[rabbitmq-discuss] Form Submission - Add A Question

Fri Nov 21 23:54:30 GMT 2008

Sean,

On Fri, Nov 21, 2008 at 9:30 PM, Sean Treadway <sean at soundcloud.com> wrote:

> What qualifies as "mid-flight" and how/when does that happen?

http://lettuce.squarespace.com/faq/flow-control/what-is-a-message-in-mid-flight.html

>> This will depend in part on how your client behaves, e.g. whether it
>> absorbs socket back pressure or not.
>
> I don't believe I can control any socket options with the library I'm using.

Exactly my point. If you don't what your client is doing under the
covers, you are not in a good position to reason with the behavior of
the broker :-(

>> b) What library are you using?
>
> I'm using the result returned by Queue.Declare passive=1 from RabbitMQ 1.4.0
> using Aman's Ruby library from

Matthias has already answered this question.

> http://github.com/tmm1/amqp/commits/d2cbf1e48eacdd3a6708212ced4bc1a204d5ae21

That old chestnut :-)

> The test case that I'm basing my observations on is zipped up with
> instructions in the README.  The tests require the EventMachine gem, and
> amqp 0.5.9 or source to be installed.

OK, I'll try to have a look at this.

>> Do client A and B have their own channel or do they share a channel?
>
> A and B have different channels, they are running on separate processes.

OK

> Excellent to hear.
>
> I'm sure that Basic.Get can be used, but in my rough tests, I couldn't get
> un-ack'd messages redelivered.  I believe I was failing to close my channel
> to get them redelivered.  I'll also take another look at Basic.Get with
> no_ack=true.

http://lettuce.squarespace.com/faq/flow-control/how-long-does-it-take-to-redeliver-an-un-acknowledged-messag.html

Ben