Joshua Kramer wrote:
Hello,
If I do something 'funny' (defined below), the qpidd disconnects the
session. What is the best way to handle this - is there a session
reconnect method, or do I create a new session? Are the qpidd and
Python objects gracefully destroyed if I create a new session?
AMQP uses a disconnect to signal significant errors, this in general is
good practice, as once you have had an error, it is better to pick back
up from a well know point.
This can be done in two ways, create a new session, or re-attach.
Note that a session and all the related state will be destroyed when the
session is terminated. The session gets terminated when it expires
(time-out since last traffic) which can
be set from anything on 0 to infinity I believe.
So there are two patterns to choose from:
- set the session time-out to 0 and recreate what you need
- set the session time-out to something reasonable for your application
and re-attach.
In both cases you need to work through through the logic to recreate the
resources you need, if you want to deal with the case that the broker
can be killed.
Definition of 'funny':
I am writing a server daemon in Python. The daemon may be run a first
time, which means it needs to create a local queue on which to listen,
and then create a server queue to which the local queue can be
subscribed. The daemon may also be run again (on the same or a
different machine to provide additional threads servicing requests),
in which case it needs to create a local queue and subscribe to the
server queue.
I am doing it in the manner: I first create a local queue and
subscribe it to a server queue. If I get a
qpid.session.SessionException, the server queue must not exist... so I
then create the server queue, create the local queue, and subscribe it
to the server queue.
I did not account for the fact that the qpidd server disconnects the
session when it can't find the server queue.
why not just declare it regardless?
Carl.
