The hudson.security.csrf.CrumbFilter generates so many log entries it causes parts of Jenkins to stall until the rate of log messages slows down.

2018-02-24 05:17:10.406+0000 [id=20011] WARNING hudson.security.csrf.CrumbFilter#doFilter: Found invalid crumb 418axxxx20cb74b577eaae393aa8ac0e. Will check remaining parameters for a valid one...
2018-02-24 05:17:10.406+0000 [id=20011] WARNING hudson.security.csrf.CrumbFilter#doFilter: No valid crumb was included in request for /$stapler/bound/419618ba-22aa-4afb-8528-b112a604cce9/getOnlineSlaves by joecool. Returning 403.

 
The amount of these logs was causing my Jenkins to stop working: The executors were not being released by jobs (even after they were done running) until the log entry could be written.

I checked through the logs and all the entries I have are for these URLs (there could be more, due to the logs rolling so quick):

• /$stapler/bound/419618ba-22aa-4afb-8528-b112a604cce9/getDisconnectedSlaves
• /$stapler/bound/419618ba-22aa-4afb-8528-b112a604cce9/getOfflineSlaves
• /$stapler/bound/419618ba-22aa-4afb-8528-b112a604cce9/getOnlineSlaves
• /$stapler/bound/419618ba-22aa-4afb-8528-b112a604cce9/getRunningJobs
• /$stapler/bound/419618ba-22aa-4afb-8528-b112a604cce9/getSlaves
• /$stapler/bound/419618ba-22aa-4afb-8528-b112a604cce9/getTasksInQueue

I would suggest that either these logs shouldn't be generated at all, or only as FINE or FINER entries.