We are using the STOMP protocol which doesn't support that. I was curious if there might be any settings server side which would help with the scalability of concurrent subscribes?
> -----Original Message----- > From: Gary Tully [mailto:gary.tu...@gmail.com] > Sent: Wednesday, May 04, 2011 5:39 PM > To: users@activemq.apache.org > Subject: Re: Scaleability problems with queue subscriptors > > have you tried to use prefetch=0 on the work queue, so the next > message will not be dispatched till you issue another receive call > rather than when the ack occurs. > > On 4 May 2011 21:29, Josh Carlson <jcarl...@e-dialog.com> wrote: > > Hi Gary, > > > > Thanks for the response. We've decided it would be easy for us to > partition our consumers such that they each consumer operates on only > one queue. However, the model we are using retrieves a message from one > queue (the job queue), then grabs something to do from another queue > (the work queue), once it retrieves the message from the work queue it > acknowledges the job queue and goes and does its work. However, since > another message is dispatched once the ack is done and the work can take > a long time (potentially infinite) we unsubscribe. Â Subsequently, once > the work is done the consumer needs to go subscribe and retrieve another > message. > > > > Switching to one queue helps when there is no or few messages. > However, it is not scaling when there are plenty of messages due to the > way we need to subscribe/unsubscribe. Do you have any suggestions on how > we might be able to scale this given our current architecture? > > > > -Josh > > > >> -----Original Message----- > >> From: Gary Tully [mailto:gary.tu...@gmail.com] > >> Sent: Friday, April 29, 2011 6:27 PM > >> To: users@activemq.apache.org > >> Subject: Re: Scaleability problems with queue subscriptors > >> > >> setting up a consumer is a little expensive, have a look at using a > >> composite destination so that you can subscribe to all destinations > at > >> once. > >> Also, there is a delay between new consumer registration and async > >> dispatch, so waiting a few seconds before unsubscribe is necessary. > >> > >> http://activemq.apache.org/composite-destinations.html > >> > >> On 28 April 2011 23:41, Josh Carlson <jcarl...@e-dialog.com> wrote: > >> > We are using a shared file system Master/Slave for the broker. > Version > >> 5.4.2. Our clients use the STOMP protocol. We use client > >> acknowledgements and communicate synchronously with the broker (using > >> receipts). We set prefetch to 1 in our subscriptions. Our clients > >> iterate over several queues, subscribing, checking for messages > (timeout > >> of 50ms), and if one isn't available it un-subscribes and goes to the > >> next queue. There are almost always cases where there are no messages > in > >> the queues. We ran into a problem where our application slowed down > to a > >> crawl when we deployed additional clients and I've narrowed it down > to > >> the fact that most of the time when we subscribed to the queue and > then > >> asked if a message was ready it wouldn't be even though there were > >> messages in the queue. My assumption is that it is taking some time > to > >> dispatch the message. > >> > > >> > Is there some configuration parameters I might want to set to help > >> with this problem? Or is this type of use just not going to scale? > >> > > >> > Here is some benchmark data. Each test, creates N consumers, but > >> before they are allowed to start it enqueues 50*N messages for the > >> consumer into *one* queue. The first set of metrics is for the case > >> where the consumers are iterating over 6 different queues (even > though > >> there is only data in one). The second set of metrics we ONLY have 1 > >> queue ... in this case the client only subscribes and un-subscribes > once > >> except in the case where a message 'isn't ready' in that 50ms (in > which > >> case it re-subscribes to the same queue). The metrics capture the > entire > >> process. getNextMessage, iterates over the queues, doing the > >> subscribes/un-subscribes, receipts etc ... > >> > > >> > Note that in the 6 queue case time degrades once you have 100 > >> consumers. In the other case it degrades after 100 but we never see a > >> Median greater than 206ms. > >> > > >> > TEST Case 6 Queues ... 5 of which are empty (note that in this > first > >> case since 5 queues are empty one expects at least 250ms to poll > those 5 > >> empty queues). Times are in seconds. > >> > > >> > Number of Consumers 1. Muliple Queues > >> > Min: 0.349334999918938 > >> > Max: 0.368788999971002 > >> > Mean: 0.350222800001502 > >> > Median: 0.349644500005525 > >> > Std Dev: 0.00271797410606451 > >> > Starting test for consumer count 10 > >> > > >> > Number of Consumers 10. Muliple Queues > >> > Min: 0.349282000097446 > >> > Max: 0.394184999982826 > >> > Mean: 0.353602201999165 > >> > Median: 0.352992500003892 > >> > Std Dev: 0.00542072612850504 > >> > Starting test for consumer count 50 > >> > > >> > Number of Consumers 50. Muliple Queues > >> > Min: 0.315161000005901 > >> > Max: 0.425882000010461 > >> > Mean: 0.360078899599938 > >> > Median: 0.359610499988775 > >> > Std Dev: 0.00788422976924438 > >> > Starting test for consumer count 75 > >> > > >> > Number of Consumers 75. Muliple Queues > >> > Min: 0.342441000044346 > >> > Max: 0.66088400001172 > >> > Mean: 0.401721995466513 > >> > Median: 0.396242500049994 > >> > Std Dev: 0.0404559664668615 > >> > Starting test for consumer count 100 > >> > > >> > Number of Consumers 100. Muliple Queues > >> > Min: 0.352722999989055 > >> > Max: 3.99510599998757 > >> > Mean: 0.563622044800525 > >> > Median: 0.494796500017401 > >> > Std Dev: 0.413950797976057 > >> > Starting test for consumer count 300 > >> > > >> > Number of Consumers 300. Muliple Queues > >> > Min: 0.361888999934308 > >> > Max: 5.53048999991734 > >> > Mean: 1.91027370266765 > >> > Median: 1.8000390000525 > >> > Std Dev: 0.489824211293863 > >> > Starting test for consumer count 600 > >> > > >> > Number of Consumers 600. Muliple Queues > >> > Min: 0.335149999940768 > >> > Max: 10.6164910000516 > >> > Mean: 4.52802392866641 > >> > Median: 4.35808100004215 > >> > Std Dev: 0.840368954779232 > >> > Starting test for consumer count 900 > >> > > >> > Number of Consumers 900. Muliple Queues > >> > Min: 0.639438000041991 > >> > Max: 18.2733670000453 > >> > Mean: 8.00563488822206 > >> > Median: 7.6759294999647 > >> > Std Dev: 1.38340937172684 > >> > Starting test for consumer count 1200 > >> > > >> > Number of Consumers 1200. Muliple Queues > >> > Min: 0.474138000048697 > >> > Max: 31.5018520000158 > >> > Mean: 12.8169781057334 > >> > Median: 12.2411614999873 > >> > Std Dev: 2.45701978986895 > >> > Starting test for consumer count 1500 > >> > > >> > Number of Consumers 1500. Muliple Queues > >> > Min: 3.1234959999565 > >> > Max: 48.7995179999853 > >> > Mean: 18.8858608815866 > >> > Median: 17.5380175000173 > >> > Std Dev: 4.1516799330252 > >> > Starting test for consumer count 1800 > >> > > >> > Number of Consumers 1800. Muliple Queues > >> > Min: 4.99818900006358 > >> > Max: 73.2436839999864 > >> > Mean: 27.1358068585671 > >> > Median: 25.4123435000074 > >> > Std Dev: 6.30049000845097 > >> > Starting test for consumer count 2400 > >> > > >> > Number of Consumers 2400. Muliple Queues > >> > Min: 0.319424999994226 > >> > Max: 114.78910699999 > >> > Mean: 46.0846290592237 > >> > Median: 44.3440699999919 > >> > Std Dev: 10.2871979782358 > >> > > >> > TEST Case only 1 queue > >> > > >> > Number of Consumers 1. Only One Queue > >> > Min: 0.0413880000123754 > >> > Max: 0.0445370000088587 > >> > Mean: 0.0416983800008893 > >> > Median: 0.041657000023406 > >> > Std Dev: 0.00042437742781418 > >> > Starting test for consumer count 10 > >> > > >> > Number of Consumers 10. Only One Queue > >> > Min: 0.0409169999184087 > >> > Max: 0.0494429999962449 > >> > Mean: 0.0419903019983321 > >> > Median: 0.0417659999802709 > >> > Std Dev: 0.000839524388489985 > >> > Starting test for consumer count 50 > >> > > >> > Number of Consumers 50. Only One Queue > >> > Min: 0.00652100006118417 > >> > Max: 0.0843779999995604 > >> > Mean: 0.0431237947992515 > >> > Median: 0.0423434999538586 > >> > Std Dev: 0.00470470800328101 > >> > Starting test for consumer count 75 > >> > > >> > Number of Consumers 75. Only One Queue > >> > Min: 0.00334199995268136 > >> > Max: 0.120109000010416 > >> > Mean: 0.0456681223996294 > >> > Median: 0.0435704999836161 > >> > Std Dev: 0.00729394094656864 > >> > Starting test for consumer count 100 > >> > > >> > Number of Consumers 100. Only One Queue > >> > Min: 0.00263900007121265 > >> > Max: 0.206331999972463 > >> > Mean: 0.051723164400761 > >> > Median: 0.0513750000391155 > >> > Std Dev: 0.0225837245735077 > >> > Starting test for consumer count 300 > >> > > >> > Number of Consumers 300. Only One Queue > >> > Min: 0.00258900003973395 > >> > Max: 1.01170199993066 > >> > Mean: 0.138241231733017 > >> > Median: 0.136385999969207 > >> > Std Dev: 0.0863229692434055 > >> > Starting test for consumer count 600 > >> > > >> > Number of Consumers 600. Only One Queue > >> > Min: 0.00214999995660037 > >> > Max: 3.27785699989181 > >> > Mean: 0.274939405133063 > >> > Median: 0.256795499997679 > >> > Std Dev: 0.237695097382708 > >> > Starting test for consumer count 900 > >> > > >> > Number of Consumers 900. Only One Queue > >> > Min: 0.00206800003070384 > >> > Max: 31.7313950000098 > >> > Mean: 0.5553230254 > >> > Median: 0.338199999998324 > >> > Std Dev: 1.14882073602057 > >> > Starting test for consumer count 1200 > >> > > >> > Number of Consumers 1200. Only One Queue > >> > Min: 0.00257100001908839 > >> > Max: 49.8629720000317 > >> > Mean: 0.912980378683317 > >> > Median: 0.393762999970932 > >> > Std Dev: 2.87091387484458 > >> > Starting test for consumer count 1500 > >> > > >> > Number of Consumers 1500. Only One Queue > >> > Min: 0.00201100006233901 > >> > Max: 74.3607440000633 > >> > Mean: 1.19311908142647 > >> > Median: 0.205018000095152 > >> > Std Dev: 4.4037236439348 > >> > Starting test for consumer count 1800 > >> > > >> > Number of Consumers 1800. Only One Queue > >> > Min: 0.00196300004608929 > >> > Max: 84.4792379999999 > >> > Mean: 1.29789674880008 > >> > Median: 0.117239500046707 > >> > Std Dev: 5.19232074252423 > >> > Starting test for consumer count 2400 > >> > > >> > Number of Consumers 2400. Only One Queue > >> > Min: 0.00200599990785122 > >> > Max: 124.155756999971 > >> > Mean: 1.77886690554984 > >> > Median: 0.101840000017546 > >> > Std Dev: 8.38169615533614 > >> > > >> > > >> > >> > >> > >> -- > >> http://blog.garytully.com > >> http://fusesource.com > > > > > > -- > http://blog.garytully.com > http://fusesource.com
