Confluence crashes and throws 'OutOfMemory: unable to create new native thread' error
Platform notice: Server and Data Center only. This article only applies to Atlassian products on the server and data center platforms.
The confluence application occasionally crashes and throws an
OutOfMemoryError as below in the
Exception in thread "http-bio-8506-exec-106" java.lang.OutOfMemoryError: unable to create new native thread at java.lang.Thread.start0(Native Method) at java.lang.Thread.start(Thread.java:691) at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:943) at java.util.concurrent.ThreadPoolExecutor.processWorkerExit(ThreadPoolExecutor.java:992) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) at java.lang.Thread.run(Thread.java:722)
- In certain cases on Solaris, it appears that this can also cause the Java application to completely crash and generate a core dump.
To provide concurrency (the ability to do multiple things at once), Java will spawn operating system threads and use them to perform tasks. Hard limits can be set at the system level on the number of threads that can be created, so if the application is requesting more threads than the OS is willing to provide, the above error is thrown. This occurs in the following way:
- A new Java thread is requested by confluence applications. This can be by anything.
- JVM native code proxies the request to create a new native thread to the OS.
- The operating system attempts to create a new native thread. As it's a thread, it requires memory to be allocated to it.
- The operating system refuses the native memory allocation.
java.lang.OutOfMemoryError: unable to create new native threaderror is thrown.
This can also happen if the operating system has no native memory left to allocate threads (say the 32-bit Java process space has been reached, or the OS virtual memory is fully depleted), or the maximum number of open files has been reached.
$CONFLUENCE_INSTALL/bin/setenv.shfile and add the below to the top of the file:
ulimit -u 4096 ulimit -n 4096
These values may be different depending upon the operating system used, consult with your System Administrator / hosting provider about the most appropriate limits to set.
It's recommended to set this value permanently as in the resolution.
Setting the maximum running user processes and number of opened files permanently is recommended, and the implementation of this is operating system specific. These can be set in Debian / Ubuntu in limits.conf by adding the below:
confluence soft nofile 4096 confluence hard nofile 8192 confluence soft nproc 4096 confluence hard nproc 8192
confluence with the user that runs Confluence.