Out of curiosity, which slow consumer strategy did you configure? On Wed, Mar 11, 2015 at 11:45 AM, Kevin Burton <bur...@spinn3r.com> wrote:
> The problem is that this is happening in production but not locally. > > Setting prefetchPolicy to zero fixed it for one of our tasks, but another > one of our tasks is still waiting for work and I can’t figure out why. > > It has 6000 consumers / threads, 200k messages waiting to be processed, but > none are being executed. > > The workers themselves are all waiting for ActiveMQ to send the messages. > > And none of our connections are marked slow (I think, still verifying but > it takes forever). > > On Wed, Mar 11, 2015 at 5:33 AM, Tim Bain <tb...@alumni.duke.edu> wrote: > > > I'd definitely set breakpoints and step through with a debugger to try to > > figure out what's going on. > > On Mar 10, 2015 8:19 PM, "Kevin Burton" <bur...@spinn3r.com> wrote: > > > > > This is exceedingly bizarre. Now ActiveMQ is refusing to deliver ANY > > > messages to my workers. > > > > > > This is very bizarre, no code has changed. Nothing. It’s just > refusing > > to > > > give work. > > > > > > If I set the prefetch to 0 or 1, it does work for a few moments, then > > > halts. > > > > > > 99% certain I’m committing all my messages. As it would make sense > that > > > nothing could be processed after that of course. > > > > > > Kevin > > > > > > > > > On Tue, Mar 10, 2015 at 6:53 PM, Tim Bain <tb...@alumni.duke.edu> > wrote: > > > > > > > If you make a single consumer, you'll only get one message at a time > by > > > > default (so only one thread will be doing any work). You'd have to > use > > > > client acknowledgement or selective acknowledgement to get more than > > one > > > > message at a time. I'd probably leave many consumers but tune down > > your > > > > prefetch buffers to something relatively small to ensure that the > > > workload > > > > is evenly spread and you don't have some consumers with a large > > prefetch > > > > buffer worth of backlog while others sit around idle. > > > > > > > > But if you're seeing the broker report pending messages, then that > > means > > > > that having unbalanced workloads due to large prefetch buffers isn't > > your > > > > problem... Pending messages on the broker only occur when those > > messages > > > > can't be dispatched to any consumer because all of their prefetch > > buffers > > > > are full, which would mean that you don't have unbalanced workloads. > > > > You'll get one or the other, not both. > > > > > > > > On Tue, Mar 10, 2015 at 7:42 PM, Kevin Burton <bur...@spinn3r.com> > > > wrote: > > > > > > > > > I’m actually wondering if this is my issues. I’m creating one > session > > > per > > > > > thread. So perhaps some of the threads have work to do, but > they’re > > > each > > > > > prefetching a bunch of work when in reality a better strategy might > > the > > > > to > > > > > have one master listener and then dispatch messages to each thread. > > > > > > > > > > On Tue, Mar 10, 2015 at 6:37 PM, Kevin Burton <bur...@spinn3r.com> > > > > wrote: > > > > > > > > > > > OK. That’s good to know. I have a large number of connections > so > > I > > > > have > > > > > > to look at each one. I wonder if this could also be the issue. > > AKA > > > > too > > > > > > many connections. > > > > > > > > > > > > On Tue, Mar 10, 2015 at 6:19 PM, Tim Bain <tb...@alumni.duke.edu > > > > > > wrote: > > > > > > > > > > > >> You should be able to confirm that the prefetch buffers are > empty > > by > > > > > >> inspecting the JMX MBeans on the broker. Look at the consumers > > for > > > > the > > > > > >> destination, and for each one look at its DispatchedQueueSize > > > > attribute. > > > > > >> > > > > > >> Keep in mind that slow consumers are identified *ONLY* if you > > > > configure > > > > > >> one > > > > > >> of the abort strategies. If you didn't set that up, don't > expect > > > any > > > > > slow > > > > > >> consumer identification log lines. And if you did, I've never > > seen > > > a > > > > > >> situation where a consumer went slow and a log line didn't > happen > > > > (using > > > > > >> the SlowConsumerAbortStrategy; I haven't used > > > > > SlowAckConsumerAbortStrategy > > > > > >> and can't vouch for it); we get those log lines pretty > frequently. > > > So > > > > > if > > > > > >> you're not seeing broker-side log lines about consumers being > > > > identified > > > > > >> as > > > > > >> slow and then aborted, I'd bet it's simply not happening. > > > > > >> > > > > > >> On Tue, Mar 10, 2015 at 7:10 PM, Kevin Burton < > bur...@spinn3r.com > > > > > > > > wrote: > > > > > >> > > > > > >> > The broker. I’ll assume the prefetch brokers are empty. I’m > > > looking > > > > > >> into > > > > > >> > debugging that now but I don’t have tools to introspect. > > > > > >> > > > > > > >> > The broker has thousands of messages. > > > > > >> > > > > > > >> > I just confirmed that a restart DOES improve the situation. > > > > > >> > > > > > > >> > It’s possible that they’re being marked as slow consumers but > > not > > > > > >> *logged* > > > > > >> > as such so I’m trying to use JMX to dump the sessions. > > > > > >> > > > > > > >> > On Tue, Mar 10, 2015 at 5:58 PM, Tim Bain < > > tb...@alumni.duke.edu> > > > > > >> wrote: > > > > > >> > > > > > > >> > > Are the messages getting hung up in the broker or in the > > client? > > > > > (Do > > > > > >> the > > > > > >> > > consumers have empty or full prefetch buffers?) > > > > > >> > > > > > > > >> > > On Tue, Mar 10, 2015 at 6:47 PM, Kevin Burton < > > > bur...@spinn3r.com > > > > > > > > > > >> > wrote: > > > > > >> > > > > > > > >> > > > I’m still trying to track down some issues with ActiveMQ … > > > > > >> > > > > > > > > >> > > > One is that I have 5 ActiveMQ servers now, and each one > has > > > > about > > > > > >> 3000 > > > > > >> > > > messages pending. So 15000 messages in queues. > > > > > >> > > > > > > > > >> > > > These are non-persistent queues, plenty of memory and > plenty > > > of > > > > > CPU, > > > > > >> > but > > > > > >> > > > the workers are just blocked waiting to receive work. > > > > > >> > > > > > > > > >> > > > I had a hypothesis that this could be slow workers, but > > after > > > > > tuning > > > > > >> > some > > > > > >> > > > things I no longer receive any errors about slow workers. > > > > > >> > > > > > > > > >> > > > Restarting the daemons doesn’t fix things either. > Anything > > > else > > > > > it > > > > > >> > could > > > > > >> > > > be? I’m a bit stumped unfortunately. > > > > > >> > > > > > > > > >> > > > -- > > > > > >> > > > > > > > > >> > > > 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> > > > > > >> > > > <http://spinn3r.com> > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > > >> > > > > > > >> > -- > > > > > >> > > > > > > >> > 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> > > > > > >> > <http://spinn3r.com> > > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > > > > 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> > > > > > > <http://spinn3r.com> > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > > 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> > > > > > <http://spinn3r.com> > > > > > > > > > > > > > > > > > > > > > -- > > > > > > 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> > > > <http://spinn3r.com> > > > > > > > > > -- > > 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> > <http://spinn3r.com> >
