Mailing-List: contact dev-help@activemq.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@activemq.apache.org
Message-ID: <28988083.212081296037364416.JavaMail.jira@thor>
Date: Wed, 26 Jan 2011 05:22:44 -0500 (EST)
From: "Gary Tully (JIRA)" <jira@apache.org>
To: dev@activemq.apache.org
Subject: [jira] Assigned: (AMQ-3161) Race condition in ActiveMQ Journal
 Checkpoint worker thread cleanup leads to multiple running instances
In-Reply-To: <6146144.202761295996144742.JavaMail.jira@thor>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


     [ 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.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.