[JCR-2746] Sleep in possibly endless loop in ObservationDispatcher

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0, 2.1, 2.1.1
• Fix Version/s: 2.2
• Component/s: jackrabbit-core, observation
• Assignee: Thomas Mueller
• Reporter: Jukka Zitting
• Created: 14/Sep/10 09:30
• Updated: 29/Jun/16 13:28
• Resolved: 21/Sep/10 13:34

Description

The rate-limitation code we added in JCR-2402 to prevent the observation queue from growing too large was a good idea, but the current implementation is a bit troublesome since it blocks the thread while it still holds the journal lock, the SISM reader lock, and the SessionState lock. This can cause a deadlock under heavy workloads if any of the observation listeners attempts to reuse the session (not recommended/supported, but can still happen) or write to the repository (quite likely).

To solve this problem we should move the rate-limiter code to outside the scope of any internal locks.

Issue Links

• is related to: JCR-2402 Observation: avoid running out of memory