Comment 1 for bug 1419718

Reviewed: https://review.openstack.org/155673
Committed: https://git.openstack.org/cgit/openstack/oslo.messaging/commit/?id=e8def40a4149651b69d0ed8fa1bdbbb431912f27
Submitter: Jenkins
Branch: master

commit e8def40a4149651b69d0ed8fa1bdbbb431912f27
Author: joyce <email address hidden>
Date: Fri Feb 13 16:21:30 2015 +0800

    Fix matchmaker_redis ack_alive fails with KeyError

    Fix matchmaker_redis: ack_alive fails with KeyError on re-registration
    attempt.

    def ack_alive(self, key, host):
        topic = "%s.%s" % (key, host)
        if not self.redis.expire(topic, CONF.matchmaker_heartbeat_ttl):
            # If we could not update the expiration, the key
            # might have been pruned. Re-register, creating a new
            # key in Redis.
            self.register(self.host_topic[host], host)

    self.host_topic is a dict with keys of tuple (key, host), not 'host',
    register's first parameter is the topic like 'notification-info',
    so modify it to key.
    And it will not cause indefinite recursion, because when register end,
    the key exist in redis, redis.expire will return True.

    Add test case for ack_alive.

    Closes-Bug: #1419718

    Change-Id: I8d972afe89aec02a5c8f0d9dd4e216bc12c298a1