There's a certain amount of RAM usage for the broker itself, then a bit per destination used (as there are various data structures to deal with connections, consumers, destinations etc) but they are fairly lightweight. Then the broker tends to keep around a number of messages in RAM as they are being dispatched to consumers.
Given the nature of GC, its always best you try running your application and monitoring the heap over time to get a feel for what the memory requirements are as its dependent on many factors (OS, JVM, message volume/distribution, number of destinations & connections etc One thing to be wary of in relatively low RAM environments for the broker is prefetch configurations for connections... http://activemq.apache.org/what-is-the-prefetch-limit-for.html you probably wanna set that to something small (like 1) to avoid connections & the broker keeping too many messages around. i.e. trading slower performance for lower RAM usage. Also be wary of slow consumers causing the broker to hang http://activemq.apache.org/slow-consumer-handling.html Generally speaking for high volume brokers - we recommend lots more RAM than 10MB (we tend to default to 512MB for a stand alone broker JVM) - but if you have a relativley low volume broker you might be able to get away with just 10MB - but I'd try it out and monitor actual RAM usage under typical traffic peaks first. On 2/8/07, eccrowe <[EMAIL PROTECTED]> wrote:
Greetings, I apologize in advance if this question has already been asked before, but my forum search has not been fruitful in regards to this question as of yet. The question I have is about the memory usage requirements with a non-persistent topic. We are running ActiveMQ 4.0-RC2 in an embedded environment where most memory available on the system has been pre-allocated to various processes including our JVM (128 MB). The broker memory manager has been setup such that its limit is at 10MB. I believe that the entirety of this 10MB is included within our JVM, but would appreciate a confirmation on that suspicion. Stated a different way, is there any RAM that must be allocated outside of the JVM for a topic consumer to be able to adequately receive messages? Will a consumer possibly stop receiving messages altogether if there was adequate memory pre-allocated to the JVM but not outside of its virtual machine? Many thanks in advance. -- View this message in context: http://www.nabble.com/ActiveMQ-Topic-Memory-Usage-Requirements-tf3191331s2354.html#a8859459 Sent from the ActiveMQ - User mailing list archive at Nabble.com.
-- James ------- http://radio.weblogs.com/0112098/
