Issue

• Jenkins UI is running incredibly slow
• Pipeline Stage View UI is not responding or running slowly
• Pipeline Builds are never finishing
• Loops are defined in the slow Pipeline.

Environment

• CloudBees CI (CloudBees Core) on modern cloud platforms - Managed Master
• CloudBees CI (CloudBees Core) on traditional platforms - Client Master
• CloudBees Jenkins Enterprise - Managed Master
• CloudBees Jenkins Platform - Client Master
• CloudBees Jenkins Distribution
• Jenkins LTS

Resolution

Try not to use use infinite while loops inside of Pipeline code.
A better alternative would be a Retry + Sleep blocks.

This will eliminate the possibility of an endless cycle of a build because it will stop trying after a certain number of attempts.
Additionally it ensures that a failure is recorded if the the looped step is unsuccessful.

References

• Pipeline as Code in Jenkins