Problem Definition

Bamboo PlanExec thread pool is defaulted to 4. It has a max size of 8 but it never scales since it has a very large queue size and is linked to a dedupe queue. The thread pool is responsible for executing change detection operations and other parts of the build execution lifecycle.

4 threads has proven to be insufficient for large instances with a lot of change detection and non-optimal network conditions.

Suggested Solution

Slight increase to the initial size. E.g. 5, 6 or 8.

Utopian solution:
Scalable thread pool sizes based on load factors and queue drain rate.

Workaround

Higher than 8 is not recommended, please monitor Disk IO and CPU increases on the Bamboo Server after increasing this.

1. Linux: Edit your <bamboo-install>/bin/setenv.sh
   • Windows, please see the following on how to define additional arguments depending on the install: https://confluence.atlassian.com/bamboo/configuring-your-system-properties-289277345.html
2. Add the following -Dbamboo.plan.exe.threads=8 to your JVM_SUPPORT_RECOMMENDED_ARGS. E.g.

   #
   #  Occasionally Atlassian Support may recommend that you set some specific JVM arguments.  You can use this variable below to do that.
   #
   : ${JVM_SUPPORT_RECOMMENDED_ARGS:="-Dbamboo.plan.exe.threads=8"}
   

3. Restart Bamboo