ceilometer service is working on a single thread

[gordon chung]

ceilometer collector is working off a single thread. this makes processing data very slow... this explans why, we don't see any QueuePool issues because we only ever have one connection writing to the db.

***The best option is here it to spawn multiple processes. Oslo's services.py should support that, but I never took the time to work on that.***

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/79790

[Julien Danjou (jdanjou)]

Welcome to Python. Nothing is thread safe, and performances in Python of real system threads are terrible. Greenthreads that we used to be via monkey patching are introducing bugs in some drivers (like Cassandra).

The best option is here it to spawn multiple processes. Oslo's services.py should support that, but I never took the time to work on that.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/79962

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/79962
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=0f038d2fe22edacb576e2fa82e4243f229098bd0
Submitter: Jenkins
Branch: master

commit 0f038d2fe22edacb576e2fa82e4243f229098bd0
Author: Gordon Chung <email address hidden>
Date: Wed Mar 12 10:58:20 2014 -0400

    spawn multiple workers in services

    the collector service only ever grabs one connection to the
    database at a time. this causes a massive backlog on the message
    queue. enable ability to spawn multiple workers for notification
    and collector services.

    Change-Id: Ie85c4a6eace52c771c3eb8425839d253f8dd74cd
    Closes-Bug: #1291054