[UIMA-5906] UIMA-AS: Fix NPE when sending thread is interrupted

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0AS
• Component/s: Async Scaleout
• Assignee: Jaroslaw Cwiklik
• Reporter: Jaroslaw Cwiklik
• Created: 13/Nov/18 20:11
• Updated: 16/Nov/18 16:54
• Resolved: 16/Nov/18 16:54

Description

A user reported the following scenario:

when sendAndReceiveCas() of an AS Engine is Thread.interrupt()-ed it can happen that the ActiveMQMessageSender does not have a cacheEntry of the CAS that's sending the request anymore [1] for that a warning is logged.
However directly after that the cacheEntry is deferenced leading to a NPE [2].
This exception will then be swallowed by BaseMessageSender [3] and the process will be retried [4].

This behavior is rather unfortunate.
It would be benefitial to add a null check at [2] that the cacheEntry is there before accessing ist. Also at [3] instead of swallowing all exceptions they should be logged at debug level.