MatchMakerRedis doesn't work [zeromq]

[fetahi]

I was testing zeromq with redis. I installed all packages from ubuntu cloud repository[havana]. I added the following lines in nova.conf.
...
rpc_zmq_matchmaker = nova.openstack.common.rpc.matchmaker_redis.MatchMakerRedis
rpc_backend = nova.openstack.common.rpc.impl_zmq
...

I get the following error
2014-03-11 09:57:58.671 11201 ERROR nova.openstack.common.threadgroup [-] Command # 1 (SADD scheduler.ubuntu scheduler.ubuntu.ubuntu) of pipeline caused error: Operation against a key holding the wrong kind of value

The same error is reported in the following services:
nova-conductor
nova-consoleauth
nova-scheduler

The problem seems to come from the matchmaker using the same key to register a set of hosts and the hosts themselves.

[Mark McLoughlin (markmc)]

This should probably be an oslo.messaging bug report only now

I don't really have any insight as to whether there's a real bug here, but it sounds plausible so marking Confirmed

[Rohit Karajgi (rohitk)]

I'm not sure what the exact cause of your errors is.
But since the time the ZMQ drivers were moved to Oslo,
your nova.conf should be configured for ZMQ as follows:

rpc_backend = nova.openstack.common.rpc.impl_zmq
rpc_zmq_matchmaker = oslo.messaging_drivers.matchmaker.MatchMakerRedis

[Li Ma (nick-ma-z)]

The enabling of zeromq in nova should be:

rpc_backend = zmq
rpc_zmq_matchmaker = oslo.messaging_drivers.matchmaker.MatchMakerRedis

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/142651

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/142651
Committed: https://git.openstack.org/cgit/openstack/oslo.messaging/commit/?id=8eed6bbd0953585353a4128112ba98ea99480c0c
Submitter: Jenkins
Branch: master

commit 8eed6bbd0953585353a4128112ba98ea99480c0c
Author: zhangjl <email address hidden>
Date: Wed Dec 17 16:04:14 2014 +0800

    Make sure zmq can work with redis

    In ZmqDriver's listen method, it calls create_consumer
    three times. After the first call, the keys related to this
    topic in redis reads like this:
      "topic": set(["topic.host"])
      "topic.host": ""

    If the second call, it tries to add the following keys:
      "topic.host": set(["topic.host.host"])
      "topic.host.host": ""

    But the key "topic.host" already exists as a string type.
    So the error occurs.

    To resolve this problem, change the value of keys from string
    to set.

    Change-Id: Ic801393d492d2656fcfd8b87f1d2efc6ab3bbd62
    Closes-Bug: #1290772