Comment 7 for bug 1243251

Reviewed: https://review.openstack.org/63424
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=64bc862f6fa936dbe5dd2d402240a81da40bc5a5
Submitter: Jenkins
Branch: master

commit 64bc862f6fa936dbe5dd2d402240a81da40bc5a5
Author: Mehdi Abaakouk <email address hidden>
Date: Fri Dec 20 15:07:39 2013 +0100

    Ensure we are not exhausting the sqlalchemy pool

    Because of eventlet, notification messages can be consumed more quickly
    that than they are wroted to the database, this have to effect to exhaust
    the sqlalchemy connection pool and raise:

    TimeoutError: QueuePool limit of size 5 overflow 10 reached, connection
    timed out, timeout 30

    The patch creates a eventlet pool to ensure that the pool never exhausts
    and prints a warning message in the log to inform that perhaps the pool
    size need to be increased.

    Fixes bug #1243251

    Change-Id: I5ccdc141c441db32fab361783a31a96015516878