Re: HA ActiveMQ brokers running against a SQL Server 2008 database > large transaction logs

[Gary Tully <ga...@gmail.com>]

There are a few options.
 - use a separate database for the lock table, it is possible to
configure a separate datasource for the locker via config
- if you manually manage broker restart and can ensure exclusive
access to the activemq tables, you could disable locking via
configuration.
- you can implement a variation of the locker that uses over lapping
transactions or some update mechanism using timestamps and configure
it as the database locker
- you can implement a variation of the locker that uses some other
shared resource as a semaphore

some relevant issues that may give some more inspiration
 https://issues.apache.org/activemq/browse/AMQ-1244
 https://issues.apache.org/activemq/browse/AMQ-2520

On 10 August 2010 17:46, magellings <ma...@qg.com> wrote:
>
> Greetings,
>
> DBA with here with some questions for the ActiveMQ development and user
> community, hopefully you can provide some insight or relate experiences...
>
> We have HA ActiveMQ brokers running against a SQL Server 2008 database that
> is mirroring to secondary site.  During a recent failover we found that the
> oldest of the ActiveMQ databases took almost 35 minutes to open. The
> transaction log had grown to 13 GB despite regular backups.
>
> Our environment has dozens of servers and hundreds of databases, ActiveMQ is
> relatively new I our environment but has been running for months before a
> failover. (We are 24x7x365 shop and production requires HA, DR and fast
> recovery on system failures)
>
> We determined this was due to ActiveMQ broker keeping a open transaction and
> issuing a UPDATE statement every 30 seconds. It became clear that ActiveMQ
> brokers must commit those transactions or rollback sometime… to maintain log
> file size and allow speedy database failover to mirror. ActiveMQ is quickly
> becoming a HUB for communication between applications  and production
> processes.
>
> We are not using a witness in our standard mirroring setup so we do a manual
> failover utilizing DNS alias for maintaining client connectivity.
>
> We can set the broker lock UPDATE frequency lower or to once…but the
> transaction remains open and the transaction log would continue to grow.
>
> The other thought was to regularly cycle between the two brokers. This would
> close one broker server and transactions would commit or rollback and then
> the log file could be backed up and truncated. (My favorite idea…)
>
> What is the communities take on SQL Server Mirroring and has anyone utilized
> ActiveMQ HA persistent  broker configuration with SQL Server Mirroring?
>
> Thanks!
>
> --
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> Sent from the ActiveMQ - User mailing list archive at Nabble.com.
>
>



-- 
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