- After upgrading CloudBees Core to release 220.127.116.11, Kubernetes planned agents are stuck in “Pending” and builds are hanging forever, waiting for the planned agents to come online with “Waiting for next available executor”.
- In such cases, the agent pod are not even scheduled
- CloudBees Core 18.104.22.168
- CloudBees Core on Modern Cloud Platforms - Managed Master 22.214.171.124
- CloudBees Core on Modern Cloud Platforms - Operations Center 126.96.36.199
- CloudBees Core on Traditional Platforms - Client Master 188.8.131.52
- CloudBees Core on Traditional Platforms - Operations Center 184.108.40.206
- CloudBees Jenkins Platform - Client Master 220.127.116.11
- CloudBees Jenkins Platform - Operations Center 18.104.22.168
- CloudBees Jenkins Distribution 22.214.171.124
- Jenkins LTS
- Kubernetes Plugin from version 1.19.1 to 1.21.2 (excluded)
This is a bug in the kubernetes plugin introduced by JENKINS-56307 in version 1.19.1 of the kubernetes plugin.
This version introduces a new Node Provisioner strategy
NoDelayProvisionerStrategy that is enabled by default. The strategy provisions a node as soon as the Node Provisioner detects a need for more agents. As opposed to the default strategy that makes his decision based on load estimates.
There is a bug in the implementation that causes agents to never be provisioned and builds to hang.
This issue has been fixed in version 1.21.2 of the kubernetes plugin.
The solution is to upgrade the Kubernetes plugin to version 1.21.2 that contains the fix
Note At the moment of writing this article, this version is not yet available under the CloudBees Assurance Program
The workaround is to disable the
NoDelayProvisionerStrategy. This can be done by adding the system property
-Dio.jenkins.plugins.kubernetes.disableNoDelayProvisioning=true to the Master’s startup. This requires to restart the Master in order to take effect. See How to add Java arguments to Jenkins to under stand how to do this.