[jira] [Updated] (AMQ-6545) Deadlock can occur during journal file rotation

["Christopher L. Shannon (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/AMQ-6545?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Christopher L. Shannon updated AMQ-6545:
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    Summary: Deadlock can occur during journal file rotation  (was: Deadlock can occur during Ack compaction)

> Deadlock can occur during journal file rotation
> -----------------------------------------------
>
>                 Key: AMQ-6545
>                 URL: https://issues.apache.org/jira/browse/AMQ-6545
>             Project: ActiveMQ
>          Issue Type: Bug
>          Components: Broker, KahaDB
>    Affects Versions: 5.14.2
>            Reporter: Christopher L. Shannon
>            Assignee: Christopher L. Shannon
>
> There is an issue in the KahaDB Journal that can cause a deadlock.  I saw the issue occur today when an Ack compaction was running while another thread retrieved the current data file and a rotation was required.
> https://issues.apache.org/jira/browse/AMQ-5603 introduced async preallocation and part of that commit introduced two locks instead of 1...dataFileIdLock and currentDataFile.
> The issue is that most of the time dataFileIdLock is acquired first and then currentDataFile.  However, when calling the getCurrentDataFile() method if a rotation is needed then the currentDataFile lock is acquired before dataFileIdLock leading to a potential deadlock situation.
> The fix is to make sure that the two locks are always acquired in the same order.



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