Tomcat Won't Start on Linux

[hundel]

When starting an empty/basic standalone Tomcat 5.5 on Linux kernel 2.4.1, GLIBC 2.3, with Java 1.5.0 and LD_ASSUME_KERNEL=2.2.5 we receive the following exception. Removing LD_ASSUME_KERNEL resolves the problem, but the release notes specify it, and we've heard the server could lock up without it. Thoughts?

java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:271)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:409)
Caused by: java.lang.OutOfMemoryError: unable to create new native thread
at java.lang.Thread.start0(Native Method)
at java.lang.Thread.start(Thread.java:574)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.<init>(ThreadPool.java:643)
at org.apache.tomcat.util.threads.ThreadPool.openThreads(ThreadPool.java:515)
at org.apache.tomcat.util.threads.ThreadPool.start(ThreadPool.java:148)
at org.apache.tomcat.util.net.PoolTcpEndpoint.startEndpoint(PoolTcpEndpoint.java:315)
at org.apache.coyote.http11.Http11Protocol.start(Http11Protocol.java:176)
at org.apache.catalina.connector.Connector.start(Connector.java:992)
at org.apache.catalina.core.StandardService.start(StandardService.java:459)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:2010)
at org.apache.catalina.startup.Catalina.start(Catalina.java:537)
... 6 more

 

[sedj]

Have you tried invoking the JVM with a switch to give the JVM more memory (-Xms256m -Xmx256m - you'll need to hack the catalina.sh to do this) ?

Where have you *heard* that the JVM will lock if you don't specify this env var ?

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[hundel]

Thanks sedj -

We're specifying -Xmx much higher than 256m, but from my reading online, "unable to create new native thread" is not really related to heap size.

There's a good amount of detail online regarding how Linux upgraded their threading model, causing java's monitor to stop letting new threads into synchronized sections (we've experienced it) and this is the apparent reason for the Tomcat release note specifying LD_ASSUME_KERNEL=2.2.5 for glibc v2.2 - it reverts the Linux thread model to an older version that is more friendly to Java.

 

[sedj]

Its funny ... I've not yet tried 5.5, am on 5.0.25, but have seen a couple of posts here with people with similar problems, even on Windows ... I think I'll leave 5.5 for a while !

Like you, I'm sure its not a heap problem, but you never know ! Perhaps contact your vendor ?

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[hundel]

sedj - Sadly, this occured first on Tomcat 5.0. Upgrade to 5.5 was our first attempt to resolve the issue. Also, other Linux servers can successfully run this configuration. They seem to have a slightly different Linux patchset.

 

[sedj]

which linux you running ?


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[hundel]

Red Hat Enterprise Linux ES release 3 (Taroon Update 3)

Linux webforms05 2.4.21-20.ELsmp #1 SMP Wed Aug 18 20:46:40 EDT 2004 i686 i686 i386 GNU/Linux

 

[hundel]

LD_ASSUME_KERNEL=2.4.1 works like a charm, but Tomcat documentation prescribes that for Redhat Linux 9.

 

[sedj]

Weird ... I've used Tomcat on Red Hat 7, 8, 9, Fedora core 1 & 2, SuSe 9, Solaris 8, 9 and never had these problems. Oh well !

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[hundel]

Apparently, it is related to the latest kernel patchset. We're going to upgrade a working server to that patchset and confirm. If that's the case, we're going to have to do a lot of testing to confirm 2.4.1 is a stable threading model for Tomcat on our version of Linux. We have been through the horrible thread deadlocking that occurs when Tomcat is run in a high-use production setting on Linux and the thread model is not reverted as required in the release notes.

 

[sedj]

Interesting ... will keep a look out for that as we also use Linux as our web servers ...

Good luck anyway



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