How do I give Jenkins more heap space when it's running as a daemon on Ubuntu?

Question

My Jenkins jobs are running out of memory, giving java.lang.OutOfMemoryError messages in the build log. But I used the Ubuntu Package Manager, aptitude, or apt-get to install Jenkins, and I don't know where to look to change the amount of heap space allocated to Jenkins.

Solution 1

There are two types of OutOfMemoryError messages that you might encounter while a Jenkins job runs:

• java.lang.OutOfMemoryError: Heap space – this means that you need to increase the amount of heap space allocated to Jenkins when the daemon starts.
• java.lang.OutOfMemoryError: PermGen space – this means you need to increase the amount of generation space allocated to store Java object metadata. Increasing the value of the -Xmx parameter will have no affect on this error.

On Ubuntu 12.04 LTS, uncomment the JAVA_ARGS setting on line ten of /etc/default/jenkins:

• To add more Java heap space, increase the value of the -Xmx Java parameter. That sets the maximum size of the memory allocation pool (the garbage collected heap).
• To add more PermGen space, add the parameter XX:MaxPermSize=512m (replace 512 with something else if you want more. The permanent generation heap holds meta information about user classes.

For example, this extract is from the default /etc/default/jenkins after a fresh install of Jenkins:

# arguments to pass to java
#JAVA_ARGS="-Xmx256m"

This is how it would look if you set the heap space to be 1 GB:

# arguments to pass to java
JAVA_ARGS="-Xmx1048m"

Be careful not to set the heap size too large, as whatever you allocate reduces the amount of memory available to the operating system and other programs, which could cause excessive paging (memory swapped back and forth between RAM and the swap disc, which will slow your system down).

If you also set MaxPermSpace, you need to add a space between the parameters):

# arguments to pass to java
JAVA_ARGS="-Xmx1048m -XX:MaxPermSize=512m"

After making a change, restart Jenkins gracefully from the Jenkins web interface, or force an immediate restart from the command-line with sudo /etc/init.d/jenkins restart.

I found the following site useful for understanding Java maximum and permanent generation heap sizes: http://www.freshblurbs.com/blog/2005/05/19/explaining-java-lang-outofmemoryerror-permgen-space.html.

Solution 2

For CentOS, the directory the Jenkins.xml is located in by default is /etc/sysconfig/ for jenkins-1.579-1.1

JENKINS_JAVA_OPTIONS="-Djava.awt.headless=true -Xmx -XX:MaxPermSize="

Solution 3

If you are using Ubuntu Server, first install Monitoring plugin to see how much memory Jenkins is using. For example, this is what I saw after installing it:

Then, with the command free -m, I figured out what was the server's memory size. In my case, 16Gb. With that info, I opened /etc/default/jenkins and changed:

JAVA_ARGS="-Djava.awt.headless=true"

to

JAVA_ARGS="-Xmx8384m -Djava.awt.headless=true"

Where 8384 is 8Gb. Then I restarted Jenkins with the command sudo service jenkins restart and then, after triggering the job that was getting memory issues, things looked much better and the job could complete on this and subsequent runs:

Solution 4

Another method to set the heap size for particular jobs is to use environment variables for each job. This ensures that the memory is available when the job that requires a higher memory is not in use.

GRADLE_OPTS="-Dorg.gradle.jvmargs=-Xms1024M -Xmx8192M -XX:PermSize=512M -XX:MaxPermSize=2048 -XX:+CMSClassUnloadingEnabled -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8"

JAVA_OPTS="-XX:MaxPermSize=2048M"

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Comments

[Alper Akture]

I think you forgot the seconds dash, so it should be: JAVA_ARGS="-Xmx1048m -XX:MaxPermSize=512m"

[Steve HHH]

Thank-you! I've added the missing dash.

[CasualT]

I found that on my Ubuntu install that I had to go into /etc/init/jenkins.conf and add to the line JAVA_OPTS="". (editing the /etc/default location had no effect, and I confirmed this with jmap).

[FilBot3]

Is there way to do this in CentOS? I'm not finding a /etc/default/jenkins directory. And all fo the files that say Jenkins, or are located in jenkins directories don't say anything about Xmx, or memory.

[bmaher]

Cheers, I was nearly going mad trying to find this

[user1164061]

@Pred did you find a solution to your problem? I have the same issue with my jenkins slave and I dont know where I should these arguments to pass to java.Thanks!

[user3640967]

Argh! This has finally stopped my Jenkins installation from crashing after 3 days of hunting for the problem (thankyou!) But why on Earth is the Java default still just 256MB in 2016???

[user1053510]

On my openSUSE Leap 42.1 (x86_64) the Jenkins config for version 2.70 is located in /etc/sysconfig/jenkins

[carl verbiest]

also for RedHat RHEL 7.4, jenkins 2.98

[Assi.NET]

You can also say -Xmx8g which is the same as -Xmx8384m, but more easy.

[Assi.NET]

You can also say -Xmx8g which is the same as -Xmx8384m, but more easy.

[SaundersB]

Wouldn't 1GB be 1024MB?

[FooBar]

I don't see this setting anywhere, maybe you should describe more in detail where you found it.

[Gank]

[root@Berder-S-01 ~]# service jenkins restart Restarting jenkins (via systemctl): Job for jenkins.service failed because the control process exited with error code. See "systemctl status jenkins.service" and "journalctl -xe" for details. [FAILED]

[VanagaS]

@FooBar Those options come from environment injector plugin