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From Quinn Stevenson <qu...@pronoia-solutions.com>
Subject Re: Separate kahadb for queues and dead letter queues?
Date Fri, 29 Apr 2016 15:29:14 GMT
Wildcards aren’t quite that flexible - the docs say “don’t specify any string after ‘>’
on your wildcard express, it will be ignored” http://activemq.apache.org/wildcards.html
<http://activemq.apache.org/wildcards.html>

For what it’s worth - I got around this issue with DLQs by changing the naming pattern -
I put DLQ at the front, rather than the end.

> On Apr 29, 2016, at 9:25 AM, Christian Schneider <chris@die-schneider.net> wrote:
> 
> I just tested by sending messages into a queue test. Unfortunately the filter ">.DLQ"
seems to include "test". So it seems everything after ">" is ignored.
> Is there any way to express that I want all queues that end in DLQ?
> 
> Christian
> 
> On 29.04.2016 17:17, Christian Schneider wrote:
>> I took a stab at creating a config with a separate kahadb for the DLQs:
>> 
>>    <mKahaDB directory="${activemq.base}/data/kahadb">
>>        <filteredPersistenceAdapters>
>>            <filteredKahaDB queue=">.DLQ">
>>                <persistenceAdapter>
>>                    <kahaDB />
>>                </persistenceAdapter>
>>            </filteredKahaDB>
>>            <filteredKahaDB>
>>                <persistenceAdapter>
>>                    <kahaDB />
>>                </persistenceAdapter>
>>            </filteredKahaDB>
>>        </filteredPersistenceAdapters>
>>    </mKahaDB>
>> 
>> Does that make sense?
>> 
>> I am unsure about the ">" wildcard as I am not sure if it can be used at the start.
All examples I found till now only seem to use it at the end.
>> I would be happy about a confirmation that what I do is correct or a better solution.
>> 
>> Christian
>> 
>> On 29.04.2016 14:39, Christian Schneider wrote:
>>> We have the issue that our journals at a customer are very large. We analyzed
the messages in the system and found that most of the time
>>> the normal queues stay at a very low number of messages near to 0. The only queues
that hold messages for longer periods of time are the dead letter queues.
>>> 
>>> The journals are much bigger than the dead letter queue contents.
>>> 
>>> My assumption is that most of the journals only contain very few still needed
messages and the ones they contain are the messages that now are in the dead letter queues.
>>> Still the journals can not be cleaned up of course.
>>> 
>>> So what I would like to to is to use one kahadb for the regular queues and a
different one for the dead letter queues. Does that make sense?
>>> I will try to do this using "Multi(m) kahaDB persistence adapter": See http://activemq.apache.org/kahadb.html
>>> 
>>> I also wonder if it would make sense that ActiveMQ cleans up its journals regularly.
It could simply move all oldest messages to the newest jorunal to kind of pack if denser.
>>> Would that work?
>>> 
>>> Christian
>>> 
>> 
>> 
> 
> 
> -- 
> Christian Schneider
> http://www.liquid-reality.de
> 
> Open Source Architect
> http://www.talend.com
> 


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