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https://issues.apache.org/jira/browse/AMQ-2922?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Gary Tully resolved AMQ-2922.
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Resolution: Fixed
rev: http://svn.apache.org/viewvc?rev=1170201&view=rev
Added a new multi kahaDB persistence adapter that supports distributing
destinations across n kahaDB adapters.
It is configured with a list of kahaDBs that are filtered using a destination
wildcard (like a policy entry). A filteredKahaDB entry without a destination
will match everything. When transactions include destinations that cross
persistence adapters, two phase completion is used so there is performance
penalty. It is best to keep transactions to a single persistence adapter.
Each kahaDB instance can be configured at will.
{code}
<persistenceAdapter>
<mKahaDB directory="${activemq.base}/data/kahadb">
<filteredPersistenceAdapters>
<!-- just all queues -->
<filteredKahaDB queue=">">
<persistenceAdapter>
<kahaDB />
</persistenceAdapter>
</filteredKahaDB>
<!-- everything -->
<filteredKahaDB>
<persistenceAdapter>
<kahaDB />
</persistenceAdapter>
</filteredKahaDB>
</filteredPersistenceAdapters>
</mKahaDB>
</persistenceAdapter>{code}
> Add ability for KahaDB log files to be created on a per-destination basis.
> --------------------------------------------------------------------------
>
> Key: AMQ-2922
> URL: https://issues.apache.org/jira/browse/AMQ-2922
> Project: ActiveMQ
> Issue Type: New Feature
> Components: Message Store
> Affects Versions: 5.4.0
> Environment: All
> Reporter: Peter Blackburn
> Assignee: Gary Tully
> Fix For: 5.6.0
>
> Attachments: activemq.xml, multistore.diff
>
>
> KahaDB persistence uses rolling log files to store unconsumed messages. These
> are named db-1.log, db-2.log ... db3.log. At present these files contain
> messages for all destinations managed by the broker.
> A configurable option could be added that would allow these files to be
> created on a per-destination basis. For example, if the broker contained two
> queue destinations, queue_1 and queue_2, the log files would become:
> queue_1-1.log, queue_1-2.log....etc
> queue_2-1.log, queue_2-2.log....etc
> Each set of log files would only contain messages for the relevant
> destination.
> This would help in the following situation:
> queue_1: receives one message every 15 seconds or so. These messages remain
> unconsumed for several hours.
> queue_2: receives thousands of messages per second. These messages are
> consumed as they arrive.
> At present, the scenario above leads to each log files containing a few
> messages that have yet to be consumed and thousands of messages that have
> been consumed, but the log file cannot be deleted until all messages logged
> in it have been consumed (which may be hours later).
> Logging on a per-destination basis would allow the log files for queue_2 in
> the above example to be deleted, meaning the unconsumed messages on queue_1
> take up far less disk space. This would also reduce the number of file
> handles required.
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