[rabbitmq-discuss] Delay delivering messages

Thu Sep 16 12:53:27 BST 2010

Hi Michael,

Killing the app is not recommended, because there may be unflushed 
buffers in the client - that may cause some messages not to be delivered 
and others to be delivered incompletely (which the broker will 
eventually drop). It is always recommended to close all the channels and 
all the connections before shutting down the application.

FWIW, RabbitMQ should detect when the socket closes (for whatever 
reason) and remove those connections pretty quickly (even if you didn't 
do a clean shutdown). I wonder why you still see the connections after 
killing the app.

Anyway, I don't see how that could interfere with the delays problem.

Rgds,
Vlad.

On 09/16/2010 09:01 AM, Michael Burns wrote:
> Hi Alex,
> Haven't had a chance to try with 2.0.0 but will do so soon.
>
> I've noticed sometimes that there are extra connections hanging about 
> on the RabbitMQ broker (using rabbitmqctl  list_connections).
> It's possible sometimes in our consumers that we are not always 
> closing the connection cleanly (sometimes people are simply killing 
> their app rather than shutting down cleanly).
>
> Could this somehow explain why we experience these delays?
>
> Cheers,
> Michael
>
> On Wed, Sep 8, 2010 at 10:46 AM, Alexandru Scvorţov 
> <alexandru at rabbitmq.com <mailto:alexandru at rabbitmq.com>> wrote:
>
>     Hi,
>
>     > Cool I'll try upgrading and see if that helps.
>
>     Any luck with 2.0.0?
>
>     Cheers,
>     Alex
>
>     On Mon, Sep 06, 2010 at 09:28:41AM +0100, Michael Burns wrote:
>     > >
>     > > When the slowdown occurs, does rabbit pick up speed a bit
>     later?  Or do
>     > > you have to restart it or something else of the sort?
>     > >
>     >
>     > Yes it will pick up speed after a bit without a server restart.
>     >
>     >
>     > >
>     > > When it occurs, does list_queues show a large number of
>     messages?  If
>     > > so, you're probably not ack'ing the messages after consuming them.
>     > >
>     >
>     > No. At the moment we're putting a very small number of messages
>     through the
>     > system. When the delay occurs I'm usually seeing one or two
>     messages on the
>     > queue. Eventually the messages will come through.
>     > Is there anything we could whilst the message is on the queue
>     that would
>     > give more information as to why it is not being delivered?
>     >
>     >
>     >
>     >
>     > >
>     > > On an unrelated note, 2.0.0 is out, so you might want to upgrade.
>     > >
>     >
>     > Cool I'll try upgrading and see if that helps.
>     >
>     > Cheers,
>     > Michael
>     >
>     >
>     > >
>     > > Cheers,
>     > > Alex
>     > >
>     > > On Fri, Sep 03, 2010 at 11:38:09AM +0100, Michael Burns wrote:
>     > > > Hi Alex,
>     > > > I ran the multicast client and am getting speeds like:
>     > > >
>     > > > sending rate: 3550 msg/s, basic returns: 0 ret/s
>     > > > recving rate: 3461 msg/s, min/avg/max latency:
>     11931197/12253891/12477030
>     > > > microseconds
>     > > >
>     > > > If I let it run for a bit then sometimes both the sending
>     and receiving
>     > > rate
>     > > > drop significantly e.g.:
>     > > >
>     > > > sending rate: 638 msg/s, basic returns: 0 ret/s
>     > > > recving rate: 628 msg/s, min/avg/max latency:
>     11788406/12363242/12735553
>     > > > microseconds
>     > > >
>     > > > Not sure if this drop is indicative of anything?
>     > > >
>     > > > We're using the java client 1.8.1, the broker is
>     rabbitmq_server-1.8.1
>     > > >
>     > > > Thanks
>     > > > Michael
>     > > >
>     > > > On Fri, Sep 3, 2010 at 9:29 AM, Alexandru Scvorţov
>     > > > <alexandru at rabbitmq.com <mailto:alexandru at rabbitmq.com>>wrote:
>     > > >
>     > > > > Hi Michael,
>     > > > >
>     > > > > > We are putting a very low volume of messages through and
>     have
>     > > sometimes
>     > > > > had
>     > > > > > to wait up to 15 minutes for a single message to be
>     delivered (at the
>     > > > > time
>     > > > > > this was the only message in the system).
>     > > > >
>     > > > > That sounds strage.  Are you up for a bit of debugging?
>     > > > >
>     > > > > Download the java client,
>     > > > > http://www.rabbitmq.com/java-client.html
>     > > > >
>     > > > > Unpack it, and run
>     > > > >  sh runjava.sh com.rabbitmq.examples.MulticastMain -x 1 -y 1
>     > > > >
>     > > > > That command will run one of our example programmes in a
>     way that
>     > > > > matches your setup: 1 producer (-x 1) and 1 consumer (-y 1).
>     > > > >
>     > > > > When I run it, I get speeds like:
>     > > > >  recving rate: 6052 msg/s, min/avg/max latency:
>     1063522/1118048/1164637
>     > > > > microseconds
>     > > > >  sending rate: 6419 msg/s, basic returns: 0 ret/s
>     > > > >
>     > > > > If you're getting similar speeds, there's probably
>     something wrong with
>     > > > > the consumers/producers.  If not, it might be something to
>     do with the
>     > > > > server.
>     > > > >
>     > > > > Could you please try it?
>     > > > >
>     > > > > Also, which version the broker and which client are you using?
>     > > > >
>     > > > > Cheers,
>     > > > > Alex
>     > > > >
>     > > > > On Fri, Sep 03, 2010 at 09:03:25AM +0100, Michael Burns wrote:
>     > > > > > Hi,
>     > > > > >
>     > > > > > We're just starting out with RabbitMQ and have a very
>     simple setup:
>     > > one
>     > > > > > queue, one producer doing a basicPublish and one
>     consumer doing a
>     > > > > > basicConsume using QueueingConsumer.
>     > > > > >
>     > > > > > For the most part it works fine however at fairly
>     regular intervals
>     > > we
>     > > > > are
>     > > > > > finding that messages remain on the queue for a
>     considerable period
>     > > > > before
>     > > > > > being delivered to the consumer.
>     > > > > >
>     > > > > > We are putting a very low volume of messages through and
>     have
>     > > sometimes
>     > > > > had
>     > > > > > to wait up to 15 minutes for a single message to be
>     delivered (at the
>     > > > > time
>     > > > > > this was the only message in the system).
>     > > > > >
>     > > > > > In all cases the messages are eventually delivered.
>     > > > > >
>     > > > > > I dont know where to start debugging this as there is
>     nothing in the
>     > > > > > RabbitMQ logs thats suggests something is going wrong -
>     could anyone
>     > > > > point
>     > > > > > me in the right direction as to what may be causing this?
>     > > > > >
>     > > > > > Many Thanks,
>     > > > > > Michael
>     > > > >
>     > > > > > _______________________________________________
>     > > > > > rabbitmq-discuss mailing list
>     > > > > > rabbitmq-discuss at lists.rabbitmq.com
>     <mailto:rabbitmq-discuss at lists.rabbitmq.com>
>     > > > > >
>     https://lists.rabbitmq.com/cgi-bin/mailman/listinfo/rabbitmq-discuss
>     > > > >
>     > > > >
>     > >
>
>
>
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