You are viewing a plain text version of this content. The canonical link for it is here.
Posted to oak-issues@jackrabbit.apache.org by "Andrei Dulceanu (JIRA)" <ji...@apache.org> on 2018/02/05 11:23:00 UTC
[jira] [Resolved] (OAK-7162) Race condition on revisions head
between compaction and scheduler could result in skipped commit
[ https://issues.apache.org/jira/browse/OAK-7162?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Andrei Dulceanu resolved OAK-7162.
----------------------------------
Resolution: Fixed
> Race condition on revisions head between compaction and scheduler could result in skipped commit
> ------------------------------------------------------------------------------------------------
>
> Key: OAK-7162
> URL: https://issues.apache.org/jira/browse/OAK-7162
> Project: Jackrabbit Oak
> Issue Type: Bug
> Components: segment-tar
> Affects Versions: 1.8.0
> Reporter: Andrei Dulceanu
> Assignee: Andrei Dulceanu
> Priority: Blocker
> Labels: scalability
> Fix For: 1.9.0, 1.10, 1.8.2
>
> Attachments: OAK-7162-02.patch, OAK-7162-03.patch, OAK-7162-test.patch, OAK-7162.patch
>
>
> There is a race condition on {{TarRevisions#head}} between a running compaction trying to set the new head [0] and the scheduler doing the same after executing a specific commit [1]. If the compaction thread is first, then the head assignment in the scheduler will fail and not be re-attempted.
> IMO, the simple if statement should be changed to a while loop in which the head is refreshed and the commit is re-applied against the new head, before attempting again to set a new head in {{TarRevisions}}. This is somehow similar to what we previously had [2], but without the unneeded optimistic/pessimistic strategies involving tokens.
> [0] https://github.com/apache/jackrabbit-oak/blob/trunk/oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/file/FileStore.java#L764
> [1] https://github.com/apache/jackrabbit-oak/blob/trunk/oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/scheduler/LockBasedScheduler.java#L253
> [2] https://github.com/apache/jackrabbit-oak/blob/1.6/oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/SegmentNodeStore.java#L686
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)