out of memory error:java heap space is coming in jmeter

Question

First I a ran jmeter with tomcat server on an 8Gb virtual machine in GUI and non-GUI mode but I got the error for 500 users

Caused by: java.net.SocketExecption: Connection reset by peer: Socket write error 

Now I have taken the tomcat server to a 16Gb dedicated system to run jmeter for 400 users in GUI mode I am getting this error:

Uncaught exception:java.lang.OutofmemoryError: Java heap space/ GC overhead limit exceeds even after changing the heap size in jmeter.sh file, jmeter.file and windows batch file

What could be causing this problem?

Answer 1

As per Java Garbage Collection handbook

The java.lang.OutOfMemoryError: GC overhead limit exceeded error is the JVM’s way of signalling that your application spends too much time doing garbage collection with too little result. By default the JVM is configured to throw this error if it spends more than 98% of the total time doing GC and when after the GC only less than 2% of the heap is recovered

Try out the following settings:

• Increase the JVM heap allocated to JMeter to be around 80% of your total available physical RAM
• Switch to CMS garbage collector by adding -XX:+UseConcMarkSweepGC argument to JVM
• Make sure you are following JMeter Best Practices and recommendations from 9 Easy Solutions for a JMeter Load Test “Out of Memory” Failure guide