turning.

[Talha Fazal]

Q. Have you tried running directly against tomcat without apache inbetween?
A. Yes; this resolves the performance bottleneck.

Q. from my experience there is no need for apache in your setup anyway 
.
A.  :-) The reasons for having apache in front: A) Create a DMZ and protect 
Tomcat from being exposed to outside attacks; B) Load balancing.

Thanks Leon!

-Original Message-
From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com] 
Sent: Friday, September 02, 2011 3:19 PM
To: Tomcat Users List
Subject: Re: Tomcat Performance Turning.

Hello Talha,

On Fri, Sep 2, 2011 at 6:16 PM, Talha Fazal  wrote:
> PLEASE SEE MY ANSWERS BELOW IN UPPER CAPS.
>
> ONE IMPORTANT OBSERVATION: Even though, tomcat's response time is decent, for 
> some reason, apache is taking a lot longer to serve requests. We are using 
> mod_jk with Tomcat using AJP1.3 protocol in the connector setting in 
> server.xml. We plan to try mod_proxy_ajp and mod_proxy instead of mod_jk. Any 
> thoughts here?

Interesting observation. Have you tried running directly against
tomcat without apache inbetween?
from my experience there is no need for apache in your setup
anyway .

In the past we used both mod_jk and mod_proxy_ajp, and even
mod_proxy_ajp is somewhat faster, the difference where never 17
seconds.
Your best guess would probably be to test without httpd to rule out if
tomcat or httpd is the bottleneck.

regards
Leon

>
> Thanks,
>
>
> -Original Message-
> From: R Batchelor [mailto:rsbat...@yahoo.com]
> Sent: Friday, September 02, 2011 10:10 AM
> To: Tomcat Users List
> Subject: Re: Tomcat Performance Turning.
>
> Have you ruled out issues with db connection pooling? NO. IN FACT, THERE ARE 
> KNOWN DBCP CONNECTION POOLING DEADLOCK ISSUES IN TOMCAT 6.0.26 
> [https://issues.apache.org/jira/browse/DBCP-270]. I AM LOBBYING TO UPGRADE TO 
> TOMCAT 7.0.20 AND USE THE JDBC CONNECTION POOL INSTEAD OF DBCP CONNECTION 
> POOL.
>
> You might consider setting your dbcp maxWait to 8000 or less and watch
> for "timeout waiting for idle object" exceptions.  Also, you could
> monitor database connections/active-users on the DB side to see if your
> dbcp pools are max'd but all the database users/connections are idle.
> These can be symptoms of an application mis-managing its dbcp pools.
> I WILL DEFINITELY TRY THIS OUT. THANKS!
>
> ________
> From: Leon Rosenberg 
> To: Tomcat Users List 
> Sent: Friday, September 2, 2011 7:55 AM
> Subject: Re: Tomcat Performance Turning.
>
> Hello Talha,
>
> well... the quickshots are through.
> You should really create some threaddumps after each other (for
> example with jstack) and try to find out which thread is slowing the
> app down.
> For starters you could try with code you changed for tomcat
> adaptations if any. The problem seems to lie beneath the surface, so
> you will have to start
> performance monitoring and look into the inside.
> However, time difference of 17 seconds must be something very very
> obvious like a synchronized block in a valve/filter, db lock (have you
> checked the db locks?), or an if (tomcat)
> Thread.sleep(1000L*60*17);
>
> regards
> Leon
>
> On Fri, Sep 2, 2011 at 4:21 PM, Talha Fazal  wrote:
>> Hi Leon,
>>
>> Please see any answers in CAPS below.
>>
>>
>>
>> -Original Message-
>> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
>> Sent: Friday, September 02, 2011 9:06 AM
>> To: Tomcat Users List
>> Subject: Re: Tomcat Performance Turning.
>>
>> Hello Talha,
>>
>> seems that your tomcats are fine.
>> Question, you mention that the tomcat do not perform, but you don't
>> tell us how you come to this conclusion except for cpu load. ANSWER: LOOKING 
>> INTO THE TOMCAT ACCESS LOGS, THE RESPONSE TIME (%D) IS HORRIBLE).
>> What is the difference in response times between weblogic and tomcat? 
>> ANSWER: FOR PAGES THAT WEBLOGIC SERVES IN 500 ms ON AVERAGE, TOMCAT IS 
>> TAKING 17000 ms ON AVERAGE.
>> Maybe your tomcat just perform the job MUCH faster ;-)
>> The thread dump you posted in another reply indicates that your
>> tomcats are idling.
>> Do you have manager installed? NO. With manager you could monitor active
>> connections and requests.
>> Do you have probe installed? YES, WE HAVE IT INSTALLED. A LOT OF THREADS ARE 
>> IDLING IS WHAT WE OBSERVE.
>> Finally, if you really want to profile your application, do you have
>> moskito installed? :-) (the one i initially wrote
>> -moskito.anotheria.net, therefore the shameless advertisement). :-) SURE 
>> WILL GIVE IT A TRY [TIME PERMITTING].
>>
>> In the last case I can offer you to provide suppor

Re: Tomcat Performance Turning.

[Leon Rosenberg]

Hello Talha,

On Fri, Sep 2, 2011 at 6:16 PM, Talha Fazal  wrote:
> PLEASE SEE MY ANSWERS BELOW IN UPPER CAPS.
>
> ONE IMPORTANT OBSERVATION: Even though, tomcat's response time is decent, for 
> some reason, apache is taking a lot longer to serve requests. We are using 
> mod_jk with Tomcat using AJP1.3 protocol in the connector setting in 
> server.xml. We plan to try mod_proxy_ajp and mod_proxy instead of mod_jk. Any 
> thoughts here?

Interesting observation. Have you tried running directly against
tomcat without apache inbetween?
from my experience there is no need for apache in your setup
anyway .

In the past we used both mod_jk and mod_proxy_ajp, and even
mod_proxy_ajp is somewhat faster, the difference where never 17
seconds.
Your best guess would probably be to test without httpd to rule out if
tomcat or httpd is the bottleneck.

regards
Leon

>
> Thanks,
>
>
> -Original Message-
> From: R Batchelor [mailto:rsbat...@yahoo.com]
> Sent: Friday, September 02, 2011 10:10 AM
> To: Tomcat Users List
> Subject: Re: Tomcat Performance Turning.
>
> Have you ruled out issues with db connection pooling? NO. IN FACT, THERE ARE 
> KNOWN DBCP CONNECTION POOLING DEADLOCK ISSUES IN TOMCAT 6.0.26 
> [https://issues.apache.org/jira/browse/DBCP-270]. I AM LOBBYING TO UPGRADE TO 
> TOMCAT 7.0.20 AND USE THE JDBC CONNECTION POOL INSTEAD OF DBCP CONNECTION 
> POOL.
>
> You might consider setting your dbcp maxWait to 8000 or less and watch
> for "timeout waiting for idle object" exceptions.  Also, you could
> monitor database connections/active-users on the DB side to see if your
> dbcp pools are max'd but all the database users/connections are idle.
> These can be symptoms of an application mis-managing its dbcp pools.
> I WILL DEFINITELY TRY THIS OUT. THANKS!
>
> ________
> From: Leon Rosenberg 
> To: Tomcat Users List 
> Sent: Friday, September 2, 2011 7:55 AM
> Subject: Re: Tomcat Performance Turning.
>
> Hello Talha,
>
> well... the quickshots are through.
> You should really create some threaddumps after each other (for
> example with jstack) and try to find out which thread is slowing the
> app down.
> For starters you could try with code you changed for tomcat
> adaptations if any. The problem seems to lie beneath the surface, so
> you will have to start
> performance monitoring and look into the inside.
> However, time difference of 17 seconds must be something very very
> obvious like a synchronized block in a valve/filter, db lock (have you
> checked the db locks?), or an if (tomcat)
> Thread.sleep(1000L*60*17);
>
> regards
> Leon
>
> On Fri, Sep 2, 2011 at 4:21 PM, Talha Fazal  wrote:
>> Hi Leon,
>>
>> Please see any answers in CAPS below.
>>
>>
>>
>> -Original Message-
>> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
>> Sent: Friday, September 02, 2011 9:06 AM
>> To: Tomcat Users List
>> Subject: Re: Tomcat Performance Turning.
>>
>> Hello Talha,
>>
>> seems that your tomcats are fine.
>> Question, you mention that the tomcat do not perform, but you don't
>> tell us how you come to this conclusion except for cpu load. ANSWER: LOOKING 
>> INTO THE TOMCAT ACCESS LOGS, THE RESPONSE TIME (%D) IS HORRIBLE).
>> What is the difference in response times between weblogic and tomcat? 
>> ANSWER: FOR PAGES THAT WEBLOGIC SERVES IN 500 ms ON AVERAGE, TOMCAT IS 
>> TAKING 17000 ms ON AVERAGE.
>> Maybe your tomcat just perform the job MUCH faster ;-)
>> The thread dump you posted in another reply indicates that your
>> tomcats are idling.
>> Do you have manager installed? NO. With manager you could monitor active
>> connections and requests.
>> Do you have probe installed? YES, WE HAVE IT INSTALLED. A LOT OF THREADS ARE 
>> IDLING IS WHAT WE OBSERVE.
>> Finally, if you really want to profile your application, do you have
>> moskito installed? :-) (the one i initially wrote
>> -moskito.anotheria.net, therefore the shameless advertisement). :-) SURE 
>> WILL GIVE IT A TRY [TIME PERMITTING].
>>
>> In the last case I can offer you to provide support getting it running. WILL 
>> LET YOU KNOW IF WE ARE INTERESTED. THANKS.
>>
>> regards
>> Leon
>>
>> On Fri, Sep 2, 2011 at 3:50 PM, Talha Fazal  wrote:
>>> Plz. see my answers below in UPPERCAPS.
>>>
>>> Thanks!
>>>
>>> -Original Message-
>>> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
>>> Sent: Friday, September 02, 2011 8:35 AM
>>> To: Tomcat Users List
>>> Subject: Re: Tomcat Performance Turning.
>>

RE: Tomcat Performance Turning.

[Talha Fazal]

PLEASE SEE MY ANSWERS BELOW IN UPPER CAPS.

ONE IMPORTANT OBSERVATION: Even though, tomcat's response time is decent, for 
some reason, apache is taking a lot longer to serve requests. We are using 
mod_jk with Tomcat using AJP1.3 protocol in the connector setting in 
server.xml. We plan to try mod_proxy_ajp and mod_proxy instead of mod_jk. Any 
thoughts here?

Thanks,


-Original Message-
From: R Batchelor [mailto:rsbat...@yahoo.com] 
Sent: Friday, September 02, 2011 10:10 AM
To: Tomcat Users List
Subject: Re: Tomcat Performance Turning.

Have you ruled out issues with db connection pooling? NO. IN FACT, THERE ARE 
KNOWN DBCP CONNECTION POOLING DEADLOCK ISSUES IN TOMCAT 6.0.26 
[https://issues.apache.org/jira/browse/DBCP-270]. I AM LOBBYING TO UPGRADE TO 
TOMCAT 7.0.20 AND USE THE JDBC CONNECTION POOL INSTEAD OF DBCP CONNECTION POOL.

You might consider setting your dbcp maxWait to 8000 or less and watch 
for "timeout waiting for idle object" exceptions.  Also, you could 
monitor database connections/active-users on the DB side to see if your 
dbcp pools are max'd but all the database users/connections are idle.  
These can be symptoms of an application mis-managing its dbcp pools.
I WILL DEFINITELY TRY THIS OUT. THANKS!


From: Leon Rosenberg 
To: Tomcat Users List 
Sent: Friday, September 2, 2011 7:55 AM
Subject: Re: Tomcat Performance Turning.

Hello Talha,

well... the quickshots are through.
You should really create some threaddumps after each other (for
example with jstack) and try to find out which thread is slowing the
app down.
For starters you could try with code you changed for tomcat
adaptations if any. The problem seems to lie beneath the surface, so
you will have to start
performance monitoring and look into the inside.
However, time difference of 17 seconds must be something very very
obvious like a synchronized block in a valve/filter, db lock (have you
checked the db locks?), or an if (tomcat)
Thread.sleep(1000L*60*17);

regards
Leon

On Fri, Sep 2, 2011 at 4:21 PM, Talha Fazal  wrote:
> Hi Leon,
>
> Please see any answers in CAPS below.
>
>
>
> -Original Message-
> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
> Sent: Friday, September 02, 2011 9:06 AM
> To: Tomcat Users List
> Subject: Re: Tomcat Performance Turning.
>
> Hello Talha,
>
> seems that your tomcats are fine.
> Question, you mention that the tomcat do not perform, but you don't
> tell us how you come to this conclusion except for cpu load. ANSWER: LOOKING 
> INTO THE TOMCAT ACCESS LOGS, THE RESPONSE TIME (%D) IS HORRIBLE).
> What is the difference in response times between weblogic and tomcat? ANSWER: 
> FOR PAGES THAT WEBLOGIC SERVES IN 500 ms ON AVERAGE, TOMCAT IS TAKING 17000 
> ms ON AVERAGE.
> Maybe your tomcat just perform the job MUCH faster ;-)
> The thread dump you posted in another reply indicates that your
> tomcats are idling.
> Do you have manager installed? NO. With manager you could monitor active
> connections and requests.
> Do you have probe installed? YES, WE HAVE IT INSTALLED. A LOT OF THREADS ARE 
> IDLING IS WHAT WE OBSERVE.
> Finally, if you really want to profile your application, do you have
> moskito installed? :-) (the one i initially wrote
> -moskito.anotheria.net, therefore the shameless advertisement). :-) SURE WILL 
> GIVE IT A TRY [TIME PERMITTING].
>
> In the last case I can offer you to provide support getting it running. WILL 
> LET YOU KNOW IF WE ARE INTERESTED. THANKS.
>
> regards
> Leon
>
> On Fri, Sep 2, 2011 at 3:50 PM, Talha Fazal  wrote:
>> Plz. see my answers below in UPPERCAPS.
>>
>> Thanks!
>>
>> -----Original Message-
>> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
>> Sent: Friday, September 02, 2011 8:35 AM
>> To: Tomcat Users List
>> Subject: Re: Tomcat Performance Turning.
>>
>> Hello Talha,
>>
>> from a quick glance at your post, do you have the same 30 max threads
>> limit in weblogic? YES.
>> Because sending 525 users through 2x30=60 max threads seems a little
>> bottlenecky. I FORGOT TO MENTION THAT ON EACH TOMCAT SERVER, WE ARE RUNNING 
>> 3 INSTANCES OF TOMCAT ON EACH OF OUR TOMCAT SERVERS (2 SERVERS), THUS 
>> 2*3*30=180 maxThreads. WE EVEN INCREASED THE maxThreads TO 120 FOR EACH 
>> INSTANCE (thus 120*6=720 maxThreads), AND MATCHED maxActive IN JNDI RESOURCE 
>> TO 120, BUT WE STILL DIDN'T SEE CONSIDERABLE IMPROVEMENT. THE CPU USAGE 
>> INCREASED FROM 7% to 10%.
>>
>> Which software are you using to produce the load? LOADRUNNER. Does it 
>> keepalive the connections? YES.
>>
>> regards
>> Leon
>>
>> On Fri, Sep 2, 2011 at 3:31 PM, Talha Fazal  wrote:
>>> Backgr

Re: Tomcat Performance Turning.

[R Batchelor]

Have you ruled out issues with db connection pooling?

You might consider setting your dbcp maxWait to 8000 or less and watch 
for "timeout waiting for idle object" exceptions.  Also, you could 
monitor database connections/active-users on the DB side to see if your 
dbcp pools are max'd but all the database users/connections are idle.  
These can be symptoms of an application mis-managing its dbcp pools.



From: Leon Rosenberg 
To: Tomcat Users List 
Sent: Friday, September 2, 2011 7:55 AM
Subject: Re: Tomcat Performance Turning.

Hello Talha,

well... the quickshots are through.
You should really create some threaddumps after each other (for
example with jstack) and try to find out which thread is slowing the
app down.
For starters you could try with code you changed for tomcat
adaptations if any. The problem seems to lie beneath the surface, so
you will have to start
performance monitoring and look into the inside.
However, time difference of 17 seconds must be something very very
obvious like a synchronized block in a valve/filter, db lock (have you
checked the db locks?), or an if (tomcat)
Thread.sleep(1000L*60*17);

regards
Leon

On Fri, Sep 2, 2011 at 4:21 PM, Talha Fazal  wrote:
> Hi Leon,
>
> Please see any answers in CAPS below.
>
>
>
> -Original Message-
> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
> Sent: Friday, September 02, 2011 9:06 AM
> To: Tomcat Users List
> Subject: Re: Tomcat Performance Turning.
>
> Hello Talha,
>
> seems that your tomcats are fine.
> Question, you mention that the tomcat do not perform, but you don't
> tell us how you come to this conclusion except for cpu load. ANSWER: LOOKING 
> INTO THE TOMCAT ACCESS LOGS, THE RESPONSE TIME (%D) IS HORRIBLE).
> What is the difference in response times between weblogic and tomcat? ANSWER: 
> FOR PAGES THAT WEBLOGIC SERVES IN 500 ms ON AVERAGE, TOMCAT IS TAKING 17000 
> ms ON AVERAGE.
> Maybe your tomcat just perform the job MUCH faster ;-)
> The thread dump you posted in another reply indicates that your
> tomcats are idling.
> Do you have manager installed? NO. With manager you could monitor active
> connections and requests.
> Do you have probe installed? YES, WE HAVE IT INSTALLED. A LOT OF THREADS ARE 
> IDLING IS WHAT WE OBSERVE.
> Finally, if you really want to profile your application, do you have
> moskito installed? :-) (the one i initially wrote
> -moskito.anotheria.net, therefore the shameless advertisement). :-) SURE WILL 
> GIVE IT A TRY [TIME PERMITTING].
>
> In the last case I can offer you to provide support getting it running. WILL 
> LET YOU KNOW IF WE ARE INTERESTED. THANKS.
>
> regards
> Leon
>
> On Fri, Sep 2, 2011 at 3:50 PM, Talha Fazal  wrote:
>> Plz. see my answers below in UPPERCAPS.
>>
>> Thanks!
>>
>> -Original Message-
>> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
>> Sent: Friday, September 02, 2011 8:35 AM
>> To: Tomcat Users List
>> Subject: Re: Tomcat Performance Turning.
>>
>> Hello Talha,
>>
>> from a quick glance at your post, do you have the same 30 max threads
>> limit in weblogic? YES.
>> Because sending 525 users through 2x30=60 max threads seems a little
>> bottlenecky. I FORGOT TO MENTION THAT ON EACH TOMCAT SERVER, WE ARE RUNNING 
>> 3 INSTANCES OF TOMCAT ON EACH OF OUR TOMCAT SERVERS (2 SERVERS), THUS 
>> 2*3*30=180 maxThreads. WE EVEN INCREASED THE maxThreads TO 120 FOR EACH 
>> INSTANCE (thus 120*6=720 maxThreads), AND MATCHED maxActive IN JNDI RESOURCE 
>> TO 120, BUT WE STILL DIDN'T SEE CONSIDERABLE IMPROVEMENT. THE CPU USAGE 
>> INCREASED FROM 7% to 10%.
>>
>> Which software are you using to produce the load? LOADRUNNER. Does it 
>> keepalive the connections? YES.
>>
>> regards
>> Leon
>>
>> On Fri, Sep 2, 2011 at 3:31 PM, Talha Fazal  wrote:
>>> Background:
>>>
>>> We have a moderately high traffic web application (between 8 to 21 million 
>>> hits/day) running Apache to serve static content (also to load balance and 
>>> create a DMZ) and Weblogic to serve dynamic content (Struts 1.1 based Java 
>>> web application).
>>> We are trying to replace Weblogic with Tomcat and we have ported our code 
>>> to work with Tomcat. All works well in Tomcat in the DEV, QA, and STAGING 
>>> environment as long as there is no real load.
>>>
>>> The Issue - Load Testing:
>>>
>>> In our staging environment for load testing, when we run the load test 
>>> using 525 concurrent users, the app doesn't perform at all. The CPU usage 
>>> (on Apache and Tomcat Servers) hovers betw

Re: Tomcat Performance Turning.

[Leon Rosenberg]

Hello Talha,

well... the quickshots are through.
You should really create some threaddumps after each other (for
example with jstack) and try to find out which thread is slowing the
app down.
For starters you could try with code you changed for tomcat
adaptations if any. The problem seems to lie beneath the surface, so
you will have to start
performance monitoring and look into the inside.
However, time difference of 17 seconds must be something very very
obvious like a synchronized block in a valve/filter, db lock (have you
checked the db locks?), or an if (tomcat)
Thread.sleep(1000L*60*17);

regards
Leon

On Fri, Sep 2, 2011 at 4:21 PM, Talha Fazal  wrote:
> Hi Leon,
>
> Please see any answers in CAPS below.
>
>
>
> -Original Message-
> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
> Sent: Friday, September 02, 2011 9:06 AM
> To: Tomcat Users List
> Subject: Re: Tomcat Performance Turning.
>
> Hello Talha,
>
> seems that your tomcats are fine.
> Question, you mention that the tomcat do not perform, but you don't
> tell us how you come to this conclusion except for cpu load. ANSWER: LOOKING 
> INTO THE TOMCAT ACCESS LOGS, THE RESPONSE TIME (%D) IS HORRIBLE).
> What is the difference in response times between weblogic and tomcat? ANSWER: 
> FOR PAGES THAT WEBLOGIC SERVES IN 500 ms ON AVERAGE, TOMCAT IS TAKING 17000 
> ms ON AVERAGE.
> Maybe your tomcat just perform the job MUCH faster ;-)
> The thread dump you posted in another reply indicates that your
> tomcats are idling.
> Do you have manager installed? NO. With manager you could monitor active
> connections and requests.
> Do you have probe installed? YES, WE HAVE IT INSTALLED. A LOT OF THREADS ARE 
> IDLING IS WHAT WE OBSERVE.
> Finally, if you really want to profile your application, do you have
> moskito installed? :-) (the one i initially wrote
> -moskito.anotheria.net, therefore the shameless advertisement). :-) SURE WILL 
> GIVE IT A TRY [TIME PERMITTING].
>
> In the last case I can offer you to provide support getting it running. WILL 
> LET YOU KNOW IF WE ARE INTERESTED. THANKS.
>
> regards
> Leon
>
> On Fri, Sep 2, 2011 at 3:50 PM, Talha Fazal  wrote:
>> Plz. see my answers below in UPPERCAPS.
>>
>> Thanks!
>>
>> -Original Message-
>> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
>> Sent: Friday, September 02, 2011 8:35 AM
>> To: Tomcat Users List
>> Subject: Re: Tomcat Performance Turning.
>>
>> Hello Talha,
>>
>> from a quick glance at your post, do you have the same 30 max threads
>> limit in weblogic? YES.
>> Because sending 525 users through 2x30=60 max threads seems a little
>> bottlenecky. I FORGOT TO MENTION THAT ON EACH TOMCAT SERVER, WE ARE RUNNING 
>> 3 INSTANCES OF TOMCAT ON EACH OF OUR TOMCAT SERVERS (2 SERVERS), THUS 
>> 2*3*30=180 maxThreads. WE EVEN INCREASED THE maxThreads TO 120 FOR EACH 
>> INSTANCE (thus 120*6=720 maxThreads), AND MATCHED maxActive IN JNDI RESOURCE 
>> TO 120, BUT WE STILL DIDN'T SEE CONSIDERABLE IMPROVEMENT. THE CPU USAGE 
>> INCREASED FROM 7% to 10%.
>>
>> Which software are you using to produce the load? LOADRUNNER. Does it 
>> keepalive the connections? YES.
>>
>> regards
>> Leon
>>
>> On Fri, Sep 2, 2011 at 3:31 PM, Talha Fazal  wrote:
>>> Background:
>>>
>>> We have a moderately high traffic web application (between 8 to 21 million 
>>> hits/day) running Apache to serve static content (also to load balance and 
>>> create a DMZ) and Weblogic to serve dynamic content (Struts 1.1 based Java 
>>> web application).
>>> We are trying to replace Weblogic with Tomcat and we have ported our code 
>>> to work with Tomcat. All works well in Tomcat in the DEV, QA, and STAGING 
>>> environment as long as there is no real load.
>>>
>>> The Issue - Load Testing:
>>>
>>> In our staging environment for load testing, when we run the load test 
>>> using 525 concurrent users, the app doesn't perform at all. The CPU usage 
>>> (on Apache and Tomcat Servers) hovers between 7% to 8%. The database server 
>>> CPU usage is also between 4 and 5%.
>>>
>>> Setup for Load Testing:
>>>
>>> We have setup 2 apache web servers (4 Quad Processors i.e. 16 CPUs each), 2 
>>> Tomcat (version 6.0.29) servers (4 Quad Processors i.e. 16 CPUs each). Each 
>>> server has 32 Gb ram. We are using AJP 1.3 to connect Tomcat and Apache.
>>>
>>> Mentioned below is the version information:
>>> Apache Version 2.2.14 (with mod_jk module)
>>> Tomcat: 6.0.29
>>> Databas

RE: Tomcat Performance Turning.

[Talha Fazal]

WE GENERATE REPORT ON NETWORK BACKLOG USING ADVANCED TOOLS, WHICH INDICATE 
NEGLIGIBLE NETWORK DELAY. AT ONE POINT TO TIME THIS WAS AN ISSUE. WE INCREASED 
THE BANDWIDTH FROM 45 MBPS TO 100 MBPS WHICH RESOLVED THE ISSUE.

THANKS, TALHA.

-Original Message-
From: Caldarale, Charles R [mailto:chuck.caldar...@unisys.com] 
Sent: Friday, September 02, 2011 9:16 AM
To: Tomcat Users List
Subject: RE: Tomcat Performance Turning.

> From: Talha Fazal [mailto:tfa...@credera.com] 
> Subject: RE: Tomcat Performance Turning.

> We did take a thread dump and we found a lot of threads locked. 
> "http-8014-9" daemon prio=10 tid=0x60965c00 nid=0x6c83 in 
> Object.wait() 
> at 
> org.apache.tomcat.util.net.JIoEndpoint$Worker.await(JIoEndpoint.java:458)

Often, a throughput problem is not the many, but just one that is holding all 
of the others up.  The example you cite above is simply a thread waiting for 
something to do.

Do you perhaps have a network problem, where requests are simply not getting 
delivered to httpd or Tomcat in a timely fashion?

 - Chuck


THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY 
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RE: Tomcat Performance Turning.

[Talha Fazal]

Hi Leon,

Please see any answers in CAPS below.



-Original Message-
From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com] 
Sent: Friday, September 02, 2011 9:06 AM
To: Tomcat Users List
Subject: Re: Tomcat Performance Turning.

Hello Talha,

seems that your tomcats are fine.
Question, you mention that the tomcat do not perform, but you don't
tell us how you come to this conclusion except for cpu load. ANSWER: LOOKING 
INTO THE TOMCAT ACCESS LOGS, THE RESPONSE TIME (%D) IS HORRIBLE).
What is the difference in response times between weblogic and tomcat? ANSWER: 
FOR PAGES THAT WEBLOGIC SERVES IN 500 ms ON AVERAGE, TOMCAT IS TAKING 17000 ms 
ON AVERAGE.
Maybe your tomcat just perform the job MUCH faster ;-)
The thread dump you posted in another reply indicates that your
tomcats are idling.
Do you have manager installed? NO. With manager you could monitor active
connections and requests.
Do you have probe installed? YES, WE HAVE IT INSTALLED. A LOT OF THREADS ARE 
IDLING IS WHAT WE OBSERVE.
Finally, if you really want to profile your application, do you have
moskito installed? :-) (the one i initially wrote
-moskito.anotheria.net, therefore the shameless advertisement). :-) SURE WILL 
GIVE IT A TRY [TIME PERMITTING].

In the last case I can offer you to provide support getting it running. WILL 
LET YOU KNOW IF WE ARE INTERESTED. THANKS.

regards
Leon

On Fri, Sep 2, 2011 at 3:50 PM, Talha Fazal  wrote:
> Plz. see my answers below in UPPERCAPS.
>
> Thanks!
>
> -Original Message-
> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
> Sent: Friday, September 02, 2011 8:35 AM
> To: Tomcat Users List
> Subject: Re: Tomcat Performance Turning.
>
> Hello Talha,
>
> from a quick glance at your post, do you have the same 30 max threads
> limit in weblogic? YES.
> Because sending 525 users through 2x30=60 max threads seems a little
> bottlenecky. I FORGOT TO MENTION THAT ON EACH TOMCAT SERVER, WE ARE RUNNING 3 
> INSTANCES OF TOMCAT ON EACH OF OUR TOMCAT SERVERS (2 SERVERS), THUS 
> 2*3*30=180 maxThreads. WE EVEN INCREASED THE maxThreads TO 120 FOR EACH 
> INSTANCE (thus 120*6=720 maxThreads), AND MATCHED maxActive IN JNDI RESOURCE 
> TO 120, BUT WE STILL DIDN'T SEE CONSIDERABLE IMPROVEMENT. THE CPU USAGE 
> INCREASED FROM 7% to 10%.
>
> Which software are you using to produce the load? LOADRUNNER. Does it 
> keepalive the connections? YES.
>
> regards
> Leon
>
> On Fri, Sep 2, 2011 at 3:31 PM, Talha Fazal  wrote:
>> Background:
>>
>> We have a moderately high traffic web application (between 8 to 21 million 
>> hits/day) running Apache to serve static content (also to load balance and 
>> create a DMZ) and Weblogic to serve dynamic content (Struts 1.1 based Java 
>> web application).
>> We are trying to replace Weblogic with Tomcat and we have ported our code to 
>> work with Tomcat. All works well in Tomcat in the DEV, QA, and STAGING 
>> environment as long as there is no real load.
>>
>> The Issue - Load Testing:
>>
>> In our staging environment for load testing, when we run the load test using 
>> 525 concurrent users, the app doesn't perform at all. The CPU usage (on 
>> Apache and Tomcat Servers) hovers between 7% to 8%. The database server CPU 
>> usage is also between 4 and 5%.
>>
>> Setup for Load Testing:
>>
>> We have setup 2 apache web servers (4 Quad Processors i.e. 16 CPUs each), 2 
>> Tomcat (version 6.0.29) servers (4 Quad Processors i.e. 16 CPUs each). Each 
>> server has 32 Gb ram. We are using AJP 1.3 to connect Tomcat and Apache.
>>
>> Mentioned below is the version information:
>> Apache Version 2.2.14 (with mod_jk module)
>> Tomcat: 6.0.29
>> Database: Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bits
>> Connection Pool: DBCP.
>>
>> Mentioned below are connector settings in conf/server.xml:
>>
>>  >        address="stagingTCserver01"
>>        backlog="300"
>>        connectionTimeout="6"
>>        enableLookups="false"
>>        maxPostSize="2097152"
>>        maxSpareThreads="10"
>>        maxThreads="30"
>>        minSpareThreads="5"
>>        port="8006"
>>        protocol="AJP/1.3"
>>        tcpNoDelay="true"
>>    />
>>
>> Mentioned below are the settings for JNDI resource configured in 
>> conf/context.xml:
>>
>>  >        name="jdbc/onlinedb"
>>        auth="Container"
>>        type="javax.sql.DataSource"
>>        driverClassName="oracle.jdbc.OracleDriver"
>>        url="

RE: Tomcat Performance Turning.

[Caldarale, Charles R]

> From: Talha Fazal [mailto:tfa...@credera.com] 
> Subject: RE: Tomcat Performance Turning.

> We did take a thread dump and we found a lot of threads locked. 
> "http-8014-9" daemon prio=10 tid=0x60965c00 nid=0x6c83 in 
> Object.wait() 
> at 
> org.apache.tomcat.util.net.JIoEndpoint$Worker.await(JIoEndpoint.java:458)

Often, a throughput problem is not the many, but just one that is holding all 
of the others up.  The example you cite above is simply a thread waiting for 
something to do.

Do you perhaps have a network problem, where requests are simply not getting 
delivered to httpd or Tomcat in a timely fashion?

 - Chuck


THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY 
MATERIAL and is thus for use only by the intended recipient. If you received 
this in error, please contact the sender and delete the e-mail and its 
attachments from all computers.


-
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Re: Tomcat Performance Turning.

[Leon Rosenberg]

Hello Talha,

seems that your tomcats are fine.
Question, you mention that the tomcat do not perform, but you don't
tell us how you come to this conclusion except for cpu load.
What is the difference in response times between weblogic and tomcat?
Maybe your tomcat just perform the job MUCH faster ;-)
The thread dump you posted in another reply indicates that your
tomcats are idling.
Do you have manager installed? With manager you could monitor active
connections and requests.
Do you have probe installed?
Finally, if you really want to profile your application, do you have
moskito installed? :-) (the one i initially wrote
-moskito.anotheria.net, therefore the shameless advertisement).

In the last case I can offer you to provide support getting it running.

regards
Leon

On Fri, Sep 2, 2011 at 3:50 PM, Talha Fazal  wrote:
> Plz. see my answers below in UPPERCAPS.
>
> Thanks!
>
> -Original Message-
> From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com]
> Sent: Friday, September 02, 2011 8:35 AM
> To: Tomcat Users List
> Subject: Re: Tomcat Performance Turning.
>
> Hello Talha,
>
> from a quick glance at your post, do you have the same 30 max threads
> limit in weblogic? YES.
> Because sending 525 users through 2x30=60 max threads seems a little
> bottlenecky. I FORGOT TO MENTION THAT ON EACH TOMCAT SERVER, WE ARE RUNNING 3 
> INSTANCES OF TOMCAT ON EACH OF OUR TOMCAT SERVERS (2 SERVERS), THUS 
> 2*3*30=180 maxThreads. WE EVEN INCREASED THE maxThreads TO 120 FOR EACH 
> INSTANCE (thus 120*6=720 maxThreads), AND MATCHED maxActive IN JNDI RESOURCE 
> TO 120, BUT WE STILL DIDN'T SEE CONSIDERABLE IMPROVEMENT. THE CPU USAGE 
> INCREASED FROM 7% to 10%.
>
> Which software are you using to produce the load? LOADRUNNER. Does it 
> keepalive the connections? YES.
>
> regards
> Leon
>
> On Fri, Sep 2, 2011 at 3:31 PM, Talha Fazal  wrote:
>> Background:
>>
>> We have a moderately high traffic web application (between 8 to 21 million 
>> hits/day) running Apache to serve static content (also to load balance and 
>> create a DMZ) and Weblogic to serve dynamic content (Struts 1.1 based Java 
>> web application).
>> We are trying to replace Weblogic with Tomcat and we have ported our code to 
>> work with Tomcat. All works well in Tomcat in the DEV, QA, and STAGING 
>> environment as long as there is no real load.
>>
>> The Issue - Load Testing:
>>
>> In our staging environment for load testing, when we run the load test using 
>> 525 concurrent users, the app doesn't perform at all. The CPU usage (on 
>> Apache and Tomcat Servers) hovers between 7% to 8%. The database server CPU 
>> usage is also between 4 and 5%.
>>
>> Setup for Load Testing:
>>
>> We have setup 2 apache web servers (4 Quad Processors i.e. 16 CPUs each), 2 
>> Tomcat (version 6.0.29) servers (4 Quad Processors i.e. 16 CPUs each). Each 
>> server has 32 Gb ram. We are using AJP 1.3 to connect Tomcat and Apache.
>>
>> Mentioned below is the version information:
>> Apache Version 2.2.14 (with mod_jk module)
>> Tomcat: 6.0.29
>> Database: Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bits
>> Connection Pool: DBCP.
>>
>> Mentioned below are connector settings in conf/server.xml:
>>
>>  >        address="stagingTCserver01"
>>        backlog="300"
>>        connectionTimeout="6"
>>        enableLookups="false"
>>        maxPostSize="2097152"
>>        maxSpareThreads="10"
>>        maxThreads="30"
>>        minSpareThreads="5"
>>        port="8006"
>>        protocol="AJP/1.3"
>>        tcpNoDelay="true"
>>    />
>>
>> Mentioned below are the settings for JNDI resource configured in 
>> conf/context.xml:
>>
>>  >        name="jdbc/onlinedb"
>>        auth="Container"
>>        type="javax.sql.DataSource"
>>        driverClassName="oracle.jdbc.OracleDriver"
>>        url="jdbc:oracle:thin:@192.168.12.10:1521:WEBDB"
>>        initialSize="1"
>>        maxActive="30"
>>        minIdle="1"
>>        maxIdle="5"
>>        maxWait="30"
>>        poolPreparedStatements="true"
>>        maxOpenPreparedStatements="300"
>>        validationQuery="SELECT 1 FROM BB_DUAL"
>>        testOnBorrow="true"
>>        validationInterval="1"
>>        testWhileIdle="true"
>>    />
>&g

RE: Tomcat Performance Turning.

[Talha Fazal]

Thx Charles! We did take a thread dump and we found a lot of threads locked. 
Please see a short sample below:

"http-8014-9" daemon prio=10 tid=0x60965c00 nid=0x6c83 in Object.wait() 
[0x4c688000..0x4c688c90]
   java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Object.java:485)
at 
org.apache.tomcat.util.net.JIoEndpoint$Worker.await(JIoEndpoint.java:458)
- locked <0x2aaae10403b0> (a 
org.apache.tomcat.util.net.JIoEndpoint$Worker)
at 
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:484)
at java.lang.Thread.run(Thread.java:619)

Sincerely, Talha.

-Original Message-
From: Caldarale, Charles R [mailto:chuck.caldar...@unisys.com] 
Sent: Friday, September 02, 2011 8:42 AM
To: Tomcat Users List
Subject: RE: Tomcat Performance Turning.

> From: Talha Fazal [mailto:tfa...@credera.com] 
> Subject: Tomcat Performance Turning.

> In our staging environment for load testing, when we run the load 
> test using 525 concurrent users, the app doesn't perform at all.
> The CPU usage (on Apache and Tomcat Servers) hovers between 7% to 
> 8%. The database server CPU usage is also between 4 and 5%.

Since your CPU usage is low, your threads must be waiting for something.  Take 
several thread dumps and find out what.

http://wiki.apache.org/tomcat/HowTo#How_do_I_obtain_a_thread_dump_of_my_running_webapp_.3F

(I'll guess maxThreads and data base connections; a max of 30 seems a bit low 
for 525 concurrent requests.)

> validationQuery="SELECT 1 FROM BB_DUAL"

Most DBs provide a very simple ping-like request capability; that would be 
preferable to a select.

> -Xms512m -Xmx2048m

In a server environment, one normally sets Xms and Xmx to the same value to 
avoid heap thrashing.  However, this is unrelated to your current problem.

 - Chuck


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RE: Tomcat Performance Turning.

[Talha Fazal]

Plz. see my answers below in UPPERCAPS.

Thanks!

-Original Message-
From: Leon Rosenberg [mailto:rosenberg.l...@gmail.com] 
Sent: Friday, September 02, 2011 8:35 AM
To: Tomcat Users List
Subject: Re: Tomcat Performance Turning.

Hello Talha,

from a quick glance at your post, do you have the same 30 max threads
limit in weblogic? YES.
Because sending 525 users through 2x30=60 max threads seems a little
bottlenecky. I FORGOT TO MENTION THAT ON EACH TOMCAT SERVER, WE ARE RUNNING 3 
INSTANCES OF TOMCAT ON EACH OF OUR TOMCAT SERVERS (2 SERVERS), THUS 2*3*30=180 
maxThreads. WE EVEN INCREASED THE maxThreads TO 120 FOR EACH INSTANCE (thus 
120*6=720 maxThreads), AND MATCHED maxActive IN JNDI RESOURCE TO 120, BUT WE 
STILL DIDN'T SEE CONSIDERABLE IMPROVEMENT. THE CPU USAGE INCREASED FROM 7% to 
10%.

Which software are you using to produce the load? LOADRUNNER. Does it keepalive 
the connections? YES.

regards
Leon

On Fri, Sep 2, 2011 at 3:31 PM, Talha Fazal  wrote:
> Background:
>
> We have a moderately high traffic web application (between 8 to 21 million 
> hits/day) running Apache to serve static content (also to load balance and 
> create a DMZ) and Weblogic to serve dynamic content (Struts 1.1 based Java 
> web application).
> We are trying to replace Weblogic with Tomcat and we have ported our code to 
> work with Tomcat. All works well in Tomcat in the DEV, QA, and STAGING 
> environment as long as there is no real load.
>
> The Issue - Load Testing:
>
> In our staging environment for load testing, when we run the load test using 
> 525 concurrent users, the app doesn't perform at all. The CPU usage (on 
> Apache and Tomcat Servers) hovers between 7% to 8%. The database server CPU 
> usage is also between 4 and 5%.
>
> Setup for Load Testing:
>
> We have setup 2 apache web servers (4 Quad Processors i.e. 16 CPUs each), 2 
> Tomcat (version 6.0.29) servers (4 Quad Processors i.e. 16 CPUs each). Each 
> server has 32 Gb ram. We are using AJP 1.3 to connect Tomcat and Apache.
>
> Mentioned below is the version information:
> Apache Version 2.2.14 (with mod_jk module)
> Tomcat: 6.0.29
> Database: Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bits
> Connection Pool: DBCP.
>
> Mentioned below are connector settings in conf/server.xml:
>
>          address="stagingTCserver01"
>        backlog="300"
>        connectionTimeout="6"
>        enableLookups="false"
>        maxPostSize="2097152"
>        maxSpareThreads="10"
>        maxThreads="30"
>        minSpareThreads="5"
>        port="8006"
>        protocol="AJP/1.3"
>        tcpNoDelay="true"
>    />
>
> Mentioned below are the settings for JNDI resource configured in 
> conf/context.xml:
>
>          name="jdbc/onlinedb"
>        auth="Container"
>        type="javax.sql.DataSource"
>        driverClassName="oracle.jdbc.OracleDriver"
>        url="jdbc:oracle:thin:@192.168.12.10:1521:WEBDB"
>        initialSize="1"
>        maxActive="30"
>        minIdle="1"
>        maxIdle="5"
>        maxWait="30"
>        poolPreparedStatements="true"
>        maxOpenPreparedStatements="300"
>        validationQuery="SELECT 1 FROM BB_DUAL"
>        testOnBorrow="true"
>        validationInterval="1"
>        testWhileIdle="true"
>    />
>
> JVM Parameters:
>
> -Xms512m -Xmx2048m
> -XX:PermSize=128m -XX:MaxPermSize=256m
> -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/logs/WL2TC/app/
> -verbose:gc -Xloggc:/logs/WL2TC/app/WL2TC_1-gc.log
>
> It must be noted that Weblogic setup performs very well using similar 
> settings.
>
> Garbage Collection: While the load test is running, Garbage collection works 
> just fine i.e. Young GC occurring every 2-3 minutes and takes less than half 
> a second. Full GC occurs every hour and takes a little over 2 seconds.
>
> Any tips/pointers will be greatly appreciated.
>
> Talha.
>

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RE: Tomcat Performance Turning.

[Caldarale, Charles R]

> From: Talha Fazal [mailto:tfa...@credera.com] 
> Subject: Tomcat Performance Turning.

> In our staging environment for load testing, when we run the load 
> test using 525 concurrent users, the app doesn't perform at all.
> The CPU usage (on Apache and Tomcat Servers) hovers between 7% to 
> 8%. The database server CPU usage is also between 4 and 5%.

Since your CPU usage is low, your threads must be waiting for something.  Take 
several thread dumps and find out what.

http://wiki.apache.org/tomcat/HowTo#How_do_I_obtain_a_thread_dump_of_my_running_webapp_.3F

(I'll guess maxThreads and data base connections; a max of 30 seems a bit low 
for 525 concurrent requests.)

> validationQuery="SELECT 1 FROM BB_DUAL"

Most DBs provide a very simple ping-like request capability; that would be 
preferable to a select.

> -Xms512m -Xmx2048m

In a server environment, one normally sets Xms and Xmx to the same value to 
avoid heap thrashing.  However, this is unrelated to your current problem.

 - Chuck


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Re: Tomcat Performance Turning.

[Leon Rosenberg]

Hello Talha,

from a quick glance at your post, do you have the same 30 max threads
limit in weblogic?
Because sending 525 users through 2x30=60 max threads seems a little
bottlenecky.
Which software are you using to produce the load? Does it keepalive
the connections?

regards
Leon

On Fri, Sep 2, 2011 at 3:31 PM, Talha Fazal  wrote:
> Background:
>
> We have a moderately high traffic web application (between 8 to 21 million 
> hits/day) running Apache to serve static content (also to load balance and 
> create a DMZ) and Weblogic to serve dynamic content (Struts 1.1 based Java 
> web application).
> We are trying to replace Weblogic with Tomcat and we have ported our code to 
> work with Tomcat. All works well in Tomcat in the DEV, QA, and STAGING 
> environment as long as there is no real load.
>
> The Issue - Load Testing:
>
> In our staging environment for load testing, when we run the load test using 
> 525 concurrent users, the app doesn't perform at all. The CPU usage (on 
> Apache and Tomcat Servers) hovers between 7% to 8%. The database server CPU 
> usage is also between 4 and 5%.
>
> Setup for Load Testing:
>
> We have setup 2 apache web servers (4 Quad Processors i.e. 16 CPUs each), 2 
> Tomcat (version 6.0.29) servers (4 Quad Processors i.e. 16 CPUs each). Each 
> server has 32 Gb ram. We are using AJP 1.3 to connect Tomcat and Apache.
>
> Mentioned below is the version information:
> Apache Version 2.2.14 (with mod_jk module)
> Tomcat: 6.0.29
> Database: Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bits
> Connection Pool: DBCP.
>
> Mentioned below are connector settings in conf/server.xml:
>
>          address="stagingTCserver01"
>        backlog="300"
>        connectionTimeout="6"
>        enableLookups="false"
>        maxPostSize="2097152"
>        maxSpareThreads="10"
>        maxThreads="30"
>        minSpareThreads="5"
>        port="8006"
>        protocol="AJP/1.3"
>        tcpNoDelay="true"
>    />
>
> Mentioned below are the settings for JNDI resource configured in 
> conf/context.xml:
>
>          name="jdbc/onlinedb"
>        auth="Container"
>        type="javax.sql.DataSource"
>        driverClassName="oracle.jdbc.OracleDriver"
>        url="jdbc:oracle:thin:@192.168.12.10:1521:WEBDB"
>        initialSize="1"
>        maxActive="30"
>        minIdle="1"
>        maxIdle="5"
>        maxWait="30"
>        poolPreparedStatements="true"
>        maxOpenPreparedStatements="300"
>        validationQuery="SELECT 1 FROM BB_DUAL"
>        testOnBorrow="true"
>        validationInterval="1"
>        testWhileIdle="true"
>    />
>
> JVM Parameters:
>
> -Xms512m -Xmx2048m
> -XX:PermSize=128m -XX:MaxPermSize=256m
> -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/logs/WL2TC/app/
> -verbose:gc -Xloggc:/logs/WL2TC/app/WL2TC_1-gc.log
>
> It must be noted that Weblogic setup performs very well using similar 
> settings.
>
> Garbage Collection: While the load test is running, Garbage collection works 
> just fine i.e. Young GC occurring every 2-3 minutes and takes less than half 
> a second. Full GC occurs every hour and takes a little over 2 seconds.
>
> Any tips/pointers will be greatly appreciated.
>
> Talha.
>

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Re: Tomcat performance issues...

[Christopher Schultz]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Tony,

On 6/30/2011 11:23 AM, Tony Anecito wrote:
> I suspect Tomcat might support the lib you mentioned

Tomcat does not need to support the library specifically: if a library
properly uses the Servlet and/or JSP APIs properly, it should work with
Tomcat. If it doesn't work, the problem is either in configuration (some
features are only available with certain spec versions), a bug in the
library or a bug in Tomcat.

> but the servlet spec

JSTL does not require the use of the most up-to-date servlet spec
(currently 3.0) in order to use it. Tomcat supports all versions of the
servlet spec up to that which is declared (spec 2.4 for TC5.5, spec 2.5
for TC6, and spec 3.0 for TC7).

> and what appeared to be a dead project worried me.

The project is not dead. I think it's just mature enough that there's
little development going on: everything works just fine, apparently.

- -chris
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Re: Tomcat performance issues...

[Tony Anecito]

Thanks I joined the taglib email list and am waiting for an answer. I suspect 
Tomcat might support the lib you mentioned but the servlet spec and what 
appeared to be a dead project worried me.

Regards,
-Tony



- Original Message 
From: Konstantin Kolinko 
To: Tomcat Users List 
Sent: Thu, June 30, 2011 9:19:49 AM
Subject: Re: Tomcat performance issues...

2011/6/30 Tony Anecito :
> Thanks for the link and it proved what I was concerned about and that is 
Tomcat
> 6 does not have an approved standard library for JSP's which means 7 has more
> issues with this "Standard" taglib.
>
> I could be wrong but the highest level of support is servlet 2.4 and Tomcat 6 
>is
> at 2.5.

All previous versions of specifications are supported.

The version 1.1.2 of the Standard taglib is included into the
"examples" web application and does works on all supported Tomcat
versions.

It is not included as "part" of Tomcat, because your web application
is free to use and bundle whatever libraries it wants, be that
taglibs, myfaces, etc etc.

Best regards,
Konstantin Kolinko

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Re: Tomcat performance issues...

[Konstantin Kolinko]

2011/6/30 Tony Anecito :
> Thanks for the link and it proved what I was concerned about and that is 
> Tomcat
> 6 does not have an approved standard library for JSP's which means 7 has more
> issues with this "Standard" taglib.
>
> I could be wrong but the highest level of support is servlet 2.4 and Tomcat 6 
> is
> at 2.5.

All previous versions of specifications are supported.

The version 1.1.2 of the Standard taglib is included into the
"examples" web application and does works on all supported Tomcat
versions.

It is not included as "part" of Tomcat, because your web application
is free to use and bundle whatever libraries it wants, be that
taglibs, myfaces, etc etc.

Best regards,
Konstantin Kolinko

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Re: Tomcat performance issues...

[Tony Anecito]

Thanks for the link and it proved what I was concerned about and that is Tomcat 
6 does not have an approved standard library for JSP's which means 7 has more 
issues with this "Standard" taglib.

I could be wrong but the highest level of support is servlet 2.4 and Tomcat 6 
is 
at 2.5.

Regards,
-Tony



- Original Message 
From: Tony Anecito 
To: Tomcat Users List 
Sent: Wed, June 29, 2011 5:10:33 PM
Subject: Re: Tomcat performance issues...

Thanks I did not spot the users group. I thought maybe the taglibs was a dead 
project seemed like there was no version that supported Tomcat 6.0.x.
I will continue the message thread onto that group thanks for the advice.

I am a tester but the response time was 3-4 seconds.

I have not asked the developers the specifics yet about the tag. Now I am more 
concerned the version of Taglib being used was like for version 5 of Tomcat and 
not for version 6.

Thanks All.
-Tony


 


- Original Message 
From: Konstantin Kolinko 
To: Tomcat Users List 
Sent: Wed, June 29, 2011 12:43:48 PM
Subject: Re: Tomcat performacne issues...

2011/6/29 Christopher Schultz :
> Apache taglibs /is/ JSTL from an API point of view.

To be more precise, JSTL is implemented by the "Standard" taglib there

http://tomcat.apache.org/taglibs/standard/

Note, that the Taglibs project has its separate "taglibs-user" mailing list.

Best regards,
Konstantin Kolinko

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Re: Tomcat performance issues...

[Tony Anecito]

Thanks I did not spot the users group. I thought maybe the taglibs was a dead 
project seemed like there was no version that supported Tomcat 6.0.x.
I will continue the message thread onto that group thanks for the advice.

I am a tester but the response time was 3-4 seconds.

I have not asked the developers the specifics yet about the tag. Now I am more 
concerned the version of Taglib being used was like for version 5 of Tomcat and 
not for version 6.

Thanks All.
-Tony


 


- Original Message 
From: Konstantin Kolinko 
To: Tomcat Users List 
Sent: Wed, June 29, 2011 12:43:48 PM
Subject: Re: Tomcat performacne issues...

2011/6/29 Christopher Schultz :
> Apache taglibs /is/ JSTL from an API point of view.

To be more precise, JSTL is implemented by the "Standard" taglib there

http://tomcat.apache.org/taglibs/standard/

Note, that the Taglibs project has its separate "taglibs-user" mailing list.

Best regards,
Konstantin Kolinko

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RE: Tomcat performance under low load

[Vijay Menon]

Hi Chris
Sorry about the delay in replying. I've been a bit busy with performance issues 
:)
The issue has come down to the vendor code persisting the cache as serialized 
objects to the file system and taking time to load it back, based on the 
decompiled code. The cache seems to be sufficiently tuned but for some reason, 
the file access is slow.
We haven't yet got the exact reason yet, so have to wait and see.
Vijay
From: vijay_me...@hotmail.com
To: users@tomcat.apache.org
Subject: RE: Tomcat performance under low load
Date: Sun, 17 Oct 2010 08:42:30 +1000








Thanks for the replies. Based on that, we did change the connectors to use 
executor threads. 
However, based on profiling the app, it turned out to be a code issue.
Thanks again.

From: vijay_me...@hotmail.com
To: users@tomcat.apache.org
Subject: Tomcat performance under low load
Date: Thu, 14 Oct 2010 09:35:14 +1000








Hi all
Thanks for reading this post. 
We are currently having 2 requirements that are opposites. The first 
requirement is performance under high loads and the other one is equivalent 
performance for 1 request.
Our prod env currently uses Apache with mod_jk and ajp 1.3 to Tomcat 6.0.26 and 
jdk 1.6.0_18 on solaris.
We're scaling to satisfactory loads of 250 concurrent requests serving pages in 
0.5 seconds.
The other test scenario is where the tomcat instance is kept idle and a single 
request is sent in every 90 or so seconds. In this case, the response takes 
about 8 seconds out of which about 6 seconds cannot be tracked.
As the result, what we're finding is that under high loads, it performs well 
but under very low loads, it does not.
This definitely happens in the tomcat layer as we've used the 
FastCommonAccessLogValve logger which gives the time for the request in Tomcat.
The connector properties are protocol="AJP/1.3" maxThreads="150" 
minSpareThreads="25" maxSpareThreads="75" acceptCount="100" 
connectionTimeout="2" disableUploadTimeout="true" 
useBodyEncodingForURI="true".
I was wondering whether anyone would be able to help with this issue.
Thanks in advance
VM

Re: Tomcat performance under low load

[Christopher Schultz]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Vijay,

On 10/16/2010 6:42 PM, Vijay Menon wrote:
> Thanks for the replies. Based on that, we did change the connectors
> to use executor threads. However, based on profiling the app, it
> turned out to be a code issue.

Glad you solved your problem. Can you tell us what your app was doing
that caused it to perform poorly under only low load? That seems like an
interesting situation.

- -chris
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RE: Tomcat performance under low load

[Vijay Menon]

Thanks for the replies. Based on that, we did change the connectors to use 
executor threads. 
However, based on profiling the app, it turned out to be a code issue.
Thanks again.

From: vijay_me...@hotmail.com
To: users@tomcat.apache.org
Subject: Tomcat performance under low load
Date: Thu, 14 Oct 2010 09:35:14 +1000








Hi all
Thanks for reading this post. 
We are currently having 2 requirements that are opposites. The first 
requirement is performance under high loads and the other one is equivalent 
performance for 1 request.
Our prod env currently uses Apache with mod_jk and ajp 1.3 to Tomcat 6.0.26 and 
jdk 1.6.0_18 on solaris.
We're scaling to satisfactory loads of 250 concurrent requests serving pages in 
0.5 seconds.
The other test scenario is where the tomcat instance is kept idle and a single 
request is sent in every 90 or so seconds. In this case, the response takes 
about 8 seconds out of which about 6 seconds cannot be tracked.
As the result, what we're finding is that under high loads, it performs well 
but under very low loads, it does not.
This definitely happens in the tomcat layer as we've used the 
FastCommonAccessLogValve logger which gives the time for the request in Tomcat.
The connector properties are protocol="AJP/1.3" maxThreads="150" 
minSpareThreads="25" maxSpareThreads="75" acceptCount="100" 
connectionTimeout="2" disableUploadTimeout="true" 
useBodyEncodingForURI="true".
I was wondering whether anyone would be able to help with this issue.
Thanks in advance
VM

Re: Tomcat performance under low load

[Christopher Schultz]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Vijay,

On 10/13/2010 7:35 PM, Vijay Menon wrote:
> We're scaling to satisfactory loads of 250 concurrent
> requests serving pages in 0.5 seconds.

Excellent (assuming that 0.5 seconds is acceptable to your team).

> The other test scenario is where the tomcat instance is kept idle
> and a single request is sent in every 90 or so seconds. In this case,
> the response takes about 8 seconds out of which about 6 seconds
> cannot be tracked. As the result, what we're finding is that under
> high loads, it performs well but under very low loads, it does not.

:(

> This definitely happens in the
> tomcat layer as we've used the FastCommonAccessLogValve logger which
> gives the time for the request in Tomcat.

I'd like to echo Chuck's suggestion: take Apache httpd out of the
equation and run your "load" test against Tomcat directly.

> The connector properties
> are protocol="AJP/1.3" maxThreads="150" minSpareThreads="25"
> maxSpareThreads="75" acceptCount="100" connectionTimeout="2"
> disableUploadTimeout="true" useBodyEncodingForURI="true".

If you want your server to be as efficient as possible, you should use
an  which will allow the request processing threads to be
destroyed during times of low activity. It's not really that big of a
deal, but it's worth mentioning.

A couple more questions:

1. How large are the requests you are processing? Is the usage profile
the same for "high load" versus "low load" situations -- other than the
actual frequency of requests, of course.

2. Are you using a database of any kind? If so, can you post the
configuration for that (minus any sensitive information, of course)?

90 seconds would be a very low timeout for a database connection, but
it's possible that you have a bottleneck in your application that
somehow only appears when you're nearly idle.

3. Is some other process running on the server during these low-load
times? Maybe some cron job or heavy reporting operation or something?

- -chris
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RE: Tomcat performance under low load

[Caldarale, Charles R]

> From: Vijay Menon [mailto:vijay_me...@hotmail.com] 
> Subject: Tomcat performance under low load

> The other test scenario is where the tomcat instance is kept 
> idle and a single request is sent in every 90 or so seconds.
> In this case, the response takes about 8 seconds out of which
> about 6 seconds cannot be tracked.

What do you measure if you send such requests directly to Tomcat, not via httpd?

 - Chuck


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Re: Tomcat performance tuning

[Ognjen Blagojevic]

Rujin,


I Installed tomcat 5.5.20 version in my Windows 2008 server and the java
version is Java 1.6.0.b105.We are using  2 Mbps Bandwidth Leased line.In
tomcat we hosted around 5(five) application.When the no of seesion increases
more than 1600 session the total application is slow and not able to open
the application sometime.


In order to solve your problem, you must first determine what is the 
bottleneck of your system. Is it a) network, b) RAM, c) CPU, or d) hard 
disk? Use appropriate tools to figure that out first.


I must notice that 1600 sessions is quite a large number for 2mbps link. 
Do you invalidate sessions and do you have a session timeout setting?


Some frameworks, like JSF implementations, might introduce extensive 
session creation if not used properly. Please explain when is your 
session created and when is destroyed.




1) How can I tune this application in server side for better performance in
tomcat side as well as java?


That depends on the reason for slow down. Most of the time it is not JVM 
or Tomcat's fault, but faulty webapp.


For start, I would recommend to analyze JVM memory consumption, memory 
dump, session content, and to tweak with -Xmx and -Xms parameters, if 
you didn't already do that.


Also watch for garbage collection, how often it happens and when.



2) I noticed that the current thread busy count is less but the number
session is more.What might be the problem?


Those two are not directly related. Active busy thread count is related 
to the number of *simultaneous* requests, while active sessions might 
not issue requests at all (just waiting to be invalidated upon timeout).




3)More over for a IP more sessions are opened(noticed via Lambda probe).Is
there any problem in that?


Sorry, I don't understand this question.



4)What is mean by serilizable? For my application it is showing as "No"


That means that Tomcat will be able to persist your sessions to hard 
disk in case of shutdown, and to reload them upon start up. Which means 
that if your sessions are serializable, you will be able to keep them 
across Tomcat restarts, while if they are not, they will be lost.




5)What is mean by a)Max Threads b)Min and Max spare threads c)current thread
count and current thread busy?


a. Maximum number of threads Tomcat will create to answer your clients 
request. That should be over of predicted maximum number of simultaneous 
requests (not sessions!).


b. Minimum and maximum of threads that are currently not answering any 
requests. Minimum will ensure that there is available thread when new 
request comes, and maximum will ensure that JVM does not keep too many 
threads doing nothing and eating up resources.


c1. Current number of active threads processing requests, or waiting to 
process requests.


c2. Current number of active threads processing requests.


They relate like this:

thread_busy <= thread_busy + spare_min <= thread_active <= thread_busy + 
spare_max <= max_threads



-Ognjen

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RE: tomcat performance differences between windows and linux

[Dave Siracusa]

I think you're spot on.  I suspect the default configuration may be causing 
problems.

The box is locked down, I will need to go over it with the sysadmin.

I found: 
http://www.mastertheboss.com/en/jboss-application-server/113-jboss-performance-tuning-1.html

 

Regards, 
Dave 


 

> Date: Fri, 28 May 2010 10:35:07 -0400
> From: jhubbsl...@att.net
> To: users@tomcat.apache.org
> Subject: Re: tomcat performance differences between windows and linux
> 
> On 5/28/10 10:06 AM, Christopher Schultz wrote:
> > What about network configuration? Are both servers the same "distance"
> > from you on the network?
> > 
> That's a reasonable question.
> 
> The only thing I can add - and I wish I knew more about this than I do - 
> is that Linux is configurable to a fault when it comes to process/thread 
> management and it may be that RHEL 5.5 just isn't set up to be very good 
> at this with the default kernel, kernel config, and /sys parameters. 
> Perhaps someone else has gone the rest of the way down the same road and 
> written up what they did.
> 
> You may have other things in the mix on RHEL that are superfluous, like 
> LVM2 or SELinux. It might be a more fair comparison if you don't use 
> and/or disable that stuff.
> 
> - Jeff
> 
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Re: tomcat performance differences between windows and linux

[Jeff Hubbs]

On 5/28/10 10:27 AM, Dave Siracusa wrote:

Yes both are on the same network and same distance.  If I limit it to 30 
threads their behavior is the same.
   
By this do you mean that the timing of both systems more closely match 
each other if you produce just 30 threads on each?


As far as the version, it's an embedded 5.5 runing in jboss app server.
   

I think there still ought to be a third number there...it may be important.

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Re: tomcat performance differences between windows and linux

[Jeff Hubbs]

On 5/28/10 10:06 AM, Christopher Schultz wrote:

What about network configuration? Are both servers the same "distance"
from you on the network?
   

That's a reasonable question.

The only thing I can add - and I wish I knew more about this than I do - 
is that Linux is configurable to a fault when it comes to process/thread 
management and it may be that RHEL 5.5 just isn't set up to be very good 
at this with the default kernel, kernel config, and /sys parameters.  
Perhaps someone else has gone the rest of the way down the same road and 
written up what they did.


You may have other things in the mix on RHEL that are superfluous, like 
LVM2 or SELinux.  It might be a more fair comparison if you don't use 
and/or disable that stuff.


- Jeff

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RE: tomcat performance differences between windows and linux

[Dave Siracusa]

Yes both are on the same network and same distance.  If I limit it to 30 
threads their behavior is the same.
 
As far as the version, it's an embedded 5.5 runing in jboss app server.
 
Regards, 
Dave 



 

> Date: Fri, 28 May 2010 10:06:32 -0400
> From: ch...@christopherschultz.net
> To: users@tomcat.apache.org
> Subject: Re: tomcat performance differences between windows and linux
> 
> -BEGIN PGP SIGNED MESSAGE-
> Hash: SHA1
> 
> Dave,
> 
> On 5/28/2010 8:25 AM, Dave Siracusa wrote:
> > If I run this test against a Windows hosted tomcat all threads 
> > pretty much start at the same time and end within 10-20 msec of each
> > other.
> > 
> > When I run the test against a linux hosted tomcat the first 30 or so 
> > threads are fine, the remaining pause for 1000-3000 msec and then
> > finish.
> > 
> > I have the connector settings set to:
> > 
> >  > maxThreads="250" minSpareThreads="50" maxSpareThreads="100"
> > enableLookups="false" redirectPort="8443" acceptCount="500" debug="0"
> > connectionTimeout="2"
> > disableUploadTimeout="true" />
> > 
> > I'm using the embedded tomcat in RH SOA-P 5.0.0 GA. 
> > 
> > I believe SOA-P hosts a version 5.5, I can verify.
> 
> When you do, please post the complete version number 5.5.what?
> 
> > I did have the opportunity to try it on a vanilla jboss server and
> > it behaved the same way.
> > 
> > Windows - Windows 7 64bit
> > 
> > Linux - SMP x86_64 x86_64 x86_64 GNU/Linux - Red Hat Enterprise Linux 
> > Server release 5.5 (Tikanga)
> > * Ulimit nofile is default (1024), however doesn't climb beyond 600 during 
> > testing.
> > 
> > * The linux server isn't doing much of anything when I'm testing.
> 
> What about network configuration? Are both servers the same "distance"
> from you on the network?
> 
> - -chris
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Re: tomcat performance differences between windows and linux

[Christopher Schultz]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Dave,

On 5/28/2010 8:25 AM, Dave Siracusa wrote:
> If I run this test against a Windows hosted tomcat all threads 
> pretty much start at the same time and end within 10-20 msec of each
> other.
> 
> When I run the test against a linux hosted tomcat the first 30 or so 
> threads are fine, the remaining pause for 1000-3000 msec and then
> finish.
>  
> I have the connector settings set to:
> 
> maxThreads="250" minSpareThreads="50" maxSpareThreads="100"
>enableLookups="false" redirectPort="8443" acceptCount="500" debug="0"
>connectionTimeout="2"
>disableUploadTimeout="true" />
> 
> I'm using the embedded tomcat in RH SOA-P 5.0.0 GA.  
> 
> I believe SOA-P hosts a version 5.5, I can verify.

When you do, please post the complete version number 5.5.what?

> I did have the opportunity to try it on a vanilla jboss server and
> it behaved the same way.
> 
> Windows - Windows 7 64bit
> 
> Linux - SMP x86_64 x86_64 x86_64 GNU/Linux -  Red Hat Enterprise Linux Server 
> release 5.5 (Tikanga)
>   * Ulimit nofile is default (1024), however doesn't climb beyond 600 during 
> testing.
> 
>   * The linux server isn't doing much of anything when I'm testing.

What about network configuration? Are both servers the same "distance"
from you on the network?

- -chris
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[OT] Application speed (was Re: Tomcat performance benchmark)

[Peter Crowther]

2009/12/7 André Warnier 

> On the other hand, it would be really interesting to compare the
> performance of a set of webservers 5 years ago, with the current ones, if
> the comparison is in terms of real-world application requests served.
> Granted, servers have become faster, memory and disk have become cheaper,
> bandwidth has increased, code may have been somewhat improved in the
> meantime.  But on the other hand applications have also gotten bloated in
> the meantime, so I am not quite sure that there would be that much
> difference in the end.
>
> I suspect you'd find that the application servers used similar numbers of
instructions on the common code paths, OSs varied a little but hadn't
bloated too much, and the cost/benefit trade-off of application developer
time against hardware cost was the same as ever: once the system is "fast
enough", no more optimisation is done.  If the system becomes "no longer
fast enough", another round of optimisation or hardware acquisition is
performed, depending on the expected costs of the two paths.

If you look at computers and application software as a means to an end,
rather than an end in itself, this is surely the most economically
appropriate way of constructing it?  Even though artisan and craftsman
programmers might like to pretend otherwise.

- Peter

Re: Tomcat performance benchmark

[André Warnier]

Peter Crowther wrote:

2009/12/7 Neil Aggarwal 


Here is one that is somewhat dated:
http://www.webperformanceinc.com/library/reports/ServletReport/

Good grief, that's not so much "dated" as "coming back from beyond the

grave"!  It's two major versions and a lot of performance optimisations out
of date for Tomcat, and I assume about the same for the other containers
benchmarked.

Benchmarking current performance based on that report is rather like
assuming the current Formula 1 motor racing teams are showing similar
relative performance to their placing in the 1970s.

On the other hand, it would be really interesting to compare the 
performance of a set of webservers 5 years ago, with the current ones, 
if the comparison is in terms of real-world application requests served.
Granted, servers have become faster, memory and disk have become 
cheaper, bandwidth has increased, code may have been somewhat improved 
in the meantime.  But on the other hand applications have also gotten 
bloated in the meantime, so I am not quite sure that there would be that 
much difference in the end.



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RE: Tomcat performance benchmark

[Caldarale, Charles R]

> From: peter.crowth...@googlemail.com
> [mailto:peter.crowth...@googlemail.com] On Behalf Of Peter Crowther
> Subject: Re: Tomcat performance benchmark
> 
> Benchmarking current performance based on that report is rather like
> assuming the current Formula 1 motor racing teams are showing similar
> relative performance to their placing in the 1970s.

So Matra and Tyrrell aren't doing so well now?

 - Chuck


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Re: Tomcat performance benchmark

[Peter Crowther]

2009/12/7 Neil Aggarwal 

> Here is one that is somewhat dated:
> http://www.webperformanceinc.com/library/reports/ServletReport/
>
> Good grief, that's not so much "dated" as "coming back from beyond the
grave"!  It's two major versions and a lot of performance optimisations out
of date for Tomcat, and I assume about the same for the other containers
benchmarked.

Benchmarking current performance based on that report is rather like
assuming the current Formula 1 motor racing teams are showing similar
relative performance to their placing in the 1970s.

- Peter

RE: Tomcat performance benchmark

[Neil Aggarwal]

Hello:

> I would like to know if anybody could provide me with a 
> unbiased "tomcat vs
> others" peformance benchmark

Here is one that is somewhat dated:
http://www.webperformanceinc.com/library/reports/ServletReport/

Neil

--
Neil Aggarwal, (281)846-8957, http://UnmeteredVPS.net
Host your tomcat app on a CentOS VPS for only $25/month!
Unmetered bandwidth, 7 day free trial, Google Checkout


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Re: Tomcat performance benchmark

[Mark Thomas]

Cae Fernandes wrote:
> Hello guys,
> 
> I would like to know if anybody could provide me with a unbiased "tomcat vs
> others" peformance benchmark with full tests and full system specs
> (hardware, os, etc).
> 
> I'm interested in concurrent amount of users, hardware load and specs.
> I've been designing a new system that may need to sustaint a heavy amount of
> users and I need to know what to expect.
> 
> Any help is apreciated.

Performance will be 98% your app, 2% the container. If you get to the
point where the container is the major differentiating factor in
performance then either a) you have the container configured badly or b)
 you are close to getting as much performance as you can out of one
instance of your app and you'd be better off looking at options for scaling.

Some related observations:
- Benchmarks are pretty meaningless. You can construct a benchmark to
show pretty much whatever you want. For example, I've seen benchmarks
that 'prove' that each of the BIO, NIO and APR/native connector gives
the 'best' performance.

- The only benchmark that matters is how your app performs

- A good profiler is your friend. I use YourKit (because they give open
source committers free copies)

Mark




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RE: Tomcat Performance

[Caldarale, Charles R]

> From: Peng Tuck Kwok [mailto:[EMAIL PROTECTED]
> Subject: Re: Tomcat Performance
>
> David, was replying to Charles's earlier email on that.
> I thought I read it right first in the email and assumed
> Charles was correct in that.

Assuming you're referring to me, I have not commented on this thread prior to 
this message.  (There's insufficient real information to comment about.)

 - Chuck


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Re: Tomcat Performance

[Peng Tuck Kwok]

David, was replying to Charles's earlier email on that.
I thought I read it right first in the email and assumed Charles was correct
in that.
Hazards of reading mail on the go :P


On Wed, Nov 12, 2008 at 9:26 PM, David kerber <[EMAIL PROTECTED]> wrote:

> Peng Tuck Kwok wrote:
>
>> Probably the reason why he's seeing one instance of tomcat moving quicker
>> than 2 instances is the fact that there is some form of contention for
>> resources on that single machine assuming that the 2 instances are
>> configured identically in every aspect (other than ports).
>>
>>
> You mis-read it.  He's seeing twice the performance from two instances than
> he is one single one, which shouldn't be if the one is properly configured,
> (with the exception noted below).
>
> D
>
>
>  The idea is not to give you a 0-60 mph capability with 2 tomcats on a
>> single
>> box (partition) but to give you better throughput. As I understand it,
>> when
>> you start getting more load, you'd be able to handle the requests in a
>> linear fashion (again assuming you've sized the 2 or more instances
>> correctly).
>>
>> *>I would rarely recommend that a client run parallel app servers on the
>>
>>
>>> same machine for the same application for any purposes other than being
>>> able to switch between versions of the same application (say, for
>>> zero-downtime upgrade strategy).
>>>
>>>
>> *I wouldn't recommend anyone do that just to switch versions for a zero
>> downtime upgrade strategy as well. Some sort of DR would be better for
>> this
>> ? Down production and switch to DR then when upgrades are complete just
>> reverse what has been done.
>>
>> *>Since the OP didn't say that's what his
>>
>>
>>> requirements were, there doesn't seem to be a compelling reason to use
>>> this strategy.
>>>
>>>
>> *You're right, until we really know what his requirements/KPI's on that
>> are
>> then most of this is largely academic.
>>
>> Nishi, the link to the redbook is here
>> http://www.redbooks.ibm.com/abstracts/sg246392.html?Open .
>> It's websphere specific, but there's still lot of things you can pick up
>> on
>> and probably apply.
>>
>> On Wed, Nov 12, 2008 at 5:15 AM, Christopher Schultz <
>> [EMAIL PROTECTED]> wrote:
>>
>>
>>
>>> -BEGIN PGP SIGNED MESSAGE-
>>> Hash: SHA1
>>>
>>> Pengtuck,
>>>
>>> [EMAIL PROTECTED] wrote:
>>>
>>>
 So let me get this straight. You are reluctant to accept a
 configuration which gives you improved throughput ? :P


>>> No, the OP is unwilling to use a configuration that doesn't make any
>>> sense: one single Tomcat should outperform two Tomcats on the same
>>> physical server (unless you are talking about a 32-bit JVM that needs a
>>> lot of memory).
>>>
>>>
>>>
 Anyway, this is not an unusual approach, from what I understand this
 simply makes full use of the resources available on that machine. Not
 uncommon in real world to see app servers like websphere being
 configured in that manner.


>>> I would rarely recommend that a client run parallel app servers on the
>>> same machine for the same application for any purposes other than being
>>> able to switch between versions of the same application (say, for
>>> zero-downtime upgrade strategy). Since the OP didn't say that's what his
>>> requirements were, there doesn't seem to be a compelling reason to use
>>> this strategy.
>>>
>>> - -chris
>>>
>>>
>>
>
>
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Re: Tomcat Performance

[Christopher Schultz]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Leon,

Leon Rosenberg wrote:
> On Wed, Nov 12, 2008 at 2:26 PM, David kerber <[EMAIL PROTECTED]> wrote:
>> Peng Tuck Kwok wrote:
>>> Probably the reason why he's seeing one instance of tomcat moving quicker
>>> than 2 instances is the fact that there is some form of contention for
>>> resources on that single machine assuming that the 2 instances are
>>> configured identically in every aspect (other than ports).
>>>
>> You mis-read it.  He's seeing twice the performance from two instances than
>> he is one single one, which shouldn't be if the one is properly configured,
> 
> Or if the application has synchronization/blocking issues.

Yup: like a small db connection pool in a db-heavy application.

- -chris
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Re: Tomcat Performance

[Leon Rosenberg]

On Wed, Nov 12, 2008 at 2:26 PM, David kerber <[EMAIL PROTECTED]> wrote:
> Peng Tuck Kwok wrote:
>>
>> Probably the reason why he's seeing one instance of tomcat moving quicker
>> than 2 instances is the fact that there is some form of contention for
>> resources on that single machine assuming that the 2 instances are
>> configured identically in every aspect (other than ports).
>>
>
> You mis-read it.  He's seeing twice the performance from two instances than
> he is one single one, which shouldn't be if the one is properly configured,

Or if the application has synchronization/blocking issues.
Leon

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Re: Tomcat Performance

[David kerber]

Peng Tuck Kwok wrote:

Probably the reason why he's seeing one instance of tomcat moving quicker
than 2 instances is the fact that there is some form of contention for
resources on that single machine assuming that the 2 instances are
configured identically in every aspect (other than ports).
  
You mis-read it.  He's seeing twice the performance from two instances 
than he is one single one, which shouldn't be if the one is properly 
configured, (with the exception noted below).


D


The idea is not to give you a 0-60 mph capability with 2 tomcats on a single
box (partition) but to give you better throughput. As I understand it, when
you start getting more load, you'd be able to handle the requests in a
linear fashion (again assuming you've sized the 2 or more instances
correctly).

*>I would rarely recommend that a client run parallel app servers on the
  

same machine for the same application for any purposes other than being
able to switch between versions of the same application (say, for
zero-downtime upgrade strategy).


*I wouldn't recommend anyone do that just to switch versions for a zero
downtime upgrade strategy as well. Some sort of DR would be better for this
? Down production and switch to DR then when upgrades are complete just
reverse what has been done.

*>Since the OP didn't say that's what his
  

requirements were, there doesn't seem to be a compelling reason to use
this strategy.


*You're right, until we really know what his requirements/KPI's on that are
then most of this is largely academic.

Nishi, the link to the redbook is here
http://www.redbooks.ibm.com/abstracts/sg246392.html?Open .
It's websphere specific, but there's still lot of things you can pick up on
and probably apply.

On Wed, Nov 12, 2008 at 5:15 AM, Christopher Schultz <
[EMAIL PROTECTED]> wrote:

  

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Pengtuck,

[EMAIL PROTECTED] wrote:


So let me get this straight. You are reluctant to accept a
configuration which gives you improved throughput ? :P
  

No, the OP is unwilling to use a configuration that doesn't make any
sense: one single Tomcat should outperform two Tomcats on the same
physical server (unless you are talking about a 32-bit JVM that needs a
lot of memory).



Anyway, this is not an unusual approach, from what I understand this
simply makes full use of the resources available on that machine. Not
uncommon in real world to see app servers like websphere being
configured in that manner.
  

I would rarely recommend that a client run parallel app servers on the
same machine for the same application for any purposes other than being
able to switch between versions of the same application (say, for
zero-downtime upgrade strategy). Since the OP didn't say that's what his
requirements were, there doesn't seem to be a compelling reason to use
this strategy.

- -chris





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Re: Tomcat Performance

[Peng Tuck Kwok]

Probably the reason why he's seeing one instance of tomcat moving quicker
than 2 instances is the fact that there is some form of contention for
resources on that single machine assuming that the 2 instances are
configured identically in every aspect (other than ports).

The idea is not to give you a 0-60 mph capability with 2 tomcats on a single
box (partition) but to give you better throughput. As I understand it, when
you start getting more load, you'd be able to handle the requests in a
linear fashion (again assuming you've sized the 2 or more instances
correctly).

*>I would rarely recommend that a client run parallel app servers on the
>same machine for the same application for any purposes other than being
>able to switch between versions of the same application (say, for
>zero-downtime upgrade strategy).
*I wouldn't recommend anyone do that just to switch versions for a zero
downtime upgrade strategy as well. Some sort of DR would be better for this
? Down production and switch to DR then when upgrades are complete just
reverse what has been done.

*>Since the OP didn't say that's what his
>requirements were, there doesn't seem to be a compelling reason to use
>this strategy.
*You're right, until we really know what his requirements/KPI's on that are
then most of this is largely academic.

Nishi, the link to the redbook is here
http://www.redbooks.ibm.com/abstracts/sg246392.html?Open .
It's websphere specific, but there's still lot of things you can pick up on
and probably apply.

On Wed, Nov 12, 2008 at 5:15 AM, Christopher Schultz <
[EMAIL PROTECTED]> wrote:

> -BEGIN PGP SIGNED MESSAGE-
> Hash: SHA1
>
> Pengtuck,
>
> [EMAIL PROTECTED] wrote:
> > So let me get this straight. You are reluctant to accept a
> > configuration which gives you improved throughput ? :P
>
> No, the OP is unwilling to use a configuration that doesn't make any
> sense: one single Tomcat should outperform two Tomcats on the same
> physical server (unless you are talking about a 32-bit JVM that needs a
> lot of memory).
>
> > Anyway, this is not an unusual approach, from what I understand this
> > simply makes full use of the resources available on that machine. Not
> > uncommon in real world to see app servers like websphere being
> > configured in that manner.
>
> I would rarely recommend that a client run parallel app servers on the
> same machine for the same application for any purposes other than being
> able to switch between versions of the same application (say, for
> zero-downtime upgrade strategy). Since the OP didn't say that's what his
> requirements were, there doesn't seem to be a compelling reason to use
> this strategy.
>
> - -chris
>
> -BEGIN PGP SIGNATURE-
> Version: GnuPG v1.4.9 (MingW32)
> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
>
> iEYEARECAAYFAkkZ9fwACgkQ9CaO5/Lv0PCmmgCgsIDI3iuM/UZxuIeeeYxG20Sa
> f9YAoLBuum66IMTuSly3Q8kXQN8LaYz1
> =7sA/
> -END PGP SIGNATURE-
>
> -
> To start a new topic, e-mail: users@tomcat.apache.org
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>
>

Re: Tomcat Performance

[Christopher Schultz]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Pengtuck,

[EMAIL PROTECTED] wrote:
> So let me get this straight. You are reluctant to accept a
> configuration which gives you improved throughput ? :P

No, the OP is unwilling to use a configuration that doesn't make any
sense: one single Tomcat should outperform two Tomcats on the same
physical server (unless you are talking about a 32-bit JVM that needs a
lot of memory).

> Anyway, this is not an unusual approach, from what I understand this
> simply makes full use of the resources available on that machine. Not
> uncommon in real world to see app servers like websphere being
> configured in that manner.

I would rarely recommend that a client run parallel app servers on the
same machine for the same application for any purposes other than being
able to switch between versions of the same application (say, for
zero-downtime upgrade strategy). Since the OP didn't say that's what his
requirements were, there doesn't seem to be a compelling reason to use
this strategy.

- -chris

-BEGIN PGP SIGNATURE-
Version: GnuPG v1.4.9 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAkkZ9fwACgkQ9CaO5/Lv0PCmmgCgsIDI3iuM/UZxuIeeeYxG20Sa
f9YAoLBuum66IMTuSly3Q8kXQN8LaYz1
=7sA/
-END PGP SIGNATURE-

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RE: Tomcat Performance

[pengtuck]

So let me get this straight. You are reluctant to accept a configuration which 
gives you improved throughput ? :P

Anyway, this is not an unusual approach, from what I understand this simply 
makes full use of the resources available on that machine. Not uncommon in real 
world to see app servers like websphere being configured in that manner. 

I'd link you a redbook from IBM on this but it escapes my memory at this point 
in time. It might help you understand a bit more than I can explain here :D


-Original Message-
From: Nishi Kant
Sent:  10/11/2008 14:26:21
To: users@tomcat.apache.org
Subject:  Tomcat Performance

Hi All,

 

I'm trying to optimize the performance of my server, which is deployed
in a cluster environment using Apache Load balancer and Tomcat
container. mod_jk is used to communicate between load balancer and
tomcat container.  Apache is configured to use worker MPM mode.  I have
done various tests to find optimized tomcat, apache and Linux
configuration for my application. Following are the machines I'm using
for this load test.

 

Machines configurations



Apache Load balancer::  2.8 GHz Dual Core , 4GB RAM

Tomcat ::  2.66 GHz 2 CUP, Dual Core, 6 GB RAM 

 

 

There is an interesting observation when I alter my configuration to run
multiple tomcat instances on same machine. My throughput increases to 2
times the original throughput if I run 2 instance of tomcat instead of
single tomcat instance. I'm trying to understand this behavior as I'm
not very keen in running multiple tomcat instances on same machines. 

 

Thanks,

Nishi

 

 



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Re: Tomcat Performance

[Pavel Savara]

May be your tomcat is configured to server only limited number of
clients so it doesn't use all hardware power when you deploy two tomcats
you can serve twice as much clients. 

I would say tune tomcat configuration to accept more clients
connections.

Palko

On Mon, 2008-11-10 at 11:56 +0530, Nishi Kant wrote:
> Hi All,
> 
>  
> 
> I'm trying to optimize the performance of my server, which is deployed
> in a cluster environment using Apache Load balancer and Tomcat
> container. mod_jk is used to communicate between load balancer and
> tomcat container.  Apache is configured to use worker MPM mode.  I have
> done various tests to find optimized tomcat, apache and Linux
> configuration for my application. Following are the machines I'm using
> for this load test.
> 
>  
> 
> Machines configurations
> 
> 
> 
> Apache Load balancer::  2.8 GHz Dual Core , 4GB RAM
> 
> Tomcat ::  2.66 GHz 2 CUP, Dual Core, 6 GB RAM 
> 
>  
> 
> 
> 
> There is an interesting observation when I alter my configuration to run
> multiple tomcat instances on same machine. My throughput increases to 2
> times the original throughput if I run 2 instance of tomcat instead of
> single tomcat instance. I'm trying to understand this behavior as I'm
> not very keen in running multiple tomcat instances on same machines. 
> 
>  
> 
> Thanks,
> 
> Nishi
> 
>  
> 
> 
> 

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RE: Tomcat Performance

[Nishi Kant]

Hi Ronald,
 
Thanks for the response. 
With in the server, there is not much of a locking issues. Just to give
you more insight, server is like a proxy for some of the request. All
such request are delegated to an external server which may or may HTTP
protocol to handle the request. 
 
Thanks,
Nishi




From: Ronald Klop [mailto:[EMAIL PROTECTED] 
Sent: Monday, November 10, 2008 2:54 PM
To: Tomcat Users List
Cc: Nishi Kant
Subject: Re: Tomcat Performance


2 Instances don't compete for locking between threads. So possibly your
application depends a lot on locking?

Ronald.



Op maandag, 10 november 2008 om 7:26 uur schreef Tomcat Users List
:

Subject: Tomcat Performance  Date: Mon Nov 10 07:26:21 CET 2008 
From: Nishi Kant <[EMAIL PROTECTED]>
Hi All,

 

I'm trying to optimize the performance of my server, which is
deployed
in a cluster environment using Apache Load balancer and Tomcat
container. mod_jk is used to communicate between load balancer
and
tomcat container.  Apache is configured to use worker MPM mode.
I have
done various tests to find optimized tomcat, apache and Linux
configuration for my application. Following are the machines I'm
using
for this load test.

 

Machines configurations



Apache Load balancer::  2.8 GHz Dual Core , 4GB RAM

Tomcat ::  2.66 GHz 2 CUP, Dual Core, 6 GB
RAM 

 

 

There is an interesting observation when I alter my
configuration to run
multiple tomcat instances on same machine. My throughput
increases to 2
times the original throughput if I run 2 instance of tomcat
instead of
single tomcat instance. I'm trying to understand this behavior
as I'm
not very keen in running multiple tomcat instances on same
machines. 

 

Thanks,

Nishi

 

 

 

Re: Tomcat Performance

[Ronald Klop]

2 Instances don't compete for locking between threads. So possibly your 
application depends a lot on locking?

Ronald.


Op maandag, 10 november 2008 om 7:26 uur schreef Tomcat Users List 
:


Subject: Tomcat Performance
Date: Mon Nov 10 07:26:21 CET 2008
From: Nishi Kant <[EMAIL PROTECTED]>
Hi All,

 


I'm trying to optimize the performance of my server, which is deployed
in a cluster environment using Apache Load balancer and Tomcat
container. mod_jk is used to communicate between load balancer and
tomcat container.  Apache is configured to use worker MPM mode.  I have
done various tests to find optimized tomcat, apache and Linux
configuration for my application. Following are the machines I'm using
for this load test.

 


Machines configurations



Apache Load balancer::  2.8 GHz Dual Core , 4GB RAM

Tomcat ::  2.66 GHz 2 CUP, Dual Core, 6 GB RAM 

 

 


There is an interesting observation when I alter my configuration to run
multiple tomcat instances on same machine. My throughput increases to 2
times the original throughput if I run 2 instance of tomcat instead of
single tomcat instance. I'm trying to understand this behavior as I'm
not very keen in running multiple tomcat instances on same machines. 

 


Thanks,

Nishi

 

 

 

Re: tomcat performance issue.

[Jim Cox]

Are you maxing out your database connection pool?

On Wed, Jun 4, 2008 at 1:29 PM, Zufeng Huang <[EMAIL PROTECTED]> wrote:

>  proxool:
>  9
>20
>450
>100
>

RE: Tomcat performance over VMWare

[Karim Zaki]

Hi Gabe,

I allocated 2 processors to the VM.

Regards,
Karim


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Re: Tomcat performance over VMWare

[Gabe Wong]

Karim Zaki wrote:

Hi all,

I'm experiencing poor performance with Tomcat 5.0.28 running on a Windows 2000 Server VM 
(Windows Server 2003 R2 host, VMWare Server 1.0.4). Tomcat takes up around 50% of the CPU 
and the "System" process takes up the other 50% when making requests that 
return relatively quickly on a physical server. The VM has 2.5GB of RAM assigned to it, 
and the host is a quad processor machine.

Is anyone familiar with any known performance issues with Tomcat on VMWare? Any 
recommendations?

Regards,
Karim

  

Karim,

How many processors were allocated to the VM (VMWare)?


--
Regards

Gabe Wong
NGASI AppServer Manager
JAVA AUTOMATION and SaaS Enablement
http://www.ngasi.com
NEW! 8.0 - Centrally manage multiple physical servers


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Re: Tomcat Performance

[David Brown]

Hello Peter, Wow! this is good stuff: exactly what I needed. I feel sorry for 
the client when they see that first baseline! Thank you! David.

Peter Lin wrote ..
> from past experience, it's much better to use hardware load balancing. At a
> previous job, we had any where from 12-24 servers load balanced behind a
> cisco local director.
> 
> Any load balancing router today can do the job, it doesn't have to be
> cisco.  What I did in the past was to take production logs and run them in
> jmeter against a cluster of tomcat servers. All the servers were behind the
> load balancer.
> 
> After the test was run, we collected the logs to make sure the load was
> distributed evenly and we generated reports. From those reports, we compared
> the results of the new system against the system we were replacing.
> 
> That established the baseline performance for untuned tomcat. I then spent a
> week going through 10 different jvm settings and running a full set of
> benchmarks on each. At the end I looked at what concurrent loads the entire
> system needed to support and chose the settings that match those needs. In
> my test suite, I varied the number of concurrent connections, think time
> between requests, ramp up time and a mix of requests.
> 
> the key to tuning the system correctly is understanding exactly what kind of
> traffic you expect. of course that isn't always possible, so you might have
> to take a guess.
> 
> peter
> 
> On 1/30/08, David Brown <[EMAIL PROTECTED]> wrote:
> >
> > Hello Andrew, reading your email, Alan's email and the Mladen email piqued
> > my interest because I am currently working on a gig to improve the
> > performance and monitoring of two Tomcat instances supporting 3 web
> > applications and one web service. I am inclined to agree with Alan. And, did
> > you read the ML replies to the Xmx and Xms Subject line emails? I must agree
> > with the ML contributors that answered the email named in the previous
> > sentence: baseline test, apply Eden parameters to the JVM then monitor the
> > results of the load testing. Once you have all your monitoring results
> > including logs the next step is to create a new metric by comparing the
> > newly acquired data to your initial baseline test. There are very good
> > points made on both sides but I have to believe that Tomcat tuning a priori
> > is like trying to predict the weather. In my gig there are too many unknowns
> > to resolve:
> > (1) this is a legacy system which means differing verions of JDKs, Tomcat
> > instances, web apps or web services built with framework versions no longer
> > supported e.g. AXIS 1.3.
> > (2) Commercial vendors that have taken FOSS and re-packaged it as
> > proprietary software and as a result there is no direct support from the
> > vendors for: SLA source code or updated binaries that were written in this
> > century.
> > (3) I know my client wants everything upgraded and migrated if possible
> > when in reality I will have to improve the monitoring and performance issues
> > with the current servlet containers, web services and network topology as it
> > stands now.
> >
> > I know the rest of the world is moving away from clustering (horizontal
> > scaling) and more toward virtualization (vertical scaling). In my case I
> > will have to settle for horizontal scaling and the Tomcat software load
> > balancing. I welcome anyone wanting to expound on Tomcat load balancing:
> > say, a comparison between Tomcat JK connector load balancing and using an
> > appliance like Big IP.
> >
> > Like you Andrew I would cheer a  solution if it existed: just
> > dump in the number of nodes, instances, network(s), applications, web
> > services, bandwidth and client users and viola! out comes the network
> > diagram with annotations. Discussion, suggestions, advice, solutions, rants
> > and raves welcomed.
> >
> > Andrew Hole wrote ..
> > > Hello
> > >
> > > I read an interesting document from Mladen Turk (with whom I want to
> > speak
> > > directly, but I don't know direct contact) that there is a formula to
> > > calculate the number of concurrent request:
> > > http://people.apache.org/~mturk/docs/article/ftwai.html
> > >
> > > Calculating Load
> > >
> > > When determining the number of Tomcat servers that you will need to
> > satisfy
> > > the client load, the first and major task is determining the Average
> > > Application Response Time (hereafter AART). As said before, to satisfy
> > the
> > > user experience the application has to respond within half of second.
> > The
> > > content received by the client browser usually triggers couple of
> > physical
> > > requests to the Web server (e.g. images). The web page usually consists
> > of
> > > html and image data, so client issues a series of requests, and the time
> > > that all this gets processed and delivered is called AART. To get most
> > out
> > > of Tomcat you should limit the number of concurrent requests to 200 per
> > CPU.
> > >
> > > So we can come with

Re: Tomcat Performance

[Peter Lin]

yes, most hardware load balancer handle sticky sessions. this was back in
2001-2002. I don't know which model number it was, but it was part of
cisco's local director line of routers.

peter

On Jan 31, 2008 3:46 AM, andrey.morskoy <[EMAIL PROTECTED]>
wrote:

> About cisco: Peter Lin, what was the model in your case?
> Was it able to replicate sessions (sticky session maybe ) ?
>
> Peter Lin wrote:
> > from past experience, it's much better to use hardware load balancing.
> At a
> > previous job, we had any where from 12-24 servers load balanced behind a
> > cisco local director.
> >
> > Any load balancing router today can do the job, it doesn't have to be
> > cisco.  What I did in the past was to take production logs and run them
> in
> > jmeter against a cluster of tomcat servers. All the servers were behind
> the
> > load balancer.
> >
> > After the test was run, we collected the logs to make sure the load was
> > distributed evenly and we generated reports. From those reports, we
> compared
> > the results of the new system against the system we were replacing.
> >
> > That established the baseline performance for untuned tomcat. I then
> spent a
> > week going through 10 different jvm settings and running a full set of
> > benchmarks on each. At the end I looked at what concurrent loads the
> entire
> > system needed to support and chose the settings that match those needs.
> In
> > my test suite, I varied the number of concurrent connections, think time
> > between requests, ramp up time and a mix of requests.
> >
> > the key to tuning the system correctly is understanding exactly what
> kind of
> > traffic you expect. of course that isn't always possible, so you might
> have
> > to take a guess.
> >
> > peter
> >
> > On 1/30/08, David Brown <[EMAIL PROTECTED]> wrote:
> >
> >> Hello Andrew, reading your email, Alan's email and the Mladen email
> piqued
> >> my interest because I am currently working on a gig to improve the
> >> performance and monitoring of two Tomcat instances supporting 3 web
> >> applications and one web service. I am inclined to agree with Alan.
> And, did
> >> you read the ML replies to the Xmx and Xms Subject line emails? I must
> agree
> >> with the ML contributors that answered the email named in the previous
> >> sentence: baseline test, apply Eden parameters to the JVM then monitor
> the
> >> results of the load testing. Once you have all your monitoring results
> >> including logs the next step is to create a new metric by comparing the
> >> newly acquired data to your initial baseline test. There are very good
> >> points made on both sides but I have to believe that Tomcat tuning a
> priori
> >> is like trying to predict the weather. In my gig there are too many
> unknowns
> >> to resolve:
> >> (1) this is a legacy system which means differing verions of JDKs,
> Tomcat
> >> instances, web apps or web services built with framework versions no
> longer
> >> supported e.g. AXIS 1.3.
> >> (2) Commercial vendors that have taken FOSS and re-packaged it as
> >> proprietary software and as a result there is no direct support from
> the
> >> vendors for: SLA source code or updated binaries that were written in
> this
> >> century.
> >> (3) I know my client wants everything upgraded and migrated if possible
> >> when in reality I will have to improve the monitoring and performance
> issues
> >> with the current servlet containers, web services and network topology
> as it
> >> stands now.
> >>
> >> I know the rest of the world is moving away from clustering (horizontal
> >> scaling) and more toward virtualization (vertical scaling). In my case
> I
> >> will have to settle for horizontal scaling and the Tomcat software load
> >> balancing. I welcome anyone wanting to expound on Tomcat load
> balancing:
> >> say, a comparison between Tomcat JK connector load balancing and using
> an
> >> appliance like Big IP.
> >>
> >> Like you Andrew I would cheer a  solution if it existed:
> just
> >> dump in the number of nodes, instances, network(s), applications, web
> >> services, bandwidth and client users and viola! out comes the network
> >> diagram with annotations. Discussion, suggestions, advice, solutions,
> rants
> >> and raves welcomed.
> >>
> >> Andrew Hole wrote ..
> >>
> >>> Hello
> >>>
> >>> I read an interesting document from Mladen Turk (with whom I want to
> >>>
> >> speak
> >>
> >>> directly, but I don't know direct contact) that there is a formula to
> >>> calculate the number of concurrent request:
> >>> http://people.apache.org/~mturk/docs/article/ftwai.html
> >>>
> >>> Calculating Load
> >>>
> >>> When determining the number of Tomcat servers that you will need to
> >>>
> >> satisfy
> >>
> >>> the client load, the first and major task is determining the Average
> >>> Application Response Time (hereafter AART). As said before, to satisfy
> >>>
> >> the
> >>
> >>> user experience the application has to respond withi

Re: Tomcat Performance

[Leon Rosenberg]

I would be interested how much performance you were able to tickle
compared to default jvm settings?
Leon

And how many of the settings had to be reverted with switch to a newer
jdk, if any.

On Jan 31, 2008 3:49 AM, Peter Lin <[EMAIL PROTECTED]> wrote:
> from past experience, it's much better to use hardware load balancing. At a
> previous job, we had any where from 12-24 servers load balanced behind a
> cisco local director.
>
> Any load balancing router today can do the job, it doesn't have to be
> cisco.  What I did in the past was to take production logs and run them in
> jmeter against a cluster of tomcat servers. All the servers were behind the
> load balancer.
>
> After the test was run, we collected the logs to make sure the load was
> distributed evenly and we generated reports. From those reports, we compared
> the results of the new system against the system we were replacing.
>
> That established the baseline performance for untuned tomcat. I then spent a
> week going through 10 different jvm settings and running a full set of
> benchmarks on each. At the end I looked at what concurrent loads the entire
> system needed to support and chose the settings that match those needs. In
> my test suite, I varied the number of concurrent connections, think time
> between requests, ramp up time and a mix of requests.
>
> the key to tuning the system correctly is understanding exactly what kind of
> traffic you expect. of course that isn't always possible, so you might have
> to take a guess.
>
> peter
>
>
> On 1/30/08, David Brown <[EMAIL PROTECTED]> wrote:
> >
> > Hello Andrew, reading your email, Alan's email and the Mladen email piqued
> > my interest because I am currently working on a gig to improve the
> > performance and monitoring of two Tomcat instances supporting 3 web
> > applications and one web service. I am inclined to agree with Alan. And, did
> > you read the ML replies to the Xmx and Xms Subject line emails? I must agree
> > with the ML contributors that answered the email named in the previous
> > sentence: baseline test, apply Eden parameters to the JVM then monitor the
> > results of the load testing. Once you have all your monitoring results
> > including logs the next step is to create a new metric by comparing the
> > newly acquired data to your initial baseline test. There are very good
> > points made on both sides but I have to believe that Tomcat tuning a priori
> > is like trying to predict the weather. In my gig there are too many unknowns
> > to resolve:
> > (1) this is a legacy system which means differing verions of JDKs, Tomcat
> > instances, web apps or web services built with framework versions no longer
> > supported e.g. AXIS 1.3.
> > (2) Commercial vendors that have taken FOSS and re-packaged it as
> > proprietary software and as a result there is no direct support from the
> > vendors for: SLA source code or updated binaries that were written in this
> > century.
> > (3) I know my client wants everything upgraded and migrated if possible
> > when in reality I will have to improve the monitoring and performance issues
> > with the current servlet containers, web services and network topology as it
> > stands now.
> >
> > I know the rest of the world is moving away from clustering (horizontal
> > scaling) and more toward virtualization (vertical scaling). In my case I
> > will have to settle for horizontal scaling and the Tomcat software load
> > balancing. I welcome anyone wanting to expound on Tomcat load balancing:
> > say, a comparison between Tomcat JK connector load balancing and using an
> > appliance like Big IP.
> >
> > Like you Andrew I would cheer a  solution if it existed: just
> > dump in the number of nodes, instances, network(s), applications, web
> > services, bandwidth and client users and viola! out comes the network
> > diagram with annotations. Discussion, suggestions, advice, solutions, rants
> > and raves welcomed.
> >
> > Andrew Hole wrote ..
> > > Hello
> > >
> > > I read an interesting document from Mladen Turk (with whom I want to
> > speak
> > > directly, but I don't know direct contact) that there is a formula to
> > > calculate the number of concurrent request:
> > > http://people.apache.org/~mturk/docs/article/ftwai.html
> > >
> > > Calculating Load
> > >
> > > When determining the number of Tomcat servers that you will need to
> > satisfy
> > > the client load, the first and major task is determining the Average
> > > Application Response Time (hereafter AART). As said before, to satisfy
> > the
> > > user experience the application has to respond within half of second.
> > The
> > > content received by the client browser usually triggers couple of
> > physical
> > > requests to the Web server (e.g. images). The web page usually consists
> > of
> > > html and image data, so client issues a series of requests, and the time
> > > that all this gets processed and delivered is called AART. To get most
> > out
> > > of Tomcat you should limi

Re: Tomcat Performance

[andrey.morskoy]

About cisco: Peter Lin, what was the model in your case?
Was it able to replicate sessions (sticky session maybe ) ?

Peter Lin wrote:

from past experience, it's much better to use hardware load balancing. At a
previous job, we had any where from 12-24 servers load balanced behind a
cisco local director.

Any load balancing router today can do the job, it doesn't have to be
cisco.  What I did in the past was to take production logs and run them in
jmeter against a cluster of tomcat servers. All the servers were behind the
load balancer.

After the test was run, we collected the logs to make sure the load was
distributed evenly and we generated reports. From those reports, we compared
the results of the new system against the system we were replacing.

That established the baseline performance for untuned tomcat. I then spent a
week going through 10 different jvm settings and running a full set of
benchmarks on each. At the end I looked at what concurrent loads the entire
system needed to support and chose the settings that match those needs. In
my test suite, I varied the number of concurrent connections, think time
between requests, ramp up time and a mix of requests.

the key to tuning the system correctly is understanding exactly what kind of
traffic you expect. of course that isn't always possible, so you might have
to take a guess.

peter

On 1/30/08, David Brown <[EMAIL PROTECTED]> wrote:
  

Hello Andrew, reading your email, Alan's email and the Mladen email piqued
my interest because I am currently working on a gig to improve the
performance and monitoring of two Tomcat instances supporting 3 web
applications and one web service. I am inclined to agree with Alan. And, did
you read the ML replies to the Xmx and Xms Subject line emails? I must agree
with the ML contributors that answered the email named in the previous
sentence: baseline test, apply Eden parameters to the JVM then monitor the
results of the load testing. Once you have all your monitoring results
including logs the next step is to create a new metric by comparing the
newly acquired data to your initial baseline test. There are very good
points made on both sides but I have to believe that Tomcat tuning a priori
is like trying to predict the weather. In my gig there are too many unknowns
to resolve:
(1) this is a legacy system which means differing verions of JDKs, Tomcat
instances, web apps or web services built with framework versions no longer
supported e.g. AXIS 1.3.
(2) Commercial vendors that have taken FOSS and re-packaged it as
proprietary software and as a result there is no direct support from the
vendors for: SLA source code or updated binaries that were written in this
century.
(3) I know my client wants everything upgraded and migrated if possible
when in reality I will have to improve the monitoring and performance issues
with the current servlet containers, web services and network topology as it
stands now.

I know the rest of the world is moving away from clustering (horizontal
scaling) and more toward virtualization (vertical scaling). In my case I
will have to settle for horizontal scaling and the Tomcat software load
balancing. I welcome anyone wanting to expound on Tomcat load balancing:
say, a comparison between Tomcat JK connector load balancing and using an
appliance like Big IP.

Like you Andrew I would cheer a  solution if it existed: just
dump in the number of nodes, instances, network(s), applications, web
services, bandwidth and client users and viola! out comes the network
diagram with annotations. Discussion, suggestions, advice, solutions, rants
and raves welcomed.

Andrew Hole wrote ..


Hello

I read an interesting document from Mladen Turk (with whom I want to
  

speak


directly, but I don't know direct contact) that there is a formula to
calculate the number of concurrent request:
http://people.apache.org/~mturk/docs/article/ftwai.html

Calculating Load

When determining the number of Tomcat servers that you will need to
  

satisfy


the client load, the first and major task is determining the Average
Application Response Time (hereafter AART). As said before, to satisfy
  

the


user experience the application has to respond within half of second.
  

The


content received by the client browser usually triggers couple of
  

physical


requests to the Web server (e.g. images). The web page usually consists
  

of


html and image data, so client issues a series of requests, and the time
that all this gets processed and delivered is called AART. To get most
  

out


of Tomcat you should limit the number of concurrent requests to 200 per
  

CPU.


So we can come with the simple formula to calculate the maximum number
  

of


concurrent connections a physical box can handle:

  500
Concurrent requests = ( -- max 200 ) * Number of CPU's
AART (ms)

The 

Re: Tomcat Performance

[Peter Lin]

from past experience, it's much better to use hardware load balancing. At a
previous job, we had any where from 12-24 servers load balanced behind a
cisco local director.

Any load balancing router today can do the job, it doesn't have to be
cisco.  What I did in the past was to take production logs and run them in
jmeter against a cluster of tomcat servers. All the servers were behind the
load balancer.

After the test was run, we collected the logs to make sure the load was
distributed evenly and we generated reports. From those reports, we compared
the results of the new system against the system we were replacing.

That established the baseline performance for untuned tomcat. I then spent a
week going through 10 different jvm settings and running a full set of
benchmarks on each. At the end I looked at what concurrent loads the entire
system needed to support and chose the settings that match those needs. In
my test suite, I varied the number of concurrent connections, think time
between requests, ramp up time and a mix of requests.

the key to tuning the system correctly is understanding exactly what kind of
traffic you expect. of course that isn't always possible, so you might have
to take a guess.

peter

On 1/30/08, David Brown <[EMAIL PROTECTED]> wrote:
>
> Hello Andrew, reading your email, Alan's email and the Mladen email piqued
> my interest because I am currently working on a gig to improve the
> performance and monitoring of two Tomcat instances supporting 3 web
> applications and one web service. I am inclined to agree with Alan. And, did
> you read the ML replies to the Xmx and Xms Subject line emails? I must agree
> with the ML contributors that answered the email named in the previous
> sentence: baseline test, apply Eden parameters to the JVM then monitor the
> results of the load testing. Once you have all your monitoring results
> including logs the next step is to create a new metric by comparing the
> newly acquired data to your initial baseline test. There are very good
> points made on both sides but I have to believe that Tomcat tuning a priori
> is like trying to predict the weather. In my gig there are too many unknowns
> to resolve:
> (1) this is a legacy system which means differing verions of JDKs, Tomcat
> instances, web apps or web services built with framework versions no longer
> supported e.g. AXIS 1.3.
> (2) Commercial vendors that have taken FOSS and re-packaged it as
> proprietary software and as a result there is no direct support from the
> vendors for: SLA source code or updated binaries that were written in this
> century.
> (3) I know my client wants everything upgraded and migrated if possible
> when in reality I will have to improve the monitoring and performance issues
> with the current servlet containers, web services and network topology as it
> stands now.
>
> I know the rest of the world is moving away from clustering (horizontal
> scaling) and more toward virtualization (vertical scaling). In my case I
> will have to settle for horizontal scaling and the Tomcat software load
> balancing. I welcome anyone wanting to expound on Tomcat load balancing:
> say, a comparison between Tomcat JK connector load balancing and using an
> appliance like Big IP.
>
> Like you Andrew I would cheer a  solution if it existed: just
> dump in the number of nodes, instances, network(s), applications, web
> services, bandwidth and client users and viola! out comes the network
> diagram with annotations. Discussion, suggestions, advice, solutions, rants
> and raves welcomed.
>
> Andrew Hole wrote ..
> > Hello
> >
> > I read an interesting document from Mladen Turk (with whom I want to
> speak
> > directly, but I don't know direct contact) that there is a formula to
> > calculate the number of concurrent request:
> > http://people.apache.org/~mturk/docs/article/ftwai.html
> >
> > Calculating Load
> >
> > When determining the number of Tomcat servers that you will need to
> satisfy
> > the client load, the first and major task is determining the Average
> > Application Response Time (hereafter AART). As said before, to satisfy
> the
> > user experience the application has to respond within half of second.
> The
> > content received by the client browser usually triggers couple of
> physical
> > requests to the Web server (e.g. images). The web page usually consists
> of
> > html and image data, so client issues a series of requests, and the time
> > that all this gets processed and delivered is called AART. To get most
> out
> > of Tomcat you should limit the number of concurrent requests to 200 per
> CPU.
> >
> > So we can come with the simple formula to calculate the maximum number
> of
> > concurrent connections a physical box can handle:
> >
> >   500
> > Concurrent requests = ( -- max 200 ) * Number of CPU's
> > AART (ms)
> >
> > The other thing that you must care is the Network throughput between the
> Web

Re: Tomcat Performance

[David Brown]

Hello Andrew, reading your email, Alan's email and the Mladen email piqued my 
interest because I am currently working on a gig to improve the performance and 
monitoring of two Tomcat instances supporting 3 web applications and one web 
service. I am inclined to agree with Alan. And, did you read the ML replies to 
the Xmx and Xms Subject line emails? I must agree with the ML contributors that 
answered the email named in the previous sentence: baseline test, apply Eden 
parameters to the JVM then monitor the results of the load testing. Once you 
have all your monitoring results including logs the next step is to create a 
new metric by comparing the newly acquired data to your initial baseline test. 
There are very good points made on both sides but I have to believe that Tomcat 
tuning a priori is like trying to predict the weather. In my gig there are too 
many unknowns to resolve: 
(1) this is a legacy system which means differing verions of JDKs, Tomcat 
instances, web apps or web services built with framework versions no longer 
supported e.g. AXIS 1.3. 
(2) Commercial vendors that have taken FOSS and re-packaged it as proprietary 
software and as a result there is no direct support from the vendors for: SLA 
source code or updated binaries that were written in this century.
(3) I know my client wants everything upgraded and migrated if possible when in 
reality I will have to improve the monitoring and performance issues with the 
current servlet containers, web services and network topology as it stands now.

I know the rest of the world is moving away from clustering (horizontal 
scaling) and more toward virtualization (vertical scaling). In my case I will 
have to settle for horizontal scaling and the Tomcat software load balancing. I 
welcome anyone wanting to expound on Tomcat load balancing: say, a comparison 
between Tomcat JK connector load balancing and using an appliance like Big IP.

Like you Andrew I would cheer a  solution if it existed: just dump 
in the number of nodes, instances, network(s), applications, web services, 
bandwidth and client users and viola! out comes the network diagram with 
annotations. Discussion, suggestions, advice, solutions, rants and raves 
welcomed.

Andrew Hole wrote ..
> Hello
> 
> I read an interesting document from Mladen Turk (with whom I want to speak
> directly, but I don't know direct contact) that there is a formula to
> calculate the number of concurrent request:
> http://people.apache.org/~mturk/docs/article/ftwai.html
> 
> Calculating Load
> 
> When determining the number of Tomcat servers that you will need to satisfy
> the client load, the first and major task is determining the Average
> Application Response Time (hereafter AART). As said before, to satisfy the
> user experience the application has to respond within half of second. The
> content received by the client browser usually triggers couple of physical
> requests to the Web server (e.g. images). The web page usually consists of
> html and image data, so client issues a series of requests, and the time
> that all this gets processed and delivered is called AART. To get most out
> of Tomcat you should limit the number of concurrent requests to 200 per CPU.
> 
> So we can come with the simple formula to calculate the maximum number of
> concurrent connections a physical box can handle:
> 
>   500
> Concurrent requests = ( -- max 200 ) * Number of CPU's
> AART (ms)
> 
> The other thing that you must care is the Network throughput between the Web
> server and Tomcat instances. This introduces a new variable called Average
> Application Response Size (hereafter AARS), that is the number of bytes of
> all context on a web page presented to the user. On a standard 100Mbps
> network card with 8 Bits per Byte, the maximum theoretical throughput is
> 12.5 MBytes.
> 
>12500
> Concurrent requests = ---
> AARS (KBytes)
> 
> For a 20KB AARS this will give a theoretical maximum of 625 concurrent
> requests. You can add more cards or use faster 1Gbps hardware if need to
> handle more load.
> 
> The formulas above will give you rudimentary estimation of the number of
> Tomcat boxes and CPU's that you will need to handle the desired number of
> concurrent client requests. If you have to deploy the configuration without
> having actual hardware, the closest you can get is to measure the AART on a
> test platform and then compare the hardware vendor Specmarks.
> 
> I would like to launch a discussion on the validity of this formula and, in
> case of inappropriate, to try to get a more accurate formula.
> 
> Thanks a lot

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RE: Tomcat Performance

[Peter Crowther]

> From: Alan Chaney [mailto:[EMAIL PROTECTED]
> Unfortunately I think it is way more complicated than this.

Seconded.

Andrew, you keep mailing this list looking for simple, neat and clean ways of 
working out the maximum capability of a Tomcat application.  There aren't any!

The *only* reliable approach is to profile your application, on your target 
hardware, with a representative load.  Even then, your answers may change if 
you scale that hardware - and the change may be horribly non-linear.  To take a 
simple example, an application that behaves well with one front-end server and 
one database server may degrade with 2 front-end servers so that the overall 
throughput and response times are both *worse* than with the single front-end 
server, because database lock contention has increased and is delaying request 
completion of all requests on both servers.  In general, when a team finds this 
is the case, there's much wailing and gnashing of teeth, along with a "but... 
but... but the world doesn't work like that!" from the people who've never seen 
something like it before.

If I recall, you've never told us why you want these numbers.  Are you writing 
a business case or business plan?  If so, the section on scaling and hardware 
costs needs a big health warning on it:  "These numbers are wild guesses and 
could be an order of magnitude out, depending on tiny details of how the system 
is actually implemented."  If your managers or investers are experienced, 
they'll know this anyway - and there's no point hiding it from them.  If the 
case for the project turns on how much the hardware is going to cost, you have 
a much bigger problem anyway, which is that the return on investment is so 
marginal that the project probably *shouldn't* be funded.  And, finally, if the 
hardware cost is significant, then put more in the budget for good developers, 
and extra time for performance tuning.  If the farm is sufficiently large, 
better brains are cheaper than more iron.  Many/most "practical" scaling 
problems can be reduced or solved completely by finding the badly-written piece 
of code or poorly-indexed SQL table that's causing 90% of the problem, and 
fixing it.

- Peter
--
Peter Crowther, Director, Melandra Limited

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Re: Tomcat Performance

[Leon Rosenberg]

Without wanting to oppose the whole document, the parts you quoted are
pretty incomplete.

first, calculating AART from clients perespective (as implicitely done
in the article) is not a good idea, since you are
mixing up tomcat response time, network transport, internet latency,
all in one bunch. Why should tomcat care about the data once it left
its buffers?

Second, and most serious flaw of the article, is the inability to
differ between net and gross request duration. There are more
resources needed on the server besides the cpu. Disk io costs time
too.
With a AART of 1 second and one cpu you can still handle 10 requests
per second if the net request duration is 0.1 seconds, even the gross
duration is 1 second or more.

regards
Leon


On Jan 29, 2008 3:11 PM, Andrew Hole <[EMAIL PROTECTED]> wrote:
> Hello
>
> I read an interesting document from Mladen Turk (with whom I want to speak
> directly, but I don't know direct contact) that there is a formula to
> calculate the number of concurrent request:
> http://people.apache.org/~mturk/docs/article/ftwai.html
>
> Calculating Load
>
> When determining the number of Tomcat servers that you will need to satisfy
> the client load, the first and major task is determining the Average
> Application Response Time (hereafter AART). As said before, to satisfy the
> user experience the application has to respond within half of second. The
> content received by the client browser usually triggers couple of physical
> requests to the Web server (e.g. images). The web page usually consists of
> html and image data, so client issues a series of requests, and the time
> that all this gets processed and delivered is called AART. To get most out
> of Tomcat you should limit the number of concurrent requests to 200 per CPU.
>
> So we can come with the simple formula to calculate the maximum number of
> concurrent connections a physical box can handle:
>
>   500
> Concurrent requests = ( -- max 200 ) * Number of CPU's
> AART (ms)
>
> The other thing that you must care is the Network throughput between the Web
> server and Tomcat instances. This introduces a new variable called Average
> Application Response Size (hereafter AARS), that is the number of bytes of
> all context on a web page presented to the user. On a standard 100Mbps
> network card with 8 Bits per Byte, the maximum theoretical throughput is
> 12.5 MBytes.
>
>12500
> Concurrent requests = ---
> AARS (KBytes)
>
> For a 20KB AARS this will give a theoretical maximum of 625 concurrent
> requests. You can add more cards or use faster 1Gbps hardware if need to
> handle more load.
>
> The formulas above will give you rudimentary estimation of the number of
> Tomcat boxes and CPU's that you will need to handle the desired number of
> concurrent client requests. If you have to deploy the configuration without
> having actual hardware, the closest you can get is to measure the AART on a
> test platform and then compare the hardware vendor Specmarks.
>
> I would like to launch a discussion on the validity of this formula and, in
> case of inappropriate, to try to get a more accurate formula.
>
> Thanks a lot
>

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Re: Tomcat Performance

[Alan Chaney]

Unfortunately I think it is way more complicated than this.

I think that Mladen Turk's article has a lot of very useful information 
about configuring Tomcat and I congratulate him on putting it together. 
However, I've spent some time recently working on some performance 
issues and I think that for any given installation you must consider a 
number of factors.


These include:

1. The time it takes to prepare the data for delivery.

2. The way available resources are combined in the delivery of this data.

1. The database

Where a database or some other persistence mechanism is involved the
performance of the database can easily overwhelm almost all other 
considerations.


Is the database local or remote? If local, the time taken transferring 
results from the database to the business layer may not be that 
significant but the cpu time and disk I/O spent running the query will 
immediately reduce the resources available and thus increase the 
response time of web requests.


If remote then it is easy for the database to become a bottleneck for 
requests. Also the time transferring the data over the network becomes 
more significant and it is arithmetically added to the AART unless the 
data can be 'preread' and cached.


How well designed are the queries? Are they subject to issues such as 
badly designed indexes which mean that as the data set grows query 
processing time responds exponentially? Has the object design been 
tested for performance - an ORM solution can save a lot of time in 
development but add significant 'hidden' costs. [Please note, I think 
ORMs are a great idea and always use them where possible but like all 
technology they have their drawbacks!]



2. The mix of the need for resources by the application.

Issues to consider here include:

Are sessions required, and the size of the session. This can also 
significantly impact clustered performance. It may be better to keep 
keys for information in the session and re-read the data rather than 
read data once at the beginning of the session.


What processing is required in the business/web layer to structure the 
information? Is there significant XML processing (which can be very time 
intensive?) Is there significant EL processing on a page (which can be 
much slower than 'raw' java')


My experience is that the only way to really assess the overall 
performance of a system is to instrument the system extensively and then 
monitor it in action. Doing this will sometimes reveal bottlenecks which 
you just didn't consider. Of course even then you must be careful of 
'the Heisenberg effect'.


One final point. In Mladen Turk's example he assumes that the full 
bitrate bandwidth of an Ethernet connection is available for useful 
data. From previous experience I have seen that the overhead of the 
protocol and framing information reduce the 100 Mbps to more like 70 
Mbps which would change his max of 625 concurrent requests to about 440.


Another network related issue is that actually most client 'last hop' 
connections are considerably slower than 100 Mbps. Where TCP/IP is 
involved the thread which is actually writing to the network interface 
will block until the *client* has read all the data and indicated that 
the transmission is successfully completed.


In conclusion I think that if you apply two simple formulae to the 
design of a Tomcat based web application you may be shocked and 
surprised at the actual results unless you have very carefully analysed 
your design and investigated the factors which affect performance.


Regards

Alan



Andrew Hole wrote:

Hello

I read an interesting document from Mladen Turk (with whom I want to speak
directly, but I don't know direct contact) that there is a formula to
calculate the number of concurrent request:
http://people.apache.org/~mturk/docs/article/ftwai.html

Calculating Load

When determining the number of Tomcat servers that you will need to satisfy
the client load, the first and major task is determining the Average
Application Response Time (hereafter AART). As said before, to satisfy the
user experience the application has to respond within half of second. The
content received by the client browser usually triggers couple of physical
requests to the Web server (e.g. images). The web page usually consists of
html and image data, so client issues a series of requests, and the time
that all this gets processed and delivered is called AART. To get most out
of Tomcat you should limit the number of concurrent requests to 200 per CPU.

So we can come with the simple formula to calculate the maximum number of
concurrent connections a physical box can handle:

  500
Concurrent requests = ( -- max 200 ) * Number of CPU's
AART (ms)

The other thing that you must care is the Network throughput between the Web
server and Tomcat instances. This introduces a new variable called Average
Application Response Size (hereafte

Re: Tomcat Performance Question

[mgainty]

Good Point
suggest taking a look at implementing Tomcat Clustering to accomodate
greater loads
http://wiki.apache.org/tomcat/FAQ/Clustering

M-
- Original Message -
Wrom: VRESKPNKMBIPBARHDMNNSKVFVWRKJVZCMHVIB
To: "Tomcat Users List" 
Sent: Saturday, January 26, 2008 2:18 PM
Subject: Re: Tomcat Performance Question


> Ali Ok wrote:
> > Thanks David,
> >
> > I mean, if I make 3 requests in a very short time (about 10
seconds);
> > Tomcat does not respond.
> > I read books, tutorials, faqs and threads at maling list about Tomcat
> > tuning. But I couldnt find an example server.xml file used in production
or
> > real test results.
> >
> > So I cant understand if 3 requests in 10 seconds is normal or not.
> >
> 3000 requests per second is something on the order of what microsoft
> gets on its entire set of websites (microsoft.com, hotmail, live, etc,
> all combined), and they have a big server farm running it.  That's a lot
> of requests, and you need to provision your hardware and bandwidth
> accordingly.
>
> D
>
>
>
> -
> To start a new topic, e-mail: users@tomcat.apache.org
> To unsubscribe, e-mail: [EMAIL PROTECTED]
> For additional commands, e-mail: [EMAIL PROTECTED]
>
>


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Re: Tomcat Performance Question

[David Kerber]

Ali Ok wrote:

Thanks David,

I mean, if I make 3 requests in a very short time (about 10 seconds);
Tomcat does not respond.
I read books, tutorials, faqs and threads at maling list about Tomcat
tuning. But I couldnt find an example server.xml file used in production or
real test results.

So I cant understand if 3 requests in 10 seconds is normal or not.
  
3000 requests per second is something on the order of what microsoft 
gets on its entire set of websites (microsoft.com, hotmail, live, etc, 
all combined), and they have a big server farm running it.  That's a lot 
of requests, and you need to provision your hardware and bandwidth 
accordingly.


D



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Re: Tomcat Performance Question

[Peter Lin]

have you tried monitoring the CPU and IO usage of the system during the
test?

In the past, when I stress test an application, I monitor the cpu and io, to
determine which part is getting maxed out first. For example, if I was
serving up static pages, the first thing to mak out is the IO, so even
though tomcat could handle greater loads, it can't because of the IO. What I
usually do is identify the bottlenecks in the application by testing each
part separately. Once I know the max through of each component, I ran the
stress test with JMeter.

If you haven't measured each piece individually, it will be difficult to
figure why the application is slow.

hope that helps

peter

On Jan 26, 2008 11:32 AM, Ali Ok <[EMAIL PROTECTED]> wrote:

> Peter, thats ok, maybe some day we can get that much hit :)
>
> What if someone make so much requests and confuse the server?
> Does Tomcat have an prevention for this situation? Or is it beyond the
> scope?
>
> David, I have already read all of resources you sent.
>
> Invariably performance issues are rarely a result of the web container
> > (Tomcat). You need to look at the developed software (dot).war that is
> > deployed on TC (use JMeter or some recognized software testing tools).
>
>
>
>
> * You are hitting your TC with 3 transactions with a ramp up speed of
> 10
> > seconds so you are at 3000/sec. If as you say the web container is not
> > handling this you still need to look at what you web application is
> doing.
> >
>
> I dont talk about my application. It may contain bugs or incorrect logic,
> blaming Tomcat is not my intention. Many people thank developers and I
> admire Apache SF.
>
> I make that test of mine with "Shuffle Example" comes with Tomcat (XXX
> /examples/jsp/jsp2/jspattribute/shuffle.jsp). And it is a simple JSP page,
> cannot contain bugs :)
>
> * What is your planned network topology once you go to production? This
> > question naturally leads to what is your hosting options? If you   have
> a
> > datacenter and have configured and installed your own servers is the
> best.
> > Next option is to build your servers and then co-locate. The least
> > advantageous option is renting servers (serverbeach.com etc.). If you
> are
> > hosting locally what is your upstream provider? (fat pipe) and type of
> > connection: T1, T3, OC1, OC3 etc.
> > * Type of scaling (horizontal vs vertical)
> >
>
> My purpose is finding out the limits of Tomcat with constant resources at
> the moment. Then I will continue with these.
>
>
> I just want to have an idea in general. However its better to give
> details.
>
> OS: Debian 4.0 r0 on VmWare
> RAM assigned to virtual machine: 1 gb
> CPU: Intel Core 2 Duo, 2 Ghz etc.
> Tomcat: 6.0.13
>
>
> My starting script:
>
> /home/kullanici/Desktop/programlar/jdk1.6.0_03/bin/java -Xmx256m -Xms128m
> -
> Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -
>
> Djava.util.logging.config.file=/home/kullanici/Desktop/programlar/Tomcat_6_win/conf/logging.properties-
>
> Djava.endorsed.dirs=/home/kullanici/Desktop/programlar/Tomcat_6_win/endorsed-classpath
>
> :/home/kullanici/Desktop/programlar/Tomcat_6_win/bin/bootstrap.jar:/home/kullanici/Desktop/programlar/Tomcat_6_win/bin/commons-
> logging-api.jar -
> Dcatalina.base=/home/kullanici/Desktop/programlar/Tomcat_6_win -
> Dcatalina.home=/home/kullanici/Desktop/programlar/Tomcat_6_win -
> Djava.io.tmpdir=/home/kullanici/Desktop/programlar/Tomcat_6_win/temp
> org.apache.catalina.startup.Bootstrap start
>
>
> Thank you, Peter and David
>
>
>
> 2008/1/26, David Brown <[EMAIL PROTECTED]>:
> >
> > Hello Ali, there are no absolute benchmarks for what you are looking
> for.
> > The central theme to any performance questions invariably lead to the
> 
> > word (Architecture). You need to evaluate you overall architecture from
> a
> > high level perspective. With this said the questions then are:
> > * What is your planned network topology once you go to production? This
> > question naturally leads to what is your hosting options? If you   have
> a
> > datacenter and have configured and installed your own servers is the
> best.
> > Next option is to build your servers and then co-locate. The least
> > advantageous option is renting servers (serverbeach.com etc.). If you
> are
> > hosting locally what is your upstream provider? (fat pipe) and type of
> > connection: T1, T3, OC1, OC3 etc.
> > * Type of scaling (horizontal vs vertical)
> > * Invariably performance issues are rarely a result of the web container
> > (Tomcat). You need to look at the developed software (dot).war that is
> > deployed on TC (use JMeter or some recognized software testing tools).
> > * I have worked on high volume financial web applications that are
> running
> > at 3 to 4000 transactions/sec. A transaction is end-to-end a round-trip
> time
> > starting with the HTTP connection, processing and connection to the
> backend
> > DB, query results returned and subsequently a results web page
> displayed.
> > Th

RE: Tomcat Performance Question

[Caldarale, Charles R]

> From: Ali Ok [mailto:[EMAIL PROTECTED] 
> Subject: Re: Tomcat Performance Question
> 
> What if someone make so much requests and confuse the server?
> Does Tomcat have an prevention for this situation?

You can configure the maximum number of requests a  will
handle concurrently, as well as the maximum number Tomcat will queue for
the  before discarding them:
http://tomcat.apache.org/tomcat-6.0-doc/config/http.html

See the 3rd paragraph of the Introduction.

 - Chuck


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Re: Tomcat Performance Question

[Ali Ok]

Peter, thats ok, maybe some day we can get that much hit :)

What if someone make so much requests and confuse the server?
Does Tomcat have an prevention for this situation? Or is it beyond the
scope?

David, I have already read all of resources you sent.

Invariably performance issues are rarely a result of the web container
> (Tomcat). You need to look at the developed software (dot).war that is
> deployed on TC (use JMeter or some recognized software testing tools).




* You are hitting your TC with 3 transactions with a ramp up speed of 10
> seconds so you are at 3000/sec. If as you say the web container is not
> handling this you still need to look at what you web application is doing.
>

I dont talk about my application. It may contain bugs or incorrect logic,
blaming Tomcat is not my intention. Many people thank developers and I
admire Apache SF.

I make that test of mine with "Shuffle Example" comes with Tomcat (XXX
/examples/jsp/jsp2/jspattribute/shuffle.jsp). And it is a simple JSP page,
cannot contain bugs :)

* What is your planned network topology once you go to production? This
> question naturally leads to what is your hosting options? If you   have a
> datacenter and have configured and installed your own servers is the best.
> Next option is to build your servers and then co-locate. The least
> advantageous option is renting servers (serverbeach.com etc.). If you are
> hosting locally what is your upstream provider? (fat pipe) and type of
> connection: T1, T3, OC1, OC3 etc.
> * Type of scaling (horizontal vs vertical)
>

My purpose is finding out the limits of Tomcat with constant resources at
the moment. Then I will continue with these.


I just want to have an idea in general. However its better to give details.

OS: Debian 4.0 r0 on VmWare
RAM assigned to virtual machine: 1 gb
CPU: Intel Core 2 Duo, 2 Ghz etc.
Tomcat: 6.0.13


My starting script:

/home/kullanici/Desktop/programlar/jdk1.6.0_03/bin/java -Xmx256m -Xms128m -
Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -
Djava.util.logging.config.file=/home/kullanici/Desktop/programlar/Tomcat_6_win/conf/logging.properties-
Djava.endorsed.dirs=/home/kullanici/Desktop/programlar/Tomcat_6_win/endorsed-classpath
:/home/kullanici/Desktop/programlar/Tomcat_6_win/bin/bootstrap.jar:/home/kullanici/Desktop/programlar/Tomcat_6_win/bin/commons-
logging-api.jar -
Dcatalina.base=/home/kullanici/Desktop/programlar/Tomcat_6_win -
Dcatalina.home=/home/kullanici/Desktop/programlar/Tomcat_6_win -
Djava.io.tmpdir=/home/kullanici/Desktop/programlar/Tomcat_6_win/temp
org.apache.catalina.startup.Bootstrap start


Thank you, Peter and David



2008/1/26, David Brown <[EMAIL PROTECTED]>:
>
> Hello Ali, there are no absolute benchmarks for what you are looking for.
> The central theme to any performance questions invariably lead to the 
> word (Architecture). You need to evaluate you overall architecture from a
> high level perspective. With this said the questions then are:
> * What is your planned network topology once you go to production? This
> question naturally leads to what is your hosting options? If you   have a
> datacenter and have configured and installed your own servers is the best.
> Next option is to build your servers and then co-locate. The least
> advantageous option is renting servers (serverbeach.com etc.). If you are
> hosting locally what is your upstream provider? (fat pipe) and type of
> connection: T1, T3, OC1, OC3 etc.
> * Type of scaling (horizontal vs vertical)
> * Invariably performance issues are rarely a result of the web container
> (Tomcat). You need to look at the developed software (dot).war that is
> deployed on TC (use JMeter or some recognized software testing tools).
> * I have worked on high volume financial web applications that are running
> at 3 to 4000 transactions/sec. A transaction is end-to-end a round-trip time
> starting with the HTTP connection, processing and connection to the backend
> DB, query results returned and subsequently a results web page displayed.
> This is a HTTP get, put or post transaction.
> * You are hitting your TC with 3 transactions with a ramp up speed of
> 10 seconds so you are at 3000/sec. If as you say the web container is not
> handling this you still need to look at what you web application is doing.
>
> Ultimately, using JMeter you need to look here:
> http://wiki.apache.org/jakarta-jmeter/
>
> A expert in this area is Peter Lin:
> http://tomcat.apache.org/articles/performance.pdf
>
> The JMeter has specific JSF testing reading:
> http://wiki.apache.org/myfaces/PerformanceTestingWithJMeter
>
> Ali Ok wrote ..
> > Thanks David,
> >
> > I mean, if I make 3 requests in a very short time (about 10
> seconds);
> > Tomcat does not respond.
> > I read books, tutorials, faqs and threads at maling list about Tomcat
> > tuning. But I couldnt find an example server.xml file used in production
> or
> > real test results.
> >
> > So I cant understand if 3 reques

Re: Tomcat Performance Question

[David Brown]

Hello Ali, there are no absolute benchmarks for what you are looking for. The 
central theme to any performance questions invariably lead to the  word 
(Architecture). You need to evaluate you overall architecture from a high level 
perspective. With this said the questions then are:
* What is your planned network topology once you go to production? This 
question naturally leads to what is your hosting options? If you   have a 
datacenter and have configured and installed your own servers is the best. Next 
option is to build your servers and then co-locate. The least advantageous 
option is renting servers (serverbeach.com etc.). If you are hosting locally 
what is your upstream provider? (fat pipe) and type of connection: T1, T3, OC1, 
OC3 etc.
* Type of scaling (horizontal vs vertical)
* Invariably performance issues are rarely a result of the web container 
(Tomcat). You need to look at the developed software (dot).war that is deployed 
on TC (use JMeter or some recognized software testing tools).
* I have worked on high volume financial web applications that are running at 3 
to 4000 transactions/sec. A transaction is end-to-end a round-trip time 
starting with the HTTP connection, processing and connection to the backend DB, 
query results returned and subsequently a results web page displayed. This is a 
HTTP get, put or post transaction.
* You are hitting your TC with 3 transactions with a ramp up speed of 10 
seconds so you are at 3000/sec. If as you say the web container is not handling 
this you still need to look at what you web application is doing.

Ultimately, using JMeter you need to look here:
http://wiki.apache.org/jakarta-jmeter/

A expert in this area is Peter Lin:
http://tomcat.apache.org/articles/performance.pdf

The JMeter has specific JSF testing reading:
http://wiki.apache.org/myfaces/PerformanceTestingWithJMeter

Ali Ok wrote ..
> Thanks David,
> 
> I mean, if I make 3 requests in a very short time (about 10 seconds);
> Tomcat does not respond.
> I read books, tutorials, faqs and threads at maling list about Tomcat
> tuning. But I couldnt find an example server.xml file used in production or
> real test results.
> 
> So I cant understand if 3 requests in 10 seconds is normal or not.
> 
> 
> 
> 2008/1/26, David Brown <[EMAIL PROTECTED]>:
> >
> > Hello Ali, please find included below a link URL that addresses the JSF
> > performance issue. A much more rigorous test would be to use the JMeter
> > distributed testing using the JMeter server. HTH, David.
> >
> > Ali Ok wrote ..
> > > Hi,
> > >
> > > We are building a web application with JSF. Last day I tested it with
> > > JMeter. Results are bad (I guess).
> > >
> > > Then I tried to send 3 requests with JMeter to "Shuffle Example" in
> > > Tomcat's examples directory with a limited size of (256 MB I think)
> > memory
> > > resource given to Tomcat. This "Shuffle Example" does not query database
> > or
> > > does not make complicated operations as you know; it is very simple.
> > >
> > > Question is, what should I expect? Does it have to respond all requests?
> > Or
> > > is it normal to throw an exception about "Too many open files" (I use
> > NIO
> > > connector) and finally OutOfMemoryError and parachute-thing?
> > >
> > > After I solve this, I can go on to JSF application testing.
> > >
> > >
> > > I couldnt find documents enough about this issue. Can you send me some
> > > links?
> > >
> > > Thanks in advance.
> >
> > -
> > To start a new topic, e-mail: users@tomcat.apache.org
> > To unsubscribe, e-mail: [EMAIL PROTECTED]
> > For additional commands, e-mail: [EMAIL PROTECTED]
> >
> >

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Re: Tomcat Performance Question

[Peter Lin]

30,000 requests in 10 seconds probably isn't normal traffic, but it could
represent a sudden spike.

think of it another way, that's 3,000 requests per second. If we calculate
that for a 10 hour period, it puts things in perspective

1000 req/sec * 60 sec/min = 60,000 req/min
60,000 req/min * 60 min/hr = 3,600,000 req/hr
3,600,000 req/hr * 10 hr = 36,000,000 req

that means during normal work hours, the server would get 36 million
requests. to handle that kind of traffic, first you have to have the
bandwidth. There's an old performance article I wrote that's listed on
tomcat's article section. read that and see if it helps

peter

On Jan 26, 2008 10:14 AM, Ali Ok <[EMAIL PROTECTED]> wrote:

> Thanks David,
>
> I mean, if I make 3 requests in a very short time (about 10 seconds);
> Tomcat does not respond.
> I read books, tutorials, faqs and threads at maling list about Tomcat
> tuning. But I couldnt find an example server.xml file used in production
> or
> real test results.
>
> So I cant understand if 3 requests in 10 seconds is normal or not.
>
>
>
> 2008/1/26, David Brown <[EMAIL PROTECTED]>:
> >
> > Hello Ali, please find included below a link URL that addresses the JSF
> > performance issue. A much more rigorous test would be to use the JMeter
> > distributed testing using the JMeter server. HTH, David.
> >
> > Ali Ok wrote ..
> > > Hi,
> > >
> > > We are building a web application with JSF. Last day I tested it with
> > > JMeter. Results are bad (I guess).
> > >
> > > Then I tried to send 3 requests with JMeter to "Shuffle Example"
> in
> > > Tomcat's examples directory with a limited size of (256 MB I think)
> > memory
> > > resource given to Tomcat. This "Shuffle Example" does not query
> database
> > or
> > > does not make complicated operations as you know; it is very simple.
> > >
> > > Question is, what should I expect? Does it have to respond all
> requests?
> > Or
> > > is it normal to throw an exception about "Too many open files" (I use
> > NIO
> > > connector) and finally OutOfMemoryError and parachute-thing?
> > >
> > > After I solve this, I can go on to JSF application testing.
> > >
> > >
> > > I couldnt find documents enough about this issue. Can you send me some
> > > links?
> > >
> > > Thanks in advance.
> >
> > -
> > To start a new topic, e-mail: users@tomcat.apache.org
> > To unsubscribe, e-mail: [EMAIL PROTECTED]
> > For additional commands, e-mail: [EMAIL PROTECTED]
> >
> >
>

Re: Tomcat Performance Question

[Ali Ok]

Thanks David,

I mean, if I make 3 requests in a very short time (about 10 seconds);
Tomcat does not respond.
I read books, tutorials, faqs and threads at maling list about Tomcat
tuning. But I couldnt find an example server.xml file used in production or
real test results.

So I cant understand if 3 requests in 10 seconds is normal or not.



2008/1/26, David Brown <[EMAIL PROTECTED]>:
>
> Hello Ali, please find included below a link URL that addresses the JSF
> performance issue. A much more rigorous test would be to use the JMeter
> distributed testing using the JMeter server. HTH, David.
>
> Ali Ok wrote ..
> > Hi,
> >
> > We are building a web application with JSF. Last day I tested it with
> > JMeter. Results are bad (I guess).
> >
> > Then I tried to send 3 requests with JMeter to "Shuffle Example" in
> > Tomcat's examples directory with a limited size of (256 MB I think)
> memory
> > resource given to Tomcat. This "Shuffle Example" does not query database
> or
> > does not make complicated operations as you know; it is very simple.
> >
> > Question is, what should I expect? Does it have to respond all requests?
> Or
> > is it normal to throw an exception about "Too many open files" (I use
> NIO
> > connector) and finally OutOfMemoryError and parachute-thing?
> >
> > After I solve this, I can go on to JSF application testing.
> >
> >
> > I couldnt find documents enough about this issue. Can you send me some
> > links?
> >
> > Thanks in advance.
>
> -
> To start a new topic, e-mail: users@tomcat.apache.org
> To unsubscribe, e-mail: [EMAIL PROTECTED]
> For additional commands, e-mail: [EMAIL PROTECTED]
>
>

Re: Tomcat Performance Question

[David Brown]

Hello Ali, please find included below a link URL that addresses the JSF 
performance issue. A much more rigorous test would be to use the JMeter 
distributed testing using the JMeter server. HTH, David.

Ali Ok wrote ..
> Hi,
> 
> We are building a web application with JSF. Last day I tested it with
> JMeter. Results are bad (I guess).
> 
> Then I tried to send 3 requests with JMeter to "Shuffle Example" in
> Tomcat's examples directory with a limited size of (256 MB I think) memory
> resource given to Tomcat. This "Shuffle Example" does not query database or
> does not make complicated operations as you know; it is very simple.
> 
> Question is, what should I expect? Does it have to respond all requests? Or
> is it normal to throw an exception about "Too many open files" (I use NIO
> connector) and finally OutOfMemoryError and parachute-thing?
> 
> After I solve this, I can go on to JSF application testing.
> 
> 
> I couldnt find documents enough about this issue. Can you send me some
> links?
> 
> Thanks in advance.

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Re: Tomcat performance questions

[Christopher Schultz]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Tony,

Tony Anecito wrote:
> Actually I just saw some reports on the new quad intel 45nm
> processors and they are much faster than 15msec.

Yes, but the windows timer resolution sucks. :(

> To justify new hardware and predict scalability Capacity Planning
> groups have to show the before/after performance.

Rather than timing one operation once using nanosecond resolution, try
timing many things many times and then taking the average. I'd bet that
the margin of error gets lost in the noise, anyway.

> I have seen web apps operate in the 4msec range on commercial servlet
> containers.
> 
> I am trying to show a fortune 50 company that Tomcat is fast and a
> viable replacement that can scale. But the commercial product does
> have microsecond resolution in its logs.

Tomcat's performance shouldn't be able to be disproven just because
there are fewer zeros after the 'seconds' decimal point.

> I have measured the System.currentTimeNanos() and found it to be down
> below 1usec execute time so not sure what you are thinking.

You are simply at the mercy of the logger in most cases. Feel free to
write your own logger -- or subclass an existing one and change the
timer display from using System.currentTimeMillis to
System.currentTimeNanos.

- -chris

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Re: Tomcat performance questions

[Filip Hanik - Dev Lists]

Tony Anecito wrote:

Actually I just saw some reports on the new quad intel
45nm processors and they are much faster than 15msec.

To justify new hardware and predict scalability
Capacity Planning groups have to show the before/after
performance.

I have seen web apps operate in the 4msec range on
comercial servlet containers.

I am trying to show a fortune 50 company that Tomcat
is fast and a viable replacement that can scale. But
the commercial product does have microsecond
resolution in its logs.

I have measured the System.currentTimeNanos() and
found it to be down below 1usec execute time so not
sure what you are thinking.
  

http://www.simongbrown.com/blog/2007/08/20/millisecond_accuracy_in_java.html
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6440250

The biggest thing, that seems to be unclearly documented, is what 
System.nanoTime returns and what that value means.
Since that becomes OS/CPU dependent, you must understand the underlying 
value.


You can of course put in any timers you want in Tomcat, just plug in a 
valve or another component that does the measurement for you.

Filip

Hope that helps.

-Tony


--- Filip Hanik - Dev Lists <[EMAIL PROTECTED]>
wrote:

  

Tony Anecito wrote:


Hi All,

I am using Tomcat 6.0.14 with java 1.6.0_02 on
  

Windows


2000 professional.

I am wondering what is the best parser to use for
  

this


configuration? The one with java 1.6.0_02?
  
  

for XML?
the Sun JRE implements the Xerces and Xalan parsers,
so it would be the 
same as if you used those.


Also, what is the best way to monitor performance?
  

I


am using the logs and they are only 15msec
  

resolution.


I am surprised the Tomcat design uses timers with
  

that


resolution even when microsecond resoltion is
advertised. Why not use the nanosecond timers that
were added with jvm 1.5+ ? Please add resolution
  

to


6.0.15.
  
  

 From what I understand
System.currentTimeMillis() - fast
System.currentTimeNanos() - not as fast, and we
don't need that granularity


Regards,
-Tony


 
  


  
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http://www.yahoo.com/r/hs



  

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Re: Tomcat performance questions

[Tony Anecito]

Actually I just saw some reports on the new quad intel
45nm processors and they are much faster than 15msec.

To justify new hardware and predict scalability
Capacity Planning groups have to show the before/after
performance.

I have seen web apps operate in the 4msec range on
comercial servlet containers.

I am trying to show a fortune 50 company that Tomcat
is fast and a viable replacement that can scale. But
the commercial product does have microsecond
resolution in its logs.

I have measured the System.currentTimeNanos() and
found it to be down below 1usec execute time so not
sure what you are thinking.

Hope that helps.

-Tony


--- Filip Hanik - Dev Lists <[EMAIL PROTECTED]>
wrote:

> Tony Anecito wrote:
> > Hi All,
> >
> > I am using Tomcat 6.0.14 with java 1.6.0_02 on
> Windows
> > 2000 professional.
> >
> > I am wondering what is the best parser to use for
> this
> > configuration? The one with java 1.6.0_02?
> >   
> for XML?
> the Sun JRE implements the Xerces and Xalan parsers,
> so it would be the 
> same as if you used those.
> > Also, what is the best way to monitor performance?
> I
> > am using the logs and they are only 15msec
> resolution.
> > I am surprised the Tomcat design uses timers with
> that
> > resolution even when microsecond resoltion is
> > advertised. Why not use the nanosecond timers that
> > were added with jvm 1.5+ ? Please add resolution
> to
> > 6.0.15.
> >   
>  From what I understand
> System.currentTimeMillis() - fast
> System.currentTimeNanos() - not as fast, and we
> don't need that granularity
> > Regards,
> > -Tony
> >
> >
> >  
>

> > Never miss a thing.  Make Yahoo your home page. 
> > http://www.yahoo.com/r/hs
> >
> >
>
-
> > To start a new topic, e-mail:
> users@tomcat.apache.org
> > To unsubscribe, e-mail:
> [EMAIL PROTECTED]
> > For additional commands, e-mail:
> [EMAIL PROTECTED]
> >
> >
> >
> >   
> 
> 
>
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> 



  

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Re: Tomcat performance questions

[Filip Hanik - Dev Lists]

Tony Anecito wrote:

Hi All,

I am using Tomcat 6.0.14 with java 1.6.0_02 on Windows
2000 professional.

I am wondering what is the best parser to use for this
configuration? The one with java 1.6.0_02?
  

for XML?
the Sun JRE implements the Xerces and Xalan parsers, so it would be the 
same as if you used those.

Also, what is the best way to monitor performance? I
am using the logs and they are only 15msec resolution.
I am surprised the Tomcat design uses timers with that
resolution even when microsecond resoltion is
advertised. Why not use the nanosecond timers that
were added with jvm 1.5+ ? Please add resolution to
6.0.15.
  

From what I understand
System.currentTimeMillis() - fast
System.currentTimeNanos() - not as fast, and we don't need that granularity

Regards,
-Tony


  

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http://www.yahoo.com/r/hs


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Re: Tomcat performance measurments...

[Tony Anecito]

Hi Rainer,

Thanks for the well written response and some ideas to
get past the problem.

I agree the 4ms might be latency but until I can
measure at Apache web server or Tomcat more acurately
I will wait to say what it really is.

I am using %D and as you said the timer is not very
accurate. Hopefully I will switch to linux soon and
the whole measurement question will be moot.

Regarding paralallelism to me the best you can
possibly ever get is the response time for a single
request then after that all the measuements just get
worse. But if I can get a transaction under a
microsecond and even if I had only one core then
serially I can do over a million transactions per
second and maybe with two cores 1.5 million per
second.

As I mentioned in another email I just sent one most
my transactions because of the overall design are
under 1500 bytes or 1 ethernet packet.

I will try some of your suggestions and others brought
up by the email group so guess I will be busy tonight.

Thanks,
-Tony


--- Rainer Jung <[EMAIL PROTECTED]> wrote:

> First: measurement:
> 
> Apache access log can use "%D" in the LogFormat,
> which for Apache httpd 
> 2.0 and 2.2 gives microseconds response time.
> Obviously the real 
> resolution depends on the operating system. The
> 15msec you mentioned is 
> way to long for a OS timer resultion.
> 
> mod_jk provides an apache "note" named
> JK_REQUEST_DURATION, which you 
> can include as "%{JK_REQUEST_DURATION}n" again in
> the access log of 
> Apache httpd. This measures Tomcat overall response
> time from the point 
> of view of mod_jk (microseconds formatted as
> seconds.micro).
> 
> Finally Tomcat itself can log milliseconds via "%D"
> in his access log.
> 
> But: when you talk about 4ms transaction time, it's
> more about latency, 
> which is only one aspect of performance. Usually
> latency is only 
> important if it gets to big, but decreasing latency
> below the OK level 
> is not very important. If latency is below an OK
> level, troughput is 
> more important wrt. performance.
> 
> throuput * response time = parallelism
> 
> In general if you want to measure throughput in a
> real life throughput 
> driven system, you need to increase the client
> parallelism to find out 
> how much throughput you can achieve. Response time
> (latency) will go up 
> too, but in some parallelism range, throughput will
> increase more.
> 
> If you add a component like httpd/mod_jk to the
> system, it will increase 
> latency. If your transactions are very fast, the
> added latency might be 
> relatively huge. In terms of throughput this will
> usually not produce a 
> penalty, and in some cases, if you can effectively
> use the features of 
> the added component, throughput might go up.
> 
> Regards,
> 
> Rainer
> 
> Tony Anecito wrote:
> > Hi All,
> > 
> > As I mentioned in my previous email I was able to
> get
> > my system performance using Apache-Tomcat-Jre1.6
> such
> > that I was getting 4msec transaction response
> times.
> > 
> > My problem is I can not tell how much of that
> response
> > time is spent in tomcat versus Apache. I am using
> > windows 2000 where the configuration is Apache -
> > (Tomcat embedded in JBoss 4.2.1) using Mod_jk. The
> > problem I can measure the transaction in the
> servlet
> > which is in the sub-microsecond range but at
> apache
> > access logs or in the mod_jk logs I am seeing
> either 0
> > or 15msec. I suspect that is due to the timers
> used by
> > Apache.
> > I would like to know how long Tomcat is taking for
> the
> > request. I am using web services inside of Tomcat
> so
> > the request goes through that layer.
> > 
> > Also, can anyone tell me the performance
> differences
> > they have see when Tomcat is running on Linux
> versus
> > Windows? I have heard anything between 1 to 30%
> > improvment.
> > 
> > Also, any hints on how to improve Tomcat
> performance
> > appreciated.
> > 
> > Regards,
> > Tony
> 
>
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Re: Tomcat performance measurments...

[Christopher Schultz]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Rainer,

Rainer Jung wrote:
> mod_jk as well as Apache httpd use apr_time_now(). I checked with APR
> 1.2 (httpd 2.2): on Unix/Linux this is gettimeofday().
> 
> Even on an old Solaris 8 system, I can easily get microsecond resolution
> out of a C test program using gettimeofday(), i.e. successive calls to
> gettimeofday return microsecond values differing by 0 or 1 microsecond.

Good to know. IIRC, win32 supports the same call and the API would lead
you to believe that the timer has that accuracy, but the implementation
ends up using a lower-resolution timer and so you always get less
resolution than you'd expect. That may have been a long time ago.

- -chris

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Re: Tomcat performance measurments...

[Tony Anecito]

Hi Martin,

Sorry got busy with all the emails but I thank you for
the time you took to do this and I will read it very
closely and let you know the results if you are
interested.

Thanks everyone for all the helpful comments!

Regards,
Tony Anecito, Founder,
MyUniPortal

--- Martin Gainty <[EMAIL PROTECTED]> wrote:

> Hi Tony-
> 
> *If* you're comfortable with Tomcat serving all your
> content then you
> *could* assign Port 80 to non-SSL HTTP/1.1 Connector
> 
> I found this quite helpful concerning tuning your
> Apache Server
>
http://www.howtoforge.com/configuring_apache_for_maximum_performance
> 
> If you're going to stay with Apache Tomcat
> connectors I found this
> Apache-Tomcat connector readme helpful
> http://tomcat.apache.org/faq/connectors.html
> 
> An article from craig on Apache and Tomcat
> integration (albeit dated from
> 03)
>
http://marc.info/?l=tomcat-user&m=104874913017036&w=2
> 
> Of course benchmarking which seems to be so
> dependent on your environment
> that nobody will publish results without YMMV as
> seen here
> http://www2.linuxjournal.com/article/4752
> 
> This is a TC 5.9 benchmark suggesting 7085
> requests/min on 1.4Ghz 2gb ram
>
http://mail-archives.apache.org/mod_mbox/tomcat-dev/200505.mbox/%3C200505251
> [EMAIL PROTECTED]
> 
> Then again running latest POSIX compliant kernels
> make a BIG difference as
> seen here in this benchmark of POSIX compliant 2.6
> kernel vs 2.4
>
http://www.ibm.com/developerworks/linux/library/l-web26/
> 
> YMMV!
> Martin--
> 
> 
> 
> 
> M--
> - Original Message -
> From: "Tony Anecito" <[EMAIL PROTECTED]>
> To: "Tomcat Users List" 
> Sent: Friday, September 28, 2007 11:15 AM
> Subject: RE: Tomcat performance measurments...
> 
> 
> > I would but I have a web site off of the Apache
> web
> > server and I have the port 80 used by it.
> >
> > -Tony
> >
> > --- Peter Crowther <[EMAIL PROTECTED]>
> > wrote:
> >
> > > > From: Tony Anecito
> [mailto:[EMAIL PROTECTED]
> > > > Also, any hints on how to improve Tomcat
> > > performance
> > > > appreciated.
> > >
> > > Why not do the easy one - get rid of that extra
> > > layer of
> > > performance-sapping httpd and mod_jk in the
> middle
> > > instead?
> > >
> > > - Peter
> > >
> > >
> >
>
-
> > > To start a new topic, e-mail:
> > > users@tomcat.apache.org
> > > To unsubscribe, e-mail:
> > > [EMAIL PROTECTED]
> > > For additional commands, e-mail:
> > > [EMAIL PROTECTED]
> > >
> > >
> >
> >
> >
> >
> >
>

> 
> > Looking for a deal? Find great prices on flights
> and hotels with Yahoo!
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> > http://farechase.yahoo.com/
> >
> >
>
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> > To start a new topic, e-mail:
> users@tomcat.apache.org
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> >
> >
> 
> 
>
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Re: Tomcat performance measurments...

[Martin Gainty]

Hi Tony-

*If* you're comfortable with Tomcat serving all your content then you
*could* assign Port 80 to non-SSL HTTP/1.1 Connector

I found this quite helpful concerning tuning your Apache Server
http://www.howtoforge.com/configuring_apache_for_maximum_performance

If you're going to stay with Apache Tomcat connectors I found this
Apache-Tomcat connector readme helpful
http://tomcat.apache.org/faq/connectors.html

An article from craig on Apache and Tomcat integration (albeit dated from
03)
http://marc.info/?l=tomcat-user&m=104874913017036&w=2

Of course benchmarking which seems to be so dependent on your environment
that nobody will publish results without YMMV as seen here
http://www2.linuxjournal.com/article/4752

This is a TC 5.9 benchmark suggesting 7085 requests/min on 1.4Ghz 2gb ram
http://mail-archives.apache.org/mod_mbox/tomcat-dev/200505.mbox/%3C200505251
[EMAIL PROTECTED]

Then again running latest POSIX compliant kernels make a BIG difference as
seen here in this benchmark of POSIX compliant 2.6 kernel vs 2.4
http://www.ibm.com/developerworks/linux/library/l-web26/

YMMV!
Martin--




M--
- Original Message -
From: "Tony Anecito" <[EMAIL PROTECTED]>
To: "Tomcat Users List" 
Sent: Friday, September 28, 2007 11:15 AM
Subject: RE: Tomcat performance measurments...


> I would but I have a web site off of the Apache web
> server and I have the port 80 used by it.
>
> -Tony
>
> --- Peter Crowther <[EMAIL PROTECTED]>
> wrote:
>
> > > From: Tony Anecito [mailto:[EMAIL PROTECTED]
> > > Also, any hints on how to improve Tomcat
> > performance
> > > appreciated.
> >
> > Why not do the easy one - get rid of that extra
> > layer of
> > performance-sapping httpd and mod_jk in the middle
> > instead?
> >
> > - Peter
> >
> >
> -
> > To start a new topic, e-mail:
> > users@tomcat.apache.org
> > To unsubscribe, e-mail:
> > [EMAIL PROTECTED]
> > For additional commands, e-mail:
> > [EMAIL PROTECTED]
> >
> >
>
>
>
>
>


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Re: Tomcat performance measurments...

[Rainer Jung]

Tony Anecito wrote:

Hi Rainer,

I am using Windows 2000 professional so I suspect
Tomcat is using an windows api call that is limited to
15msec resolution even though the %d is advertised as
microsecond resolution.


You are right:

http://blogs.msdn.com/embedded/archive/2006/02/20/535792.aspx

On Windows APR uses GetSystemTimeAsFileTime, which only has a 15ms 
resolution on x86, although the data structures could store a 100ns 
resolution.


Wrong platform for fine grained investigations.

Regards,

Rainer

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Re: Tomcat performance measurments...

[Tony Anecito]

Hi Rainer,

I am using Windows 2000 professional so I suspect
Tomcat is using an windows api call that is limited to
15msec resolution even though the %d is advertised as
microsecond resolution.

The Java jre had this issue then with release 1.5+ Sun
added a nanosecond timer which is what I used for
making servlet measurments. Of course when I got below
that in my design/implementation that was not good
enough but by then I figured that kind of response
time meant over 1 billion requests per second per cpu
so I was happy. Of course getting that out of the
servlet container and web services layer was the next
challenge ;)

Regards,
Tony Anecito
Founder, MyUniPortal

--- Rainer Jung <[EMAIL PROTECTED]> wrote:

> Christopher Schultz wrote:
> > Other factors include the resolution of the timer
> being used by Apache
> > and/or mod_jk for emitting log messages. Most
> people don't care about
> > high-resolution timing for things like web server
> logs, so I wouldn't
> > expect Apache to be using one.
> 
> mod_jk as well as Apache httpd use apr_time_now(). I
> checked with APR 
> 1.2 (httpd 2.2): on Unix/Linux this is
> gettimeofday().
> 
> Even on an old Solaris 8 system, I can easily get
> microsecond resolution 
> out of a C test program using gettimeofday(), i.e.
> successive calls to 
> gettimeofday return microsecond values differing by
> 0 or 1 microsecond.
> 
> Regards,
> 
> Rainer
> 
>
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> users@tomcat.apache.org
> To unsubscribe, e-mail:
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> [EMAIL PROTECTED]
> 
> 



  

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Re: Tomcat performance measurments...

[Rainer Jung]

Christopher Schultz wrote:

Other factors include the resolution of the timer being used by Apache
and/or mod_jk for emitting log messages. Most people don't care about
high-resolution timing for things like web server logs, so I wouldn't
expect Apache to be using one.


mod_jk as well as Apache httpd use apr_time_now(). I checked with APR 
1.2 (httpd 2.2): on Unix/Linux this is gettimeofday().


Even on an old Solaris 8 system, I can easily get microsecond resolution 
out of a C test program using gettimeofday(), i.e. successive calls to 
gettimeofday return microsecond values differing by 0 or 1 microsecond.


Regards,

Rainer

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Re: Tomcat performance measurments...

[Tony Anecito]

Hi Chris,

Yes, I am doing my measurements in a controlled
environment. As for measurments I have gone as far as
using a sniffer for looking at the tcp/ip
conversations.

I understand about the timers for Apache but as
hardware and the servlet containers (and jvms) get
faster the old timers become obsolete from my
perspective especially as companies want to shrink
thier data centers the metrics of how web and app
servers are doing become more important. CPU
utilization need to be complemented by response time
measurements for services. 

The faster the web and/or app server is the more
clients it can handle without adding hardware. Other
app server commercial products are starting to make a
big deal out of real-time responses (millisecond or
microsecond) when open source does not seem to even
able to tell you how good they are and I am trying to
prove that with open source and cheap hardware why buy
commercial grade? But to do that I need to prove it
not only in a controlled environment but the admins
need to see that in their logs to tell thier boss.

Does that help?

Thanks,
-Tony
 

--- Christopher Schultz <[EMAIL PROTECTED]>
wrote:

> -BEGIN PGP SIGNED MESSAGE-
> Hash: SHA1
> 
> Tony,
> 
> Tony Anecito wrote:
> > I would but I have a web site off of the Apache
> web
> > server and I have the port 80 used by it.
> 
> So? If you're doing performance testing, you should
> be doing it in a
> laboratory environment. You /are/ doing this on a
> test server, not
> product, right?
> 
> You should be able to disable one of your servers
> for testing.
> 
> Other factors include the resolution of the timer
> being used by Apache
> and/or mod_jk for emitting log messages. Most people
> don't care about
> high-resolution timing for things like web server
> logs, so I wouldn't
> expect Apache to be using one.
> 
> Another option would be to write a trivial servlet
> that always does
> nothing and returns nothing, and then time your
> requests through that.
> You should be able to tell what communication
> overhead is being added by
> Apache httpd and mod_jk.
> 
> - -chris
> 
> -BEGIN PGP SIGNATURE-
> Version: GnuPG v1.4.7 (MingW32)
> Comment: Using GnuPG with Mozilla -
> http://enigmail.mozdev.org
> 
>
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> oReh/Xh7XwyZLBFUDcpBEJ0=
> =bkxT
> -END PGP SIGNATURE-
> 
>
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Re: Tomcat performance measurments...

[Rainer Jung]

First: measurement:

Apache access log can use "%D" in the LogFormat, which for Apache httpd 
2.0 and 2.2 gives microseconds response time. Obviously the real 
resolution depends on the operating system. The 15msec you mentioned is 
way to long for a OS timer resultion.


mod_jk provides an apache "note" named JK_REQUEST_DURATION, which you 
can include as "%{JK_REQUEST_DURATION}n" again in the access log of 
Apache httpd. This measures Tomcat overall response time from the point 
of view of mod_jk (microseconds formatted as seconds.micro).


Finally Tomcat itself can log milliseconds via "%D" in his access log.

But: when you talk about 4ms transaction time, it's more about latency, 
which is only one aspect of performance. Usually latency is only 
important if it gets to big, but decreasing latency below the OK level 
is not very important. If latency is below an OK level, troughput is 
more important wrt. performance.


throuput * response time = parallelism

In general if you want to measure throughput in a real life throughput 
driven system, you need to increase the client parallelism to find out 
how much throughput you can achieve. Response time (latency) will go up 
too, but in some parallelism range, throughput will increase more.


If you add a component like httpd/mod_jk to the system, it will increase 
latency. If your transactions are very fast, the added latency might be 
relatively huge. In terms of throughput this will usually not produce a 
penalty, and in some cases, if you can effectively use the features of 
the added component, throughput might go up.


Regards,

Rainer

Tony Anecito wrote:

Hi All,

As I mentioned in my previous email I was able to get
my system performance using Apache-Tomcat-Jre1.6 such
that I was getting 4msec transaction response times.

My problem is I can not tell how much of that response
time is spent in tomcat versus Apache. I am using
windows 2000 where the configuration is Apache -
(Tomcat embedded in JBoss 4.2.1) using Mod_jk. The
problem I can measure the transaction in the servlet
which is in the sub-microsecond range but at apache
access logs or in the mod_jk logs I am seeing either 0
or 15msec. I suspect that is due to the timers used by
Apache.
I would like to know how long Tomcat is taking for the
request. I am using web services inside of Tomcat so
the request goes through that layer.

Also, can anyone tell me the performance differences
they have see when Tomcat is running on Linux versus
Windows? I have heard anything between 1 to 30%
improvment.

Also, any hints on how to improve Tomcat performance
appreciated.

Regards,
Tony


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Re: Tomcat performance measurments...

[Christopher Schultz]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Tony,

Tony Anecito wrote:
> I would but I have a web site off of the Apache web
> server and I have the port 80 used by it.

So? If you're doing performance testing, you should be doing it in a
laboratory environment. You /are/ doing this on a test server, not
product, right?

You should be able to disable one of your servers for testing.

Other factors include the resolution of the timer being used by Apache
and/or mod_jk for emitting log messages. Most people don't care about
high-resolution timing for things like web server logs, so I wouldn't
expect Apache to be using one.

Another option would be to write a trivial servlet that always does
nothing and returns nothing, and then time your requests through that.
You should be able to tell what communication overhead is being added by
Apache httpd and mod_jk.

- -chris

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RE: Tomcat performance measurments...

[Tony Anecito]

I would but I have a web site off of the Apache web
server and I have the port 80 used by it.

-Tony

--- Peter Crowther <[EMAIL PROTECTED]>
wrote:

> > From: Tony Anecito [mailto:[EMAIL PROTECTED] 
> > Also, any hints on how to improve Tomcat
> performance
> > appreciated.
> 
> Why not do the easy one - get rid of that extra
> layer of
> performance-sapping httpd and mod_jk in the middle
> instead?
> 
>   - Peter
> 
>
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> To start a new topic, e-mail:
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> 



   

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RE: Tomcat performance measurments...

[Peter Crowther]

> From: Tony Anecito [mailto:[EMAIL PROTECTED] 
> Also, any hints on how to improve Tomcat performance
> appreciated.

Why not do the easy one - get rid of that extra layer of
performance-sapping httpd and mod_jk in the middle instead?

- Peter

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Re: tomcat performance on static content over SSL/non-SSL

[Christopher Schultz]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Leon,

Leon Rosenberg wrote:
> security by obscurity, that is.

Through I agree that claiming Apache httpd increases security, it is
certainly not security by obscurity. It is another layer between the
attacker and the goodies. You may disagree about the efficacy of that
layer, but it's not merely obscurity.

Changing your web server's "Server" header response to "MS ISS" would be
security-by-obscurity. ;)

- -chris

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Re: tomcat performance on static content over SSL/non-SSL

[Matthew Kerle]

doh! load-balancing of course...

I don't know, I'm a stickler for the old "do one thing, do it well", 
tomcat rocks at serving dynamic java, apache rocks at being internet 
facing serving static & CGI. the jk connector is good & solid, so I'm 
happy to keep everything separate and only have tomcat serving dynamic 
pages. plus that way if you ever run into scalability problems you have 
the infrastructure to scale right there!


* Matthew Kerle
* * IT Consultant *
* Canberra, Australia*

Mobile: +61404 096 863
Email: Matthew Kerle 
Web:  Matthew Kerle 


Christopher Schultz wrote:

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Matt,

Matthew Kerle wrote:
  

Apart from integration into a larger site or static content, when would
you put httpd in front of tomcat?



This might count as "integrating into a larger site", but I use Apache
httpd to front multiple instances of Tomcat through a single port number
(by mapping webapps individually through mod_jk). This allows me to
start and stop a single webapp, upgrade the JVM and/or Tomcat running
it, and then bring it back up again without disturbing the other
applications.

- -chris



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Re: tomcat performance on static content over SSL/non-SSL

[Matthew Kerle]

good security is hard.

I've seen state governments using the reverse-proxy layered approach 
described below, and that worked extremely well. I've also seen a 
federal government with an open database port to the internet (won't say 
which! lets just say they're not known for prompt security fixes...), 
but who won't allow a proxied http tunnel inside for security reasons. 
just crazy, talk about take the log out of your own eye...


The only *really* safe option (against internal compromise) I've seen is 
to replicate databases into the DMZ, and disallow all connections from 
the DMZ to internal. But then you have problems with replication, and if 
you database is compromised then you risk data exposure. Which means 
there is no final solution, but it helps to raise the difficulty for 
attackers and minimise your risk. then make sure your backups work!!!


cheers.

* Matthew Kerle
* * IT Consultant *
* Canberra, Australia*

Mobile: +61404 096 863
Email: Matthew Kerle 
Web:  Matthew Kerle 


Leon Rosenberg wrote:

security by obscurity, that is.

since the httpd just sends all requests further to the tomcat, if
there is a security relevant bug in tomcat code, it would be accessed
by the remote side either way. Further, are your machines, on which
httpd is running, running under different OS than your tomcat
machines? Cause if they are the same, the same security issue would be
present on both, so the attacker could easily reach the tomcat machine
from the httpd machine via the same hole once he's there.

It sounds like a good idea to put a firewall between tomcat and a db.
But your tomcat machine and your webapp will have to access the db
somehow, so why shouldn't the attacker use the same method to access
your db, once he's on the tomcat machine?

Therefore, your security infrastructure sounds like a good idea, but
in fact it doesn't add any security. Just put a decent firewall
between the internet and your cluster and that is it. Once its passed
your security infrastructure wouldn't prevent the attacker to go on
further.

just 2 cents.

leon

P.S. Btw, some (recently fixed) buffer overflows in mod_jk connector
(and in httpd itself) will actually reduce your security, since httpd
is far less secure than java.

On 8/15/07, Lizak, Ed <[EMAIL PROTECTED]> wrote:
  

We use httpd to sit in between firewalls and handle all incoming traffic.
Static content is served from there and dynamic content is proxied through
to the Tomcat server behind another firewall.  SSL is only needed from the
client to the httpd server.

The Tomcat server then handles the database access which passes through
another firewall to hit our internal network where the database lives.

I'm not a security expert but it seems like a good idea having your database
connections far removed from the Internet connection.  At the very least it
would seem you would have to have multiple layers of server compromised
before any data is exposed.

Is this not a good reason to use httpd in front of Tomcat?

-EJL

---


Matt,

Matthew Kerle wrote:


Apart from integration into a larger site or static content, when would
you put httpd in front of tomcat?
  

This might count as "integrating into a larger site", but I use Apache
httpd to front multiple instances of Tomcat through a single port number
(by mapping webapps individually through mod_jk). This allows me to
start and stop a single webapp, upgrade the JVM and/or Tomcat running
it, and then bring it back up again without disturbing the other
applications.

- -chris

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--

Re: tomcat performance on static content over SSL/non-SSL

[Leon Rosenberg]

security by obscurity, that is.

since the httpd just sends all requests further to the tomcat, if
there is a security relevant bug in tomcat code, it would be accessed
by the remote side either way. Further, are your machines, on which
httpd is running, running under different OS than your tomcat
machines? Cause if they are the same, the same security issue would be
present on both, so the attacker could easily reach the tomcat machine
from the httpd machine via the same hole once he's there.

It sounds like a good idea to put a firewall between tomcat and a db.
But your tomcat machine and your webapp will have to access the db
somehow, so why shouldn't the attacker use the same method to access
your db, once he's on the tomcat machine?

Therefore, your security infrastructure sounds like a good idea, but
in fact it doesn't add any security. Just put a decent firewall
between the internet and your cluster and that is it. Once its passed
your security infrastructure wouldn't prevent the attacker to go on
further.

just 2 cents.

leon

P.S. Btw, some (recently fixed) buffer overflows in mod_jk connector
(and in httpd itself) will actually reduce your security, since httpd
is far less secure than java.

On 8/15/07, Lizak, Ed <[EMAIL PROTECTED]> wrote:
> We use httpd to sit in between firewalls and handle all incoming traffic.
> Static content is served from there and dynamic content is proxied through
> to the Tomcat server behind another firewall.  SSL is only needed from the
> client to the httpd server.
>
> The Tomcat server then handles the database access which passes through
> another firewall to hit our internal network where the database lives.
>
> I'm not a security expert but it seems like a good idea having your database
> connections far removed from the Internet connection.  At the very least it
> would seem you would have to have multiple layers of server compromised
> before any data is exposed.
>
> Is this not a good reason to use httpd in front of Tomcat?
>
> -EJL
>
> ---
>
>
> Matt,
>
> Matthew Kerle wrote:
> > Apart from integration into a larger site or static content, when would
> > you put httpd in front of tomcat?
>
> This might count as "integrating into a larger site", but I use Apache
> httpd to front multiple instances of Tomcat through a single port number
> (by mapping webapps individually through mod_jk). This allows me to
> start and stop a single webapp, upgrade the JVM and/or Tomcat running
> it, and then bring it back up again without disturbing the other
> applications.
>
> - -chris
>
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> Version: GnuPG v1.4.7 (MingW32)
> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
>
> iD8DBQFGww/r9CaO5/Lv0PARAihDAKCWoVVHxQF0hCTiIsgFLC0bjMrYyACaAvfr
> sn1AKYvbLyk3Bbap+tyIrsE=
> =Zlq+
> -END PGP SIGNATURE-
>
>
> IMPORTANT CONFIDENTIALITY NOTICE:This document, and any documents
> accompanying this transmission, contains confidential, legally protected
> information and is intended only for the person or entity to which it is
> addressed. If you are not the intended recipient, any disclosure, copying,
> distribution or the taking of any action in reliance on the contents of this
> transmission is strictly prohibited. If you receive this transmission in
> error, please contact the sender and delete or destroy the
> material/information.
> Corporate Headquarters <> 10340 Evendale Dr. <> Cincinnati, OH 45241 <>
> 513.563.1400
>
> -
> To start a new topic, e-mail: users@tomcat.apache.org
> To unsubscribe, e-mail: [EMAIL PROTECTED]
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RE: tomcat performance on static content over SSL/non-SSL

[Lizak, Ed]

We use httpd to sit in between firewalls and handle all incoming traffic.
Static content is served from there and dynamic content is proxied through
to the Tomcat server behind another firewall.  SSL is only needed from the
client to the httpd server.

The Tomcat server then handles the database access which passes through
another firewall to hit our internal network where the database lives.

I'm not a security expert but it seems like a good idea having your database
connections far removed from the Internet connection.  At the very least it
would seem you would have to have multiple layers of server compromised
before any data is exposed.

Is this not a good reason to use httpd in front of Tomcat?

-EJL

---


Matt,

Matthew Kerle wrote:
> Apart from integration into a larger site or static content, when would
> you put httpd in front of tomcat?

This might count as "integrating into a larger site", but I use Apache
httpd to front multiple instances of Tomcat through a single port number
(by mapping webapps individually through mod_jk). This allows me to
start and stop a single webapp, upgrade the JVM and/or Tomcat running
it, and then bring it back up again without disturbing the other
applications.

- -chris

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=Zlq+
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IMPORTANT CONFIDENTIALITY NOTICE:This document, and any documents
accompanying this transmission, contains confidential, legally protected
information and is intended only for the person or entity to which it is
addressed. If you are not the intended recipient, any disclosure, copying,
distribution or the taking of any action in reliance on the contents of this
transmission is strictly prohibited. If you receive this transmission in
error, please contact the sender and delete or destroy the
material/information.
Corporate Headquarters <> 10340 Evendale Dr. <> Cincinnati, OH 45241 <>
513.563.1400 

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Re: tomcat performance on static content over SSL/non-SSL

[Christopher Schultz]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Matt,

Matthew Kerle wrote:
> Apart from integration into a larger site or static content, when would
> you put httpd in front of tomcat?

This might count as "integrating into a larger site", but I use Apache
httpd to front multiple instances of Tomcat through a single port number
(by mapping webapps individually through mod_jk). This allows me to
start and stop a single webapp, upgrade the JVM and/or Tomcat running
it, and then bring it back up again without disturbing the other
applications.

- -chris

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Re: Tomcat Performance Concerns

[David Rees]

On 11/21/06, Andre Prasetya <[EMAIL PROTECTED]> wrote:

On 11/21/06, Harry <[EMAIL PROTECTED]> wrote:
> PostgreSQL is excellent, IMHO - fast, and easy to administrate.
Yupe agreed, but for database that is used with frequent insert and delete
statement, I have to vacuum them frequently. Which is a boring task to do. I
created an agent that will vacuum the database every friday. Then I move it
to MySql because I think its more suited to my needs.


PostgreSQL has had autovacuum integrated into version 8.1 and newer
(released almost a year ago now), so saying you need to autovacuum is
no longer an argument against using Postgres.

-Dave

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Re: Tomcat Performance Concerns

[Andre Prasetya]

Yupe agreed, but for database that is used with frequent insert and delete
statement, I have to vacuum them frequently. Which is a boring task to do. I
created an agent that will vacuum the database every friday. Then I move it
to MySql because I think its more suited to my needs.

-Andre-

On 11/21/06, Harry <[EMAIL PROTECTED]> wrote:


> systems, but rather than start a flame war, I'll say that just for
> completeness you should probably look into postgresql and firebird or
> one of their object-oriented cousins like db4o (dual licenced, if I'm
> not mistaking).

PostgreSQL is excellent, IMHO - fast, and easy to administrate.

Harry Mantheakis


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--
-Andre-

PCs are like air conditioner, if you open Windows, they don't work

Re: Tomcat Performance Concerns

[Tomi NA]

2006/11/19, Gaurav Kushwaha <[EMAIL PROTECTED]>:

Thanks Martin and Everyone else for the suggestions.
Martin, Oracle I dont want to go with since its expensive. I will infact try
out MySQL and will let you guys know.


I would argue that you chose one of the inferior database management
systems, but rather than start a flame war, I'll say that just for
completeness you should probably look into postgresql and firebird or
one of their object-oriented cousins like db4o (dual licenced, if I'm
not mistaking).
A lot more could be said on the topic, but this is a much, much better
start than the initial extreme...well, extremes (Access and Oracle).

Cheers,
t.n.a.

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