Tomcat crashes with error java.lang.OutOfMemoryError: GC overhead limit exceeded

问题

After the tomcat ran several months, I got unexpectetly the error below. We restarted the tomcat and the error do not appear now but may be will come again in the future. I saw that another users had simmilar exceptions, related with the garbage collection, but not related exactly with the NIO connector.

Does somebody has an idea why this happens and what should be the correct fix to avoid it.

Jan 15, 2016 7:46:47 AM org.apache.tomcat.util.net.NioEndpoint$SocketProcessor run
SEVERE: 
java.lang.OutOfMemoryError: GC overhead limit exceeded
        at java.util.Collections.synchronizedSet(Collections.java:1691)
        at org.atmosphere.cpr.AtmosphereRequest$Builder.<init>(AtmosphereRequest.java:1146)
        at org.atmosphere.cpr.AtmosphereRequest.wrap(AtmosphereRequest.java:1891)
        at org.atmosphere.cpr.AtmosphereServlet.event(AtmosphereServlet.java:295)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilterEvent(ApplicationFilterChain.java:484)
        at org.apache.catalina.core.ApplicationFilterChain.doFilterEvent(ApplicationFilterChain.java:377)
        at org.apache.catalina.core.StandardWrapperValve.event(StandardWrapperValve.java:411)
        at org.apache.catalina.core.StandardContextValve.event(StandardContextValve.java:146)
        at org.apache.catalina.valves.ValveBase.event(ValveBase.java:224)
        at org.apache.catalina.core.StandardHostValve.event(StandardHostValve.java:256)
        at org.apache.catalina.valves.ValveBase.event(ValveBase.java:224)
        at org.apache.catalina.valves.ValveBase.event(ValveBase.java:224)
        at org.apache.catalina.core.StandardEngineValve.event(StandardEngineValve.java:138)
        at org.apache.catalina.connector.CoyoteAdapter.event(CoyoteAdapter.java:210)
        at org.apache.coyote.http11.Http11NioProcessor.event(Http11NioProcessor.java:124)
        at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1690)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:744)

回答1:

Either your server didn't have enough memory to manage some particularly memory-consuming task, or you have a memory leak.

For the first case, you may want to change memory settings of tomcat with -Xmx and -Xms VM arguments, see Java VM options .

This topic shows a full example for Tomcat : Increase Tomcat memory settings

For the second case, you should create a heap dump, with jmap for instance.

A heap dump file represents the current heap allocation of a java process.

jmap -dump:file=<file-name> <process-id>

Here, <file-name> is the file you want to create, and <process-id> is the id of the Tomcat process.

Some tools like Eclipse MAT , can open and analyze a heap dump file, tell you the number of objects by class, occupied memory by object types, memory leak suspects, and so on...

回答2:

OPTION 1 CATALINA.BAT

If you are running Tomcat from the following (Windows):

catalina.bat start

Then, you should create a file setenv.bat and add the following line:

set JAVA_OPTS="-Xms4096m -Xmx4096m"

OPTION 2 CATALINA.SH

If you are running Tomcat from the following (Linux):

catalina.sh start

Then, you will have to do a similar thing and create setenv.sh adding something like the following:

export JAVA_OPTS="-Xms4096m -Xmx4096m"

See also Increase Tomcat memory settings

OPTION 3 TOMCAT SERVICE

If you are running Tomcat from a Windows Service that was installed using the Tomcat installer, go to the Windows command prompt and run something like this (this is for Tomcat 8 and can be found in something like "C:\Program Files\Apache Software Foundation\Tomcat 8.0\bin"):