I’m confused by something. Why don’t messages pile up in advisory topics? Topics only deliver messages to consumers who are actually listening I assume?
On Sat, May 2, 2015 at 2:07 PM, Kevin Burton <bur...@spinn3r.com> wrote: > I’m sorry.. this is N^2 because the Timer just keeps growing for every new > queue and they need to be purged and it has to evaluate each one. > > On Sat, May 2, 2015 at 1:40 PM, Kevin Burton <bur...@spinn3r.com> wrote: > >> Also, while this is a small performance boost in my example, this should >> have a massive impact when running with large queues. It’s calling >> Timer.purge() on each queue GC and if you have a lot of queues you’re going >> to have a lot of TimerTasks so this is a O(N). It also holds a global lock >> during this operation so no new queues can be created during a queue GC. >> >> On Sat, May 2, 2015 at 12:23 PM, Kevin Burton <bur...@spinn3r.com> wrote: >> >>> I’m doing a bunch of performance analysis of ActiveMQ this weekend to >>> see if I can improve queue creation and destruction time. The good news is >>> that there are a lot of areas of optimization. >>> >>> It looks like one is that advisory topics are created with the default >>> expireMessagesPeriod (which is 30000). However, no advisory messages are >>> produced with TTLs. >>> >>> I believe this is done in AdvisoryBroker.fireAdvisory >>> >>> … looking at this code, a TTL isn’t set. So I think that it would be a >>> good idea to enable expireMessagesPeriod=0 for advisory topics. >>> >>> Here’s the code if you’re interested: >>> >>> http://pastebin.com/i3hXDGEW >>> >>> Looks like the following policyEntry works as a proof of concept. >>> >>> <policyEntry topic=">" >>> prioritizedMessages="false" >>> useCache="false" >>> maxBrowsePageSize="2147483647" >>> expireMessagesPeriod="0"> >>> >>> </policyEntry> >>> >>> (I am going to constrain it for advisory topics though). >>> >>> In my test time time for GCing all my queues went from 45s to 17s. It’s >>> MUCH higher than this under production load though due threading issues. >>> >>> Are there any potential issues I might be missing here? >>> >>> If this works I might try to submit a patch to disable >>> expireMessagesPeriod by default for advisory topics. >>> >>> -- >>> >>> Founder/CEO Spinn3r.com >>> Location: *San Francisco, CA* >>> blog: http://burtonator.wordpress.com >>> … or check out my Google+ profile >>> <https://plus.google.com/102718274791889610666/posts> >>> >>> >> >> >> -- >> >> Founder/CEO Spinn3r.com >> Location: *San Francisco, CA* >> blog: http://burtonator.wordpress.com >> … or check out my Google+ profile >> <https://plus.google.com/102718274791889610666/posts> >> >> > > > -- > > Founder/CEO Spinn3r.com > Location: *San Francisco, CA* > blog: http://burtonator.wordpress.com > … or check out my Google+ profile > <https://plus.google.com/102718274791889610666/posts> > > -- Founder/CEO Spinn3r.com Location: *San Francisco, CA* blog: http://burtonator.wordpress.com … or check out my Google+ profile <https://plus.google.com/102718274791889610666/posts>
