[JENKINS-39088] Improve OutOfMemory diagnostics in Jenkins Support Core

Currently Jenkins can recover from OutOfMemory errors in particular cases, but there are known issues like channel hanging.

They issue may stay unnoticed till it disappears from logs. In such case Jenkins admins may have no clue if it was a cause of connection hanging.

Proposals:

• Record last OOM events in support bundles (if they happen after the restart)


• Add an administrative monitor with a warning (Jenkins restart is recommended in general)

It may likely require patches in the Jenkins core

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Originally reported by oleg_nenashev, imported from: Improve OutOfMemory diagnostics in Jenkins Support Core

• assignee: schristou
  
• status: Open
  
• priority: Minor
  
• component(s): support-core-plugin
  
• resolution: Unresolved
  
• votes: 0
  
• watchers: 1
  
• imported: 20251212-090250
  

Raw content of original issue

Currently Jenkins can recover from OutOfMemory errors in particular cases, but there are known issues like channel hanging.


They issue may stay unnoticed till it disappears from logs. In such case Jenkins admins may have no clue if it was a cause of connection hanging.


Proposals:



	
Record last OOM events in support bundles (if they happen after the restart)

	
Add an administrative monitor with a warning (Jenkins restart is recommended in general)



It may likely require patches in the Jenkins core

Begin by inspecting the support-core plugin and the Jenkins core areas related to OutOfMemory handling, support bundles, and administrative monitors. Determine how OOM events after restart can be retained and how a restart warning should be surfaced; done means both proposed diagnostics are implemented and covered by appropriate tests.

Written by the indexing model from the issue text.