should try to reconnect to mongodb on ConnectionFailure

[Ionuț Arțăriși]

Ceilometer fails to start if it cannot connect to mongodb. This happens even when the mongodb service is up, but it's not responding to connections (e.g. because it's in the process of initializing a replica set).

It would be nice to have ceilometer reconnect to mongodb, the same way other services, like nova, do for rabbitmq for example.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/86609

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/86609
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=ced867e7feabe830ca193add5437f12276b9dc05
Submitter: Jenkins
Branch: master

commit ced867e7feabe830ca193add5437f12276b9dc05
Author: Ionuț Arțăriși <email address hidden>
Date: Thu Apr 10 16:25:52 2014 +0200

    reconnect to mongodb on connection failure

    Try to reconnect to mongodb when the client library raised a
    ConnectionFailure error. This is especially useful when mongodb is in
    the process of initializing a replica set and it does not respond to
    connections even though the mongodb service is up.

    Change-Id: I1818d90c135b248a28b35dc0b9f6106cf89496ab
    Closes-Bug: #1305920

[Dina Belova (dbelova)]

Fix has been already cherry-picked to the MOS 5.0.1- changes 'Reconnect to MongoDB on connection failure' and 'Fix options placement for the MongoDB reconnect' in the 5.0.1 ceilometer MOS branch.