api-workers does not follow the same pattern as other charms with worker-multiplier

[Xav Paice]

For Ceilometer, the default number of workers is 1, causing API problems. We suggest that this be changed to use the same worker-multiplier pattern as other charms.

[James Page (james-page)]

Hi Xav

I had a quick poke at a Pike deployment I had up; for Ocata and later releases, the ceilometer API runs under WSGI, where we use the standard worker contexts which do configure workers based on the number of cores detected; however you are quite correct in that the charm does not have a worker-multiplier configuration option - it has an api-workers config option with is foobar and misaligned.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/537813

[James Page (james-page)]

https://review.openstack.org/#/c/537813/

[James Page (james-page)]

Also worth noting that at Queens, there is no Ceilometer API so this new configuration option only effects notification and collector worker configuration options.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/537813
Committed: https://git.openstack.org/cgit/openstack/charm-ceilometer/commit/?id=b7a329d456c3b4972e7ecb79ed571230de2215f0
Submitter: Zuul
Branch: master

commit b7a329d456c3b4972e7ecb79ed571230de2215f0
Author: James Page <email address hidden>
Date: Thu Jan 25 09:35:08 2018 +0000

    Align worker configuration option

    Align ceilometer charm with worker-multiplier usage as found
    across the majority of OpenStack Charms. Worker configuration
    values are set for API, Notification and Collector services
    as needed for each release. Note that for Ocata or later, API
    services are executed as WSGI apps under Apache which was
    already plugged into the standard worker calculation logic
    in charm helpers.

    This includes dropping of the existing api-worker configuration
    option in preference to a calculated approach.

    Change-Id: Idba7c3012d9d24b7ae6ef8eade4a5261ef1cbddc
    Closes-Bug: #1745189