XVNC plugin is not freeing allocated Displays after failed builds

Article ID:115002507248
1 minute readKnowledge base

Issue

After a failed build the XVNC plugin does not free up the allocated Display numbers and now I am out of allocated numbers

Environment

  • CloudBees Jenkins Enterprise

  • XVNC plugin

Resolution

The issue is that if a build fails, the XVNC does not clean up allocated display port numbers and the agent still thinks that port is being used. The issue is documented in JENKINS-40496 and will have a workaround in JENKINS-40430. The best solution we have right now is to use one of these scripts to free up allocated display port numbers:

  1. Port range:

     agentName = "XXX"
 displayNumbers=(25..28)
 DESCRIPTOR = Jenkins.getActiveInstance().getDescriptorByType(hudson.plugins.xvnc.Xvnc$DescriptorImpl.class)
 allocator = DESCRIPTOR.allocators.get(agentName);
 displayNumbers.forEach{displayNumber->
   println "Before: ${allocator.allocatedNumbers}"
   allocator.free(displayNumber)
   println "After: ${allocator.allocatedNumbers}"
 }

  2. Comma separated list:

     agentName = "XXX"
 displayNumbers=[25,26,27,28]
 DESCRIPTOR = Jenkins.getActiveInstance().getDescriptorByType(hudson.plugins.xvnc.Xvnc$DescriptorImpl.class)
 allocator = DESCRIPTOR.allocators.get(agentName);
 displayNumbers.forEach{displayNumber->
   println "Before: ${allocator.allocatedNumbers}"
   allocator.free(displayNumber)
   println "After: ${allocator.allocatedNumbers}"
 }

Put either one of those into your script console to have it free up the display numbers inside of the Brackets [].

This article is part of our Knowledge Base and is provided for guidance-based purposes only. The solutions or workarounds described here are not officially supported by CloudBees and may not be applicable in all environments. Use at your own discretion, and test changes in a safe environment before applying them to production systems.