Hi Rob, I didn't run such a test, but I'd expect that the queue would pretty quickly fill up and block the senders using the config snippet below since it limits the queue size to 1Mb.
Colin -----Original Message----- From: Rob Davies [mailto:rajdav...@gmail.com] Sent: Monday, September 21, 2009 3:25 PM To: dev@activemq.apache.org Subject: Re: [VOTE] AciveMQ Protocol Buffers 1.0 and Apache ActiveMQ 5.3.0 releases Hey Colin - what results do you see with flow control on and no consumers for persistent queues ? On 21 Sep 2009, at 21:01, Colin MacNaughton wrote: > So ran into 2 issues running performance tests: > > 1. I ended up tweaking the default config to limit destination sizes > and > enable flow control as follows: > > <destinationPolicy> > <policyMap> > <policyEntries> > <policyEntry topic=">" producerFlowControl="true" > memoryLimit="1mb"> > > <pendingSubscriberPolicy> > <vmCursor/> > </pendingSubscriberPolicy> > </policyEntry> > <policyEntry queue=">" producerFlowControl="true" > memoryLimit="1mb"/> > </policyEntries> > </policyMap> > </destinationPolicy> > > The current default config was resulting in really high latencies in > non > persistent pub sub tests (> 2 minutes!). With the new settings > throughput > doubled and average latency dropped to 3 seconds. > > However, it seems like there is some resistance to enabling flow > control by > default: http://issues.apache.org/activemq/browse/AMQ-2318, as naïve > users > might erroneously interpret this as a hang. > > So there is a tradeoff here against guarding again naïve users and > good out > of box performance benchmarking. > > A possible compromise appropriate for the 5.3.0 release time frame > would be > to log a warning the first time flow control is triggered for a > destination, > to assist naive users in troubleshooting producer pauses. > > More long term, it might be worth introucing a more sophisticated > mechanism > for when we page to disk like only do so when there are no consumers > connected. A policy similar to this is already being pursued in the > amq 6.0 > prototype. > > I logged this as http://issues.apache.org/activemq/browse/AMQ-2400 > > 2. Fan-in to dups_ok queue receivers: > While running performance tests I I was seeing hangs in several tests > involving dups ok queue receivers. My suspicion is that this is > related to > "too lazy" dups_ok acknowledgements. Changing the queue > prefetchLimit to 100 > caused this problem to go away. This needs more investigation, but > it seems > like we can get ourselves in to trouble if the queue size is smaller > than > the receiver's prefetchLimit, and this should be avoid. It is also > possible > that there is something more complicated happening in my tests. I > haven't > yet been able to reproduce this outside my performance test > environment. > > Logged as http://issues.apache.org/activemq/browse/AMQ-2401 > > -----Original Message----- > From: Colin MacNaughton [mailto:colin.macnaugh...@gmail.com] > Sent: Friday, September 18, 2009 12:49 PM > To: dev@activemq.apache.org > Subject: RE: [VOTE] AciveMQ Protocol Buffers 1.0 and Apache ActiveMQ > 5.3.0 > releases > > Hey Dejan, > > FYI, I'm running the RC though the Progress internal performance > test suite > over the weekend. Will advise of the results, but it should be > interesting > to see how the new default config performs, and we can see if we > need to > tweak it. > > Colin > > -----Original Message----- > From: chubr...@gmail.com [mailto:chubr...@gmail.com] On Behalf Of > Dejan > Bosanac > Sent: Friday, September 18, 2009 11:14 AM > To: dev@activemq.apache.org > Subject: Re: [VOTE] AciveMQ Protocol Buffers 1.0 and Apache ActiveMQ > 5.3.0 > releases > > Ok, I'll modify tomorrow how we create source release and include > protobuf > code in it. I guess I'll need to tweak assembly-plugin and > apache-source-release-assembly-descriptor, but have to research it > more on > how to do it. If anybody has any experience with this and would > provide any > pointers it would be very helpful. > > Cheers > -- > Dejan Bosanac > > Open Source Integration - http://fusesource.com/ > ActiveMQ in Action - http://www.manning.com/snyder/ > Blog - http://www.nighttale.net > > > On Fri, Sep 18, 2009 at 7:02 PM, Hiram Chirino <chir...@gmail.com> > wrote: > >> Yeah that that does not have the source tar ball for the protobuf >> release. >> >> On Fri, Sep 18, 2009 at 12:52 PM, Bruce Snyder >> <bruce.sny...@gmail.com >>> wrote: >> >>> On Fri, Sep 18, 2009 at 7:10 AM, Hiram Chirino <chir...@gmail.com> >> wrote: >>>> Could you also post links to the source tarballs? Thanks! >>> >>> He already did: >>> >>> >>> >> > https://repository.apache.org/content/repositories/activemq-staging-030/org/ > apache/activemq/activemq-parent/5.3.0/ >>> >>> Bruce >>> -- >>> perl -e 'print >>> unpack("u30","D0G)u8...@4vyy9&5R\"F)R=6-E+G-N>61E<D\!G;6%I;\"YC;VT*" >>> );' >>> >>> ActiveMQ in Action: http://bit.ly/2je6cQ >>> Blog: http://bruceblog.org/ >>> Twitter: http://twitter.com/brucesnyder >>> >> >> >> >> -- >> Regards, >> Hiram >> >> Blog: http://hiramchirino.com >> >> Open Source SOA >> http://fusesource.com/ >> > > Rob Davies http://twitter.com/rajdavies I work here: http://fusesource.com My Blog: http://rajdavies.blogspot.com/ I'm writing this: http://www.manning.com/snyder/
