Re: Apache -> Tomcat connection problem
On Thu, Feb 26, 2009 at 6:45 PM, Rainer Jung wrote: > All problems described starting with comment #9 have been fixed by Rüdiger > latest in revision 396050. Version 2.2.2 is revision 396066 so should > include those fixes. > > This is starting to look more like an Apache issue, maybe I should move to >> that list... >> > > I think that's appropriate, but don't be astonished in case someone > suggests updating ;) > Rainer, just an update: I changed my httpd.conf ProxyPass directives like so: ProxyPass /foo ajp://localhost:8009/foo/ ttl=600 and my Tomcat connector like this: So basically, specifying what are the documented defaults plus adding the connectionTimeout. Now the connections build up, drop down a little, build back up, etc. It goes over 300 (150) from time to time but never goes high enough (350) to trigger a graceful restart. So the system is stable though not behaving the way I think it should. Not sure which part made the difference. I haven't gotten to trying worker MPM yet. I tried dropping ttl to 300 with no apparent difference in behavior. Thanks for your help. -- Daryl Stultz _ 6 Degrees Software and Consulting, Inc. http://www.6degrees.com mailto:da...@6degrees.com
Re: Apache -> Tomcat connection problem
On 26.02.2009 22:35, Daryl Stultz wrote: It appears my last post didn't make it through some virus scanner (Antigen for Exchange found Body of Message infected with Exceeded Realtime Timeout virus.) Apologies if it made it to the list. On Tue, Feb 24, 2009 at 7:40 PM, Rainer Jungwrote: smaxEither 0 or 1. I would say 0 in order to get rid of idle connections. This is ignored for 2.2.2 (see https://issues.apache.org/bugzilla/show_bug.cgi?id=43371). So fixed in 2.2.10. connectiontimeout E.g. 5 or 10 This produces an error: ProxyPass unknown Worker parameter. Added in 2.2.10. Unfortunately, I'm not in a position to upgrade httpd as you recommend. Many of the interesting proxy enhancements for httpd 2.x came with 2.2 and there were a couple of additions and fixes during the 2.2 releases. So if you want to use proxy with balancing or with more detailed pool configuration, you need to be able to upgrade httpd to a recent patch level, this time and maybe again in the future. Should I try the worker MPM? I found this which suggests a bug has been fixed for worker MPM: https://issues.apache.org/bugzilla/show_bug.cgi?id=38227#c9 This is a link right to James Robinson's description of his problem which seems pretty consistent with mine. Odd, though, the original poster switched from worker to prefork as a workaround and I'm considering the opposite, so probably not the solution for me. Comments? All problems described starting with comment #9 have been fixed by Rüdiger latest in revision 396050. Version 2.2.2 is revision 396066 so should include those fixes. This is starting to look more like an Apache issue, maybe I should move to that list... I think that's appropriate, but don't be astonished in case someone suggests updating ;) Regards, Rainer - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Apache -> Tomcat connection problem
It appears my last post didn't make it through some virus scanner (Antigen for Exchange found Body of Message infected with Exceeded Realtime Timeout virus.) Apologies if it made it to the list. On Tue, Feb 24, 2009 at 7:40 PM, Rainer Jung wrote: > > smaxEither 0 or 1. I would say 0 in order to get rid of idle > connections. > This is ignored for 2.2.2 (see https://issues.apache.org/bugzilla/show_bug.cgi?id=43371). > > connectiontimeout E.g. 5 or 10 This produces an error: ProxyPass unknown Worker parameter. Unfortunately, I'm not in a position to upgrade httpd as you recommend. Should I try the worker MPM? I found this which suggests a bug has been fixed for worker MPM: https://issues.apache.org/bugzilla/show_bug.cgi?id=38227#c9 This is a link right to James Robinson's description of his problem which seems pretty consistent with mine. Odd, though, the original poster switched from worker to prefork as a workaround and I'm considering the opposite, so probably not the solution for me. Comments? This is starting to look more like an Apache issue, maybe I should move to that list... -- Daryl Stultz _ 6 Degrees Software and Consulting, Inc. http://www.6degrees.com mailto:da...@6degrees.com
Re: Apache -> Tomcat connection problem
On Tue, Feb 24, 2009 at 7:40 PM, Rainer Jung wrote: > > smaxEither 0 or 1. I would say 0 in order to get rid of idle > connections. > This is ignored for 2.2.2 (see https://issues.apache.org/bugzilla/show_bug.cgi?id=43371). > > connectiontimeout E.g. 5 or 10 This produces an error: ProxyPass unknown Worker parameter. Unfortunately, I'm not in a position to upgrade httpd as you recommend. Should I try the worker MPM? I found this which suggests a bug has been fixed for worker MPM: https://issues.apache.org/bugzilla/show_bug.cgi?id=38227#c9 This is a link right to James Robinson's description of his problem which seems pretty consistent with mine. Odd, though, the original poster switched from worker to prefork as a workaround and I'm considering the opposite, so probably not the solution for me. Comments? This is starting to look more like an Apache issue, maybe I should move to that list... -- Daryl Stultz _ 6 Degrees Software and Consulting, Inc. http://www.6degrees.com mailto:da...@6degrees.com
Re: Apache -> Tomcat connection problem
On 24.02.2009 23:31, Daryl Stultz wrote: Tomcat AJP connector defaults to 200 for maxThreads. The site has 20 Defaults? I think no, and you haven't configured 200 in your abive config snippet. See Christopher's response. Do you know of the implementation being different than the docs? No, he's right, but the sizing of the thread pool is so important that I wouldn't only rely on the default. You always have to remember that and it might change during upgrading or when switching to a different connector implementation. First check, whether it is really ESTABISHED connections. Then configure reasonable timeouts as described in the mod_proxy documentation and an additional connectionTimeout for Tomcat. This is the part where expert advice comes in. I don't have any idea what "reasonable timeouts" are and the docs don't give a decent way to calculate it. My personal opinion: min Default 0 is fine. max Default 1 is fine for prefork MPM (single threaded) smaxEither 0 or 1. I would say 0 in order to get rid of idle connections. acquire Should be irrelevant for prefork. connectiontimeout E.g. 5 or 10 pingI would activate this with a value of e.g. 10 (seconds) ttl E.g. 600 (seconds). You should then set connectionTimeout on your Tomcat connector to 60 (milliseconds). timeout Setting a timeout generally would make things more robust, but you need to make sure, that nothing in your webapp responds slower than this value (seconds). Regards, Rainer - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Apache -> Tomcat connection problem
On Tue, Feb 24, 2009 at 4:56 PM, Rainer Jung wrote: > You need to understand it. > ... > You can check your MPM by calling "httpd -V". The output will contain a > line like > > -D APACHE_MPM_DIR="server/mpm/worker" > Server version: Apache/2.2.2 Server built: Jul 26 2006 11:12:08 Server's Module Magic Number: 20051115:2 Server loaded: APR 1.2.2, APR-Util 1.2.7 Compiled using: APR 1.2.2, APR-Util 1.2.7 Architecture: 32-bit Server MPM: Prefork threaded: no forked: yes (variable process count) Server compiled with -D APACHE_MPM_DIR="server/mpm/prefork" > > Tomcat AJP connector defaults to 200 for maxThreads. The site has 20 >> > > Defaults? I think no, and you haven't configured 200 in your abive config > snippet. > See Christopher's response. Do you know of the implementation being different than the docs? > > > applications, each with 2 ProxyPass directives for ports 80 and 443. The >> > > Hmm, not sure, how ports 80 and 443 with HTTP(s) proxying come into play > now. > Me neither, just trying to provide useful setup information. I have a total of about 40 ProxyPass (mod_proxy_ajp) directives. I don't have any idea how that impacts things. > > What's you platform? Fedora Core release 5 (Bordeaux) > > The command counts LISTEN (the listening socket), the 2 header lines, all > ESTABLISHED connections (those are the ones you are after) and e.g. also > TIME_WAIT connections, all of them together. You need to count more > specific. > Yes, I mentally accounted for the header lines. Leaving off the wc -l, I have never seen anything but ESTABLISHED. I'll keep an eye on it. > > Consider upgrading httpd to 2.2.11, because mod_proxy_ajp was very new in > 2.2.2 and there have been a couple of fixes after that version. > I'll look into that. > First check, whether it is really ESTABISHED connections. Then configure > reasonable timeouts as described in the mod_proxy documentation and an > additional connectionTimeout for Tomcat. > This is the part where expert advice comes in. I don't have any idea what "reasonable timeouts" are and the docs don't give a decent way to calculate it. Thanks. -- Daryl Stultz _ 6 Degrees Software and Consulting, Inc. http://www.6degrees.com mailto:da...@6degrees.com
Re: Apache -> Tomcat connection problem
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Rainer, On 2/24/2009 4:56 PM, Rainer Jung wrote: > On 24.02.2009 21:50, Daryl Stultz wrote: >> Tomcat AJP connector defaults to 200 for maxThreads. The site has 20 > > Defaults? I think no, and you haven't configured 200 in your abive > config snippet. Maybe there is no default, but it is sure documented as such: http://tomcat.apache.org/tomcat-5.5-doc/config/ajp.html Docs for 'maxThreads' attribute: " The maximum number of request processing threads to be created by this Connector, which therefore determines the maximum number of simultaneous requests that can be handled. If not specified, this attribute is set to 200. " - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkmkbzYACgkQ9CaO5/Lv0PDXxgCgoxfcryiulllcC1AsSZYbS0ZJ r1gAnjJCWj45D0Yot5sGCLa6ZnUtto3k =RM2B -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Apache -> Tomcat connection problem
On 24.02.2009 21:50, Daryl Stultz wrote: I'm running Tomcat 5.5.17 behind Apache 2.2.2. I am connecting with a Tomcat AJP connector like so: and Apache ProxyPass like so: ProxyPass /myapp ajp://localhost:8009/myapp/ Apache has the default number of connections set - MaxClients is either 256 or 150, I don't understand the prefork/worker MPM thing. As above, the You need to understand it. prefork MPM: only uses processes, not multiple threads per process. Each request being processed occupies one process. Each process can only handle one rquest at a time. Scaling up and down via creating additional processes or stopping idle ones. worker MPM: Uses multi-threaded processes, each with the same number of (configured) threads, by default 25. Each request being processed occupies one thread, each process can handle multiple threads concurrently (as many as you configured threads per process). Scaling up and down via creating additional processes or stopping idle ones. winnt MPM: Only on windows. Uses two processes, one is a watchdog (it does also exist for prefork and worker) and the other one is highly multithreaded (default 150 threads) and does all the requests. Like worker with one fixed worker process using much more threads in this process. No scaling up and down. You can check your MPM by calling "httpd -V". The output will contain a line like -D APACHE_MPM_DIR="server/mpm/worker" Tomcat AJP connector defaults to 200 for maxThreads. The site has 20 Defaults? I think no, and you haven't configured 200 in your abive config snippet. applications, each with 2 ProxyPass directives for ports 80 and 443. The Hmm, not sure, how ports 80 and 443 with HTTP(s) proxying come into play now. general load on the site is low with 5 - 15 users on at any one time. This command here, I believe, counts the number of connections between Apache and Tomcat: netstat -tn | sed -n -e| wc -l What's you platform? The command counts LISTEN (the listening socket), the 2 header lines, all ESTABLISHED connections (those are the ones you are after) and e.g. also TIME_WAIT connections, all of them together. You need to count more specific. Depending on your idle timeouts on the AJP connections, you might have many more TIME_WAITs than ESTABLISHED. For the idle timeouts, see the mod_proxy docs page for httpd and connectionTimeout for the Tomcat AJP connector. Consider upgrading httpd to 2.2.11, because mod_proxy_ajp was very new in 2.2.2 and there have been a couple of fixes after that version. The site has been running for a couple years, though the code changes and I continue to add new apps, it has been running fine. Now what seems to be happening is the number of connections between Apache and Tomcat grows at various rates from 4 or 10 or 20 after an Apache restart to 400 and more. At around 400 the site gets very sluggish. This seems to make some sense if Tomcat has maxThreads of 200 and the above command counts connections in both directions - TC is running out of connections. The question is why? I don't have enough users to warrant the connection pool growing like this. I currently have a cron task that does a graceful restart of Apache after 300 connections. Can anyone shed some light on this or point me to some other resource for help? First check, whether it is really ESTABISHED connections. Then configure reasonable timeouts as described in the mod_proxy documentation and an additional connectionTimeout for Tomcat. Regards, Rainer - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Apache -> Tomcat connection problem
Hello, I don't know if this is an Apache problem, Tomcat problem, both or neither. Hopefully someone can point me in the right direction. I'm running Tomcat 5.5.17 behind Apache 2.2.2. I am connecting with a Tomcat AJP connector like so: and Apache ProxyPass like so: ProxyPass /myapp ajp://localhost:8009/myapp/ Apache has the default number of connections set - MaxClients is either 256 or 150, I don't understand the prefork/worker MPM thing. As above, the Tomcat AJP connector defaults to 200 for maxThreads. The site has 20 applications, each with 2 ProxyPass directives for ports 80 and 443. The general load on the site is low with 5 - 15 users on at any one time. This command here, I believe, counts the number of connections between Apache and Tomcat: netstat -tn | sed -n -e '1,2p;/8009/p' | wc -l The site has been running for a couple years, though the code changes and I continue to add new apps, it has been running fine. Now what seems to be happening is the number of connections between Apache and Tomcat grows at various rates from 4 or 10 or 20 after an Apache restart to 400 and more. At around 400 the site gets very sluggish. This seems to make some sense if Tomcat has maxThreads of 200 and the above command counts connections in both directions - TC is running out of connections. The question is why? I don't have enough users to warrant the connection pool growing like this. I currently have a cron task that does a graceful restart of Apache after 300 connections. Can anyone shed some light on this or point me to some other resource for help? Thanks. -- Daryl Stultz _ 6 Degrees Software and Consulting, Inc. http://www.6degrees.com mailto:da...@6degrees.com
Re: Apache Tomcat\connection problem\Windows XP
Frank, > | I went to the Apache.org website and downloaded and installed the > | Windows executable under Core distributions, i.e., > | > | Core: > | a.. zip (pgp, md5) > | b.. tar.gz (pgp, md5) > | c.. Windows Executable (pgp, md5) Which of these did you install? Typically, you only choose one. > | The install went fine, but when I try to start Apache Tomcat, it just > | gives me the standard error message, "unable to connect." > | > | This happens even after I start the Apache service known as > | "Configure Tomcat" within the Apache Tomcat folder (or directory). Generally, Windows services are started using the service manager. Right-click on My Computer and choose "Manage". Then, go to "Services and Applications", then "Services". Try starting Apache Tomcat from there. > | I'm guessing I need to install one or two other important files or > | apps, > | as well as do some configuring, similar to setting JAVA_HOME, and > | executing (./ in Unix) the startup file (or .bat) in Windows. Just to make sure: you have installed Java, right? I think that you'll need to install it using the Windows "installer" instead of just downloading a ZIP file or something like that. Otherwise, the registry won't be set up correctly and Tomcat won't be able to find your JRE/JDK. (I'm not exactly sure how the Tomcat service determines which JDK to use, but I assume that it uses whatever Windows has configured in the registry). > | Any information is appreciated. Thanks. Your problem it likely to be your configured connectors, actually. When Tomcat starts up, you can startup any number of "connectors" that will handle requests. For example, you can start up the HTTP connector which will accept regular HTTP requests on a certain port. You can do the same thing with AJP13 if you want to connect to Tomcat through Apache httpd. Check $TOMCAT_HOME/conf/server.xml to see what connectors have been configured. Just search for " signature.asc Description: OpenPGP digital signature
Apache Tomcat\connection problem\Windows XP
Hello, | |This is a new post, and I am a newbie (at least to Apache Tomcat on | Windows). | | I went to the Apache.org website and downloaded and installed the | Windows executable under Core distributions, i.e., | | Core: | a.. zip (pgp, md5) | b.. tar.gz (pgp, md5) | c.. Windows Executable (pgp, md5) | The install went fine, but when I try to start Apache Tomcat, it just | gives me the standard error message, "unable to connect." | | This happens even after I start the Apache service known as | "Configure Tomcat" within the Apache Tomcat folder (or directory). | | I'm guessing I need to install one or two other important files or apps, | as well as do some configuring, similar to setting JAVA_HOME, and | executing (./ in Unix) the startup file (or .bat) in Windows. | | Any information is appreciated. Thanks. | | fjm
