[jira] [Created] (ARTEMIS-3444) Paging cache entries are not evicted although eligible for GC

["Francesco Nigro (Jira)" <ji...@apache.org>]

Francesco Nigro created ARTEMIS-3444:
----------------------------------------

             Summary: Paging cache entries are not evicted although eligible for GC
                 Key: ARTEMIS-3444
                 URL: https://issues.apache.org/jira/browse/ARTEMIS-3444
             Project: ActiveMQ Artemis
          Issue Type: Improvement
            Reporter: Francesco Nigro
            Assignee: Francesco Nigro


Artemis Paging cache is using SoftValueLongObjectHashMap to collect page cache entries.

Soft references become eligible to be collected by JVM according to -XX:SoftRefLRUPolicyMSPerMB configuration and it affects when broker can remove such entries from the mentioned SoftValueLongObjectHashMap too.

The mechanism that allow broker to remove any pending memory is by processing the ref queue filled by the JVM, but it's going to happen only if there's any interaction with the page cache (size/put/remove/get/iteration), and that means that if there are no interactions, the broker won't remove such entries and the related reference queue will grow larger and larger, leading to huge GC reference processing pauses.

The paging cache should be able to remove such entries as soon as the JVM enqueue them on the map ref queue, instead.





--
This message was sent by Atlassian Jira
(v8.3.4#803005)