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From Matt Pavlovich <>
Subject Re: Does a persistent message stay (keep) on the broker forever ?
Date Tue, 24 Jan 2012 21:39:33 GMT

ActiveMQ does not permanently store messages on its one.  KahaDB will 
create a full-sized db-1.log (default is 32Mb) at start-up.  It stores 
messages in there, and as messages are created and consumed, it will 
create new db-*.log files as needed, and delete db-*.log files as 
messages are consumed.  For your test, try running 10,000+ of your test 
messages.  You should see a db-2.log file created and the db-1.log file 
deleted once all the messages are consumed.

See the SystemUsage configuration options for limiting the disk space 
that you want to allow AMQ to use.  A good rule of thumb is space for at 
least 3-4 days worth of data (depending on your messaging pattern).

Hope this helps!
Matt Pavlovich

On 1/24/12 1:32 PM, Abimael wrote:
> Hi
> Perhaps my question is simple . I tried to look for information on ApacheMQ
> documentaion but I 'm not able to do.
> Scenario :
>   DurableTopic configured via webadmin;
>   Persistent Messages sent by Producer with no time to live defined.
>   Consumer consumer messages deliveried assync.
>   I noticed that the Kahadb files does not change . I mean , the Kahadb files
> does not decrease.
>   I guess that the messages are kept there forever , even they are consumer
> by the Consumer.
> But I could not check such "guess" in the documentation.
>   I understand that Persistent messages are kept to avoid be lost by a broker
> outage , but I do not know if they are kept AFTER consumer consumes .
>   I am planning some disk space and I do not know if the space will increase
> indefinitely . I guess it will not, but I want to be sure and understand
> "how" it is managed.
> Thanks in advance
> --
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