Re: Tomcat dies suddenly

[Carl]

Mark,

Thanks for your quick reply.
Can I run the 32 bit JVM on the 64 bit linux (I think I can but just wanted 
to confirm)?

Thanks,

Carl
----- Original Message ----- 
From: "Mark Thomas" <ma...@apache.org>
To: "Tomcat Users List" <users@tomcat.apache.org>
Sent: Friday, January 29, 2010 3:18 PM
Subject: Re: Tomcat dies suddenly


On 29/01/2010 19:54, Carl wrote:
6-7 weeks ago, we built up some new servers and started having sudden 
failures... Tomcat just stops with no error message, no system error 
messages, nothing that I have been able to find so far.

To refresh everyone's memory, this is a new server, a Dell T110 with a 
Xeon 3440 processor and 4GB memory.  I have turned off both the turbo 
mode and hyperthreading.

The environment:

64 bit Slackware Linux

java version "1.6.0_17"
Java(TM) SE Runtime Environment (build 1.6.0_17-b04)
Java HotSpot(TM) 64-Bit Server VM (build 14.3-b01, mixed mode)

Tomcat: apache-tomcat-6.0.20

These are the current 
JAVA_OPTS="-Xms1024m -Xmx1024m -XX:PermSize=368m -XX:MaxPermSize=368m"

I have observed the memory usage and general performance with Java 
VisualVM and have seen nothing strange.  I thought I was seeing GC as 
memory usage was going up and down but in fact it was mostly people 
coming onto the system and leaving it.  After several hours, the memory 
settles to a baseline of about 375MB.  Forced GC never takes it below 
that value and the ups and downs from the people coming onto and leaving 
the system also returns it to pretty much that value.  The maximum memory 
used never was above 700MB for the entire day.

The server runs well, idling along at 2-5% load, except for a quick spike 
during GC, serving jsp's, etc. at a reasonable speed.  Without warning 
and with no tracks in any log (Tomcat or system) or to the console, 
Tomcat just shuts down.  I can usually simply restart it as the ports 
used by Tomcat are closed... today, I needed to run shutdown.sh before I 
could run startup.sh (startup.sh gave no errors but would not start 
Tomcat until I ran shutdown.sh and that process put nothing in the 
logs... this is the first time this has happened.)

Sometimes, the system will run for a week, sometimes for only several 
hours, sometimes only for a few minutes.  Today, it ran until about 
1:00PM and has been down four times since then.

The failure (Tomcat shutting down) is not always the same place in the 
code (I have some debugging messages going to catalina.out.)

Load does not seem to make a difference.

I have tried another sever (Dell T105, AMD processor, 6GB memory) and 
have observed the same results.   I have run memTest86 on the T110 for 
about 30 hours and it showed nothing.

I rebuilt the T110 with SUSE linux, Java 1.6.18 and Tomcat 6.0.24... it 
lasted 15 minutes.  I have used the same server.xml on all the installs:

<Server port="8005" shutdown="SHUTDOWN">
<!--APR library loader. Documentation at /docs/apr.html -->

<Listener className="org.apache.catalina.core.AprLifecycleListener" 
SSLEngine="on" />

<!--Initialize Jasper prior to webapps are loaded. Documentation at 
/docs/jasper-howto.html -->

<Listener className="org.apache.catalina.core.JasperListener" />

<!-- JMX Support for the Tomcat server. Documentation at 
/docs/non-existent.html -->

<Listener className="org.apache.catalina.mbeans.ServerLifecycleListener" 
/>

<Listener 
className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" 
/>

<!-- Global JNDI resources

Documentation at /docs/jndi-resources-howto.html

-->

<GlobalNamingResources>

<!-- Editable user database that can also be used by

UserDatabaseRealm to authenticate users

-->

<Resource name="UserDatabase" auth="Container"

type="org.apache.catalina.UserDatabase"

description="User database that can be updated and saved"

factory="org.apache.catalina.users.MemoryUserDatabaseFactory"

pathname="conf/tomcat-users.xml" />

</GlobalNamingResources>

<!-- A "Service" is a collection of one or more "Connectors" that share

a single "Container" Note: A "Service" is not itself a "Container",

so you may not define subcomponents such as "Valves" at this level.

Documentation at /docs/config/service.html

-->

<Service name="Catalina">


<!--The connectors can use a shared executor, you can define one or more 
named thread pools-->

<!--

<Executor name="tomcatThreadPool" namePrefix="catalina-exec-"

maxThreads="150" minSpareThreads="4"/>

-->



<!-- A "Connector" represents an endpoint by which requests are received

and responses are returned. Documentation at :

Java HTTP Connector: /docs/config/http.html (blocking & non-blocking)

Java AJP Connector: /docs/config/ajp.html

APR (HTTP/AJP) Connector: /docs/apr.html

Define a non-SSL HTTP/1.1 Connector on port 8080

-->

<Connector port="8080" protocol="HTTP/1.1"

maxHttpHeaderSize="8192"

maxThreads="600" minSpareThreads="25" maxSpareThreads="75"

enableLookups="false" redirectPort="8443" scheme="http" acceptCount="100"

connectionTimeout="20000" disableUploadTimeout="true" />

<!-- A "Connector" using the shared thread pool-->

<!--

<Connector executor="tomcatThreadPool"

port="8080" protocol="HTTP/1.1"

connectionTimeout="20000"

redirectPort="8443" />

-->

<!-- Define a SSL HTTP/1.1 Connector on port 8443

This connector uses the JSSE configuration, when using APR, the

connector should be using the OpenSSL style configuration

described in the APR documentation -->


<Connector port="8443" maxHttpHeaderSize="8192"

maxThreads="600" minSpareThreads="25" maxSpareThreads="75"

enableLookups="false" disableUploadTimeout="true"

acceptCount="100" scheme="https" secure="true"

clientAuth="false" sslProtocol="TLS" SSLEnabled="true"

keystoreFile="/usr/local/certs/tomcat_keystore.ks" 
keystorePass="jellybean"/>


<!-- Define a SSL HTTP/1.1 Connector on port 443 -->


<Connector port="443" maxHttpHeaderSize="8192"

maxThreads="600" minSpareThreads="25" maxSpareThreads="75"

enableLookups="false" disableUploadTimeout="true"

acceptCount="100" scheme="https" secure="true"

clientAuth="false" sslProtocol="TLS" SSLEnabled="true"

keystoreFile="/usr/local/certs/tomcat_keystore.ks" 
keystorePass="jellybean"/>


<!--

<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"

maxThreads="150" scheme="https" secure="true"

clientAuth="false" sslProtocol="TLS" />

-->

<!-- Define an AJP 1.3 Connector on port 8009 -->

<Connector port="8009"

enableLookups="false" redirectPort="443" protocol="AJP/1.3" />



<!-- An Engine represents the entry point (within Catalina) that 
processes

every request. The Engine implementation for Tomcat stand alone

analyzes the HTTP headers included with the request, and passes them

on to the appropriate Host (virtual host).

Documentation at /docs/config/engine.html -->

<!-- You should set jvmRoute to support load-balancing via AJP ie :

<Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm1">

-->

<Engine name="Catalina" defaultHost="localhost">

<!--For clustering, please take a look at documentation at:

/docs/cluster-howto.html (simple how to)

/docs/config/cluster.html (reference documentation) -->

<!--

<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>

-->

<!-- The request dumper valve dumps useful debugging information about

the request and response data received and sent by Tomcat.

Documentation at: /docs/config/valve.html -->

<!--

<Valve className="org.apache.catalina.valves.RequestDumperValve"/>

-->

<!-- This Realm uses the UserDatabase configured in the global JNDI

resources under the key "UserDatabase". Any edits

that are performed against this UserDatabase are immediately

available for use by the Realm. -->

<Realm className="org.apache.catalina.realm.UserDatabaseRealm"

resourceName="UserDatabase"/>

<!-- Define the default virtual host

Note: XML Schema validation will not work with Xerces 2.2.

-->

<Host name="localhost" appBase="webapps"

unpackWARs="true" autoDeploy="true" deployOnStartup="true"

xmlValidation="false" xmlNamespaceAware="false">

<!-- SingleSignOn valve, share authentication between web applications

Documentation at: /docs/config/valve.html -->

<!--

<Valve className="org.apache.catalina.authenticator.SingleSignOn" />

-->

<!-- Access log processes all example.

Documentation at: /docs/config/valve.html -->

<!--

<Valve className="org.apache.catalina.valves.AccessLogValve" 
directory="logs"

prefix="localhost_access_log." suffix=".txt" pattern="common" 
resolveHosts="false"/>

-->

</Host>

</Engine>

</Service>

</Server>

When Tomcat shuts down, the memory that it was using seems to still be 
held (as seen from top) but it is nowhere near the machine physical 
memory.

The application has been running on an older server (Dell 600SC, 32 bit 
Slackware, 2GB memory) for several years and, while the application will 
throw exceptions now and then, it never crashed.  This lead me to believe 
the problem had something to do with the 64 bit JVM but, with without 
seeing errors anywhere, I can't be certain and don't know what I can do 
about it except go back to 32 bit.

Given the circumstances, that seems like a reasonable next step.

Anyone have any ideas how I might track this problem down?

It sounds like it is going to be trial an error.

The closest I have seen to this was a web application that hung on
Tomcat start. It appeared to be one or more gc bugs in the 64-bit JVM. I
had one set options gc options that worked on Solaris and failed on
linux and another set that worked on linux but failed on Solaris. I
never did find a set that worked on both.

When Tomcat shuts down, I assume there is no java process left running.
i.e. the process dies rather than hangs.

Mark



---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org
For additional commands, e-mail: users-h...@tomcat.apache.org




---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org
For additional commands, e-mail: users-h...@tomcat.apache.org