BTW AMQ-792 is now fixed - details here... http://incubator.apache.org/activemq/consumer-dispatch-async.html
so the only real pending issue so far that I'm aware of for dealing with slow consumers is AMQ-791 (spooling to disk)... http://issues.apache.org/activemq/browse/AMQ-791 Unless folks have any other use cases or requirements? On 7/3/06, James Strachan <[EMAIL PROTECTED]> wrote:
While perusing JIRA I spotted this issue again... http://issues.apache.org/activemq/browse/AMQ-688 I know its an issue close to folks at Amazon's hearts. Dealing with slow consumers is a fascinating problem for a messaging system; its quite a tricky problem :). Here's some background on the issue... http://incubator.apache.org/activemq/slow-consumers.html together with the currently supported features - to allow messages to be discarded on slow consumers using a pluggable algorithm... http://incubator.apache.org/activemq/slow-consumer-handling.html Now for all consumers we fill up prefetch buffers as quickly as possible... http://incubator.apache.org/activemq/what-is-the-prefetch-limit-for.html so there's always a buffer of messages per consumer. For non-durable topics once these messages are written to a socket they are evicted from RAM; so we already have some support for slow consumers. I wanted to start a discussion on both AMQ-688 and to see if folks had other requirements for handling slow consumers & to try decide what features & stragegies we should add next in this area. One of the first requirements folks ask for is that rather than blocking permanently the non-persistent topic engine until RAM is cleared, that at a certain threshhold we start spooling to disk. I've raised a separate JIRA issue for this specific feature request... http://issues.apache.org/activemq/browse/AMQ-791 Another issue some folks have hit in the past is that for high performance and to minimise context switches in the broker, we tend to use the current thread in the broker to dispatch to all the non-durable topic consumers so a slow/blocked consumer can appear to 'block' the producer. I've raised this issue to track that feature http://issues.apache.org/activemq/browse/AMQ-792 I just wondered if folks had any other issues or requirements with the whole slow consumers and non-durable topics they'd like to discuss? Is there any requirements we won't have covered if the above two JIRAs are fixed -- James ------- http://radio.weblogs.com/0112098/
-- James ------- http://radio.weblogs.com/0112098/
