Tips to Counter JMeter Out of Memory Error

Often while running load test with too many users, JMeter may experience out of memory error. Reasons for this error could be many. And troubleshooting the error takes a significant amount of time. Therefore to help you in debugging JMeter out of memory error, here we have listed down some possible culprits and some solutions to counter them.

Let’s check out each of them in detail.

• Heap memory: JMeter may require more Heap memory than the allocated. It is set to 512 MB by default. You can increase that limit to allow more Heap memory to JMeter. For this, edit your jmeter.bat file in any editor and change values of “set HEAP=-Xms512m -Xmx512m” parameter.
• GUI mode: If you are not debugging your JMeter script, it is advisable to run it in Non-GUI mode. Click here to know more about it. Running JMeter in Non-GUI mode ensures less resource consumption.
• Listeners: Disable listeners such as Graph Result, View Result Tree which requires more system resources. Only use these listeners if you are debugging your JMeter script.
• JMeter version: Always use latest version of JMeter as they come with stability and performance improvements.
• Post-processors: Post processors in your JMeter script consumes resources. Use them wisely and efficiently. Disable/Remove them if they are not required.
• Script complexity: Make sure your JMeter script is not unnecessarily complex. JMeter will hog much more resources if your script happens to be complex. Consider taking necessary steps to simplify your script.
• Your system upgrade: If all else fails, consider upgrading your system CPU/RAM as it may be the cause of bottleneck.

Did you find the above tips to counter JMeter out of memory error useful? Do you know any more possible solution to tackle this problem? If you have any more suggestions, do share with us using comments below.