activemq-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Tim Bain (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (AMQ-5542) KahaDB data files containing acknowledgements are deleted during cleanup
Date Tue, 27 Jan 2015 21:35:35 GMT

    [ https://issues.apache.org/jira/browse/AMQ-5542?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14294232#comment-14294232
] 

Tim Bain commented on AMQ-5542:
-------------------------------

Doesn't the logic described here imply that we're almost never going to be able to delete
data files that follow the first unconsumed message?  Won't it usually be true that there's
at least one ack in file N+1 of a message in file N, for all values of N, so file N+1 will
always need to stick around for as long as N does?

> KahaDB data files containing acknowledgements are deleted during cleanup
> ------------------------------------------------------------------------
>
>                 Key: AMQ-5542
>                 URL: https://issues.apache.org/jira/browse/AMQ-5542
>             Project: ActiveMQ
>          Issue Type: Bug
>          Components: Message Store
>    Affects Versions: 5.10.0, 5.10.1
>            Reporter: Sergiy Barlabanov
>
> AMQ-2832 was not fixed cleanly.
> The commit dd68c61e65f24b7dc498b36e34960a4bc46ded4b by Gary from 8.10.2010 introduced
a problem by deleting too many files.
> Scenarios we are facing currently in production:
> Data file #1 contains unconsumed messages sitting in a DLQ. So this file is not a cleanup
candidate.
> The next file #2 contains acks of some messages from file #1. This file is not a cleanup
candidate (because of ackMessageFileMap logic).
> The next file #3 contains acks of some messages from file #2. And this file is deleted
during the cleanup procedure. So on Broker restart all messages from #2, whose acks were from
the deleted file #3, are replayed!
> The reason is gcCandidates variable, which is a copy of gcCandidateSet (see MessageDatabase#checkpointUpdate
at the end of the method - org/apache/activemq/store/kahadb/MessageDatabase.java:1659 on 5.10.0
tag). So when a candidate is deleted from gcCandidateSet (org/apache/activemq/store/kahadb/MessageDatabase.java:1668
on 5.10.0 tag), gcCandidates still contains that candidate and the comparison on org/apache/activemq/store/kahadb/MessageDatabase.java:1666
works wrong!
> I will try to adjust AMQ2832Test.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message