On 12/28/2010 07:00 PM, Mark Moseley wrote:
Sorry in advance that this is long. I've tried to explain it as
succinctly but thoroughly as possible.

I've got a 2-node qpid test cluster at each of 2 datacenters, which
are federated together with a single durable static route between
each. Qpid is version 0.8. Corosync and openais are stock Squeeze
(1.2.1-3 and 1.1.2-2, respectively). OS is Squeeze, 32-bit, on Dell
Poweredge 1950s, kernel 2.6.36. The static route is durable and is set
up over SSL.

This is quite possibly just a conceptual problem with how I'm setting
this up, so if anyone has a 'right way' to do it, I'm all ears :)

Just a prelim: Call them cluster A with nodes A1 and A2, and cluster B
with nodes B1 and B2. The static route is defined as A1->B1 for an
exchange on cluster B (call it exchangeB), and the other route is
B1->A1 for an exchange on cluster A (call it exchangeA). After setting
this up, things seem to work pretty well. I can send from any node in
cluster A to exchangeB and it's received by any receiving node in
cluster B. Running "qpid-config ... exchanges --bindings" on cluster A
nodes show the route to cluster B for exchangeB and vice versa. That
seems to be good.

The trouble I'm having regards failover. I'm finding that if I fail
the cluster in the order where the node with the route on it lives:

* Kill A1, kill A2, start A2, start A1  ->  The bindings on cluster B
for exchangeA get set back up automatically

Also, after I kill A1, the route seems to fail over correctly to A2,
i.e. with A1 dead and A2 still alive, looking at qpid-route on B1 or
B2 says:
Exchange 'exchangeA' (direct)
     bind [mytopic] =>  bridge_queue_1_f6d80145-67d2-4659-b26e-80c4da3ae85b

If I stop the cluster in this order:

* Kill A2, kill A1, start A1, start A2  ->  The bindings on cluster B
for exchangeA don't get set up, i.e. on B1 or B2, qpid-route says:
Exchange 'exchangeA' (direct)

Am I doing something wrong or is this a known limitation? I'd expect
that regardless of ordering, a durable route would come back up on its
own, on either node. I'd also think that if it was a limitation, it'd
happen in the other order, when A2 was the last node standing,
considering the route was created for A1.


I think you have uncovered a bug, can you create a JIRA for it and assign it to me initially? Detailed instructions on how to reproduce are greatly appreciated.

I had tried earlier to use source routes for my routing and they
seemed to do better at coming back after failover but on the source
clusters' side, the non-primary node (A2) would often blow up when
cluster B was down and a node in cluster B came back online, always
saying this in A2's qpid logs (10.1.58.3 is A1, 10.1.58.4 is A2):

2010-12-28 17:19:37 info ACL Allow id:walcl...@qpid action:create
ObjectType:link Name:
2010-12-28 17:19:37 info Connection is a federation link
2010-12-28 17:19:39 error Channel exception: not-attached: Channel 1
is not attached (qpid/amqp_0_10/SessionHandler.cpp:39)
2010-12-28 17:19:39 critical cluster(10.1.58.4:3128 READY/error) local
error 3054 did not occur on member 10.1.58.3:3369: not-attached:
Channel 1 is not)
2010-12-28 17:19:39 critical Error delivering frames: local error did
not occur on all cluster members : not-attached: Channel 1 is not
attached (qpid/a)
2010-12-28 17:19:39 notice cluster(10.1.58.4:3128 LEFT/error) leaving
cluster walclust
2010-12-28 17:19:39 notice Shut down


This also sounds like a bug, can you create a separate JIRA for it? Assign to me as well.

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