I'm not sure if it would be the prefetch size. The memory usage rightly goes up when the consumer stops ack'ing messages. The question is, why does it never go back down when the consumer disconnects?
Also, I think changing the message cursor strategy would only prolong the time between failures. Yes, we could start caching messages to disk, but I would like to know why the messages don't get cleaned up from memory when the consumers disconnect (cleanly or not). -Kirby -----Original Message----- From: Bruce Snyder [mailto:[EMAIL PROTECTED] Sent: Tuesday, December 02, 2008 7:52 AM To: users@activemq.apache.org Subject: Re: Broker not releasing memory On Mon, Nov 24, 2008 at 7:37 AM, Frugia, Kirby A <[EMAIL PROTECTED]> wrote: > Hi All, > > Sorry I dual-posted in the dev list. I think I sent to the wrong one... > > We are seeing an issue with our broker not releasing memory on topics. > > Setup: > * Active MQ 5.1 (out of the box) > * Persistent messages sent by publishers > * Non-durable topics > > We were seeing an issue in production with slow consumers causing the broker > to run out of memory. > > We wrote a test app, which has one publisher and one subscriber to the same > topic. The publisher sends messages on this topic frequently. The > subscriber, upon receiving a message, goes to sleep for 10 minutes. > > Very quickly, the broker runs out of memory. When this happens, our > publishers can no longer send messages; the send is blocked. This is > expected. However, if we kill our application (which cleanly disconnects > from the broker), the broker's memory usage (MemoryPercentUsage) does not go > back down. Also, any new apps that startup will have their publishers > blocked. > > Shouldn't the broker release the memory associated with these messages? The first thing to do is configure the prefetch buffer for the client?: http://activemq.apache.org/what-is-the-prefetch-limit-for.html See how that affects the situation. If you're still experiencing issues, you might need to consider using a different message cursor strategy: http://activemq.apache.org/message-cursors.html Bruce -- perl -e 'print unpack("u30","D0G)[EMAIL PROTECTED]&5R\"F)R=6-E+G-N>61E<D\!G;6%I;\"YC;VT*" );' Apache ActiveMQ - http://activemq.org/ Apache Camel - http://activemq.org/camel/ Apache ServiceMix - http://servicemix.org/ Blog: http://bruceblog.org/
