ceilometer devstack plugin not efficient in multinode scenario

[Chris Dent]

If you want to run ceilometer via a multinode devstack setup the devstack/plugin.sh code is not well optimized to handle this: services and storage which are not required on e.g. a compute node are started. Some examples:

* if CEILOMETER_USE_MOD_WSGI evaluates to true, the api service will be started even if "disable_service ceilometer-api" has happened
* if ceilometer-collector is not enabled, the database is still created on the current node

There are probably others, but that's a start.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/238583

[ZhiQiang Fan (aji-zqfan)]

for database issue, we need to discuss how complicated we want to support,

for a simple 1 controller + X compute model, we can install according to collector service

for multiple controllers, we need to specify which node want to install database service, but I think we should not support such model for now, because I have no use case for such scenario, devstack is not a good choice for too complicated scenario I think, we have openstack-puppet and openstack-ansible for it

what's your opinion?

[Chris Dent (cdent)]

I think the right thing is keep it simple: if collector is enabled for this node, install the database, otherwise don't. While that doesn't cover all the available scenarios it does get the common ones while correcting the presenting problem (installing the database on compute only nodes).

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/238583
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=9c3278c942e07cc0f94439895cffafbe6697afbc
Submitter: Jenkins
Branch: master

commit 9c3278c942e07cc0f94439895cffafbe6697afbc
Author: ZhiQiang Fan <email address hidden>
Date: Thu Oct 22 08:37:14 2015 -0600

    configure Apache only when ceilometer-api is enabled

    Currently, even though ceilometer-api service is disabled by user,
    we still try to configure ceilometer-api in Apache if CEILOMETER_USE_MOD_WSGI
    is not set to false. This patch adds a constraint to ensure we only
    configure when ceilometer-api is enabled.

    Change-Id: I3f2bab3f646f7df57c32db3251f811cb801d93de
    Partial-Bug: #1508518

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/244191

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/244191
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=0ba0ba7270973c8a9558f863428ecefe120c9467
Submitter: Jenkins
Branch: master

commit 0ba0ba7270973c8a9558f863428ecefe120c9467
Author: ZhiQiang Fan <email address hidden>
Date: Wed Nov 11 01:15:58 2015 -0700

    install database when collector is enabled.

    Currently, if we run devstack for compute node, ceilometer-collector
    service will be disabled on compute node, but the database is still
    installed.

    This patch makes sure that database is installed only when collector
    is enabled.

    Also add check for coordinate and hypervisor requirements.

    Change-Id: Ib3614d2e698403c24ad299d95ef42c81815fa76e
    Closes-Bug: #1508518

[Thierry Carrez (ttx)]

This issue was fixed in the openstack/ceilometer 6.0.0.0b1 development milestone.