On 07/11/2015 05:52 PM, Fraser Adams wrote:
On point b. has anyone (most likely Gordon) explored the scaling limits of qpidd? Obviously when Qpid started out servers tended to have something between one and four cores, but now of course Moore's law tends to be followed by increasing the number of cores, so I'm curious as to how qpidd scales.
There hasn't really been sufficient focus on different aspects of scalability in general.
However in tests where a moderate number of connections (typically 10s, rather than 100s) transferred messages at their maximum rate, did not show significant benefit in increasing the number of worker-threads above 8 even if there were more cores available. These tests were focused on throughput and not on the number of connections, so I would always advise some benchmarking of scenarios similar to those anticipated in deployment.
I'm thinking of things like ActiveMQ Apollo where as I understand it it uses hawt-dispatch (which I think is the Java equivalent of Apple's Grand Central Dispatch pattern) and I know with Proton there has been a lot of work migrating to a more reactive pattern, which makes me wonder if that's an acknowledgement of any potential scaling limits in qpidd at present? If there are known limits is there a roadmap to change the threading model.
I think the limits are less in the threading model, which I think is a reasonable basis for scalable operation, and more in the locking and memory management.
--------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@qpid.apache.org For additional commands, e-mail: users-h...@qpid.apache.org
