Thats the problem - persistent Queue with no subscribers shouldn't
block until store limit is reached - this is why flow control has been
disabled by default now
On 21 Sep 2009, at 23:29, Colin MacNaughton wrote:
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
--
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\"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/
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/
