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Posted to dev@activemq.apache.org by "Craig Condit (JIRA)" <ji...@apache.org> on 2011/01/25 23:55:44 UTC
[jira] Created: (AMQ-3161) Race condition in ActiveMQ Journal
Checkpoint worker thread cleanup leads to multiple running instances
Race condition in ActiveMQ Journal Checkpoint worker thread cleanup leads to multiple running instances
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Key: AMQ-3161
URL: https://issues.apache.org/jira/browse/AMQ-3161
Project: ActiveMQ
Issue Type: Bug
Components: Message Store
Affects Versions: 5.4.2
Environment: CentOS 5.2
Reporter: Craig Condit
Priority: Critical
If the ActiveMQ Journal Checkpoint worker thread dies for any reason, any updates to KahaDB trigger the thread to be restarted. Unfortunately, there is a race condition between the Thread.isAlive() check and the restart of the thread, potentially leading to multiple instances of the thread being spawned. We have observed in a busy environment as many as 8-10 instances of this thread, all waking up every 5 seconds to perform database checkpoints, bringing throughput on the broker to a halt.
The attached patch adds a lock around access to creation/destruction of this thread and prevents a second instance from being launched inadvertently.
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[jira] Updated: (AMQ-3161) Race condition in ActiveMQ Journal
Checkpoint worker thread cleanup leads to multiple running instances
Posted by "Craig Condit (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/AMQ-3161?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Craig Condit updated AMQ-3161:
------------------------------
Attachment: checkpoint-thread.patch
This patch to MessageDatabase.java prevents accidental launching of multiple Journal checkpoint worker threads.
> Race condition in ActiveMQ Journal Checkpoint worker thread cleanup leads to multiple running instances
> -------------------------------------------------------------------------------------------------------
>
> Key: AMQ-3161
> URL: https://issues.apache.org/jira/browse/AMQ-3161
> Project: ActiveMQ
> Issue Type: Bug
> Components: Message Store
> Affects Versions: 5.4.2
> Environment: CentOS 5.2
> Reporter: Craig Condit
> Priority: Critical
> Attachments: checkpoint-thread.patch
>
>
> If the ActiveMQ Journal Checkpoint worker thread dies for any reason, any updates to KahaDB trigger the thread to be restarted. Unfortunately, there is a race condition between the Thread.isAlive() check and the restart of the thread, potentially leading to multiple instances of the thread being spawned. We have observed in a busy environment as many as 8-10 instances of this thread, all waking up every 5 seconds to perform database checkpoints, bringing throughput on the broker to a halt.
> The attached patch adds a lock around access to creation/destruction of this thread and prevents a second instance from being launched inadvertently.
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[jira] Resolved: (AMQ-3161) Race condition in ActiveMQ Journal
Checkpoint worker thread cleanup leads to multiple running instances
Posted by "Gary Tully (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/AMQ-3161?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Gary Tully resolved AMQ-3161.
-----------------------------
Resolution: Fixed
Fix Version/s: 5.5.0
patch applied with thanks in r1063710
URL: http://svn.apache.org/viewvc?rev=1063710&view=rev
one minor mod, left unsynced check in store, such that locking overhead occurs only if thread needs a restart.
> Race condition in ActiveMQ Journal Checkpoint worker thread cleanup leads to multiple running instances
> -------------------------------------------------------------------------------------------------------
>
> Key: AMQ-3161
> URL: https://issues.apache.org/jira/browse/AMQ-3161
> Project: ActiveMQ
> Issue Type: Bug
> Components: Message Store
> Affects Versions: 5.4.2
> Environment: CentOS 5.2
> Reporter: Craig Condit
> Assignee: Gary Tully
> Priority: Critical
> Fix For: 5.5.0
>
> Attachments: checkpoint-thread.patch
>
>
> If the ActiveMQ Journal Checkpoint worker thread dies for any reason, any updates to KahaDB trigger the thread to be restarted. Unfortunately, there is a race condition between the Thread.isAlive() check and the restart of the thread, potentially leading to multiple instances of the thread being spawned. We have observed in a busy environment as many as 8-10 instances of this thread, all waking up every 5 seconds to perform database checkpoints, bringing throughput on the broker to a halt.
> The attached patch adds a lock around access to creation/destruction of this thread and prevents a second instance from being launched inadvertently.
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[jira] Assigned: (AMQ-3161) Race condition in ActiveMQ Journal
Checkpoint worker thread cleanup leads to multiple running instances
Posted by "Gary Tully (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/AMQ-3161?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Gary Tully reassigned AMQ-3161:
-------------------------------
Assignee: Gary Tully
> Race condition in ActiveMQ Journal Checkpoint worker thread cleanup leads to multiple running instances
> -------------------------------------------------------------------------------------------------------
>
> Key: AMQ-3161
> URL: https://issues.apache.org/jira/browse/AMQ-3161
> Project: ActiveMQ
> Issue Type: Bug
> Components: Message Store
> Affects Versions: 5.4.2
> Environment: CentOS 5.2
> Reporter: Craig Condit
> Assignee: Gary Tully
> Priority: Critical
> Attachments: checkpoint-thread.patch
>
>
> If the ActiveMQ Journal Checkpoint worker thread dies for any reason, any updates to KahaDB trigger the thread to be restarted. Unfortunately, there is a race condition between the Thread.isAlive() check and the restart of the thread, potentially leading to multiple instances of the thread being spawned. We have observed in a busy environment as many as 8-10 instances of this thread, all waking up every 5 seconds to perform database checkpoints, bringing throughput on the broker to a halt.
> The attached patch adds a lock around access to creation/destruction of this thread and prevents a second instance from being launched inadvertently.
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