message_id field wrong for user-defined samples

[Frédéric FAURE]

When POSTing user-defined data in Ceilometer : if we set the message_id field in the sample, the returned sample from POST contains the inserted value:

"message_id": "222222222222222"

but when requesting after on the sample, an internal message_id was generated instead:

"message_id": "53b364be-ef98-11e2-9073-080027880ca6"

Either the generated one is returned from POST or the user-defined one is taken into account and stored.
Or last option: an error is raised because the user cannot set this "internal" field.

[Frédéric FAURE (frederic-faure)]

See https://bugs.launchpad.net/ceilometer/+bug/1202689 for a similar bug.

[Frédéric FAURE (frederic-faure)]

Selected option: "the generated one is returned from POST".

If user set a message_id in the POSTed sample, it is just ignored (no error raised) and overridden by the generated value when sent into the pipeline and the generated value is returned in the samples' list too.

[Feilong Wang (flwang)]

Actually, I'm curious what's the user scenario to post the sample by themselves but don't want to provide a customized message id. Such as the sample collected by pollster stuff?

[Frédéric FAURE (frederic-faure)]

@Fei Long Wang (flwang): I'am using the V2 API and try to insert my own samples (with the POST method on /meters/my_meter) like "RAM used" I monitored on a compute instance with an agent. I should not have to set a message_id myself in this case (message_id is internally defined in only one place or with a given pattern to avoid conflicts).

[Feilong Wang (flwang)]

Got it, thanks for the clarification. BTW, may I know what kind of agent you're using :) ?

[Frédéric FAURE (frederic-faure)]

Actually it's just a "free" command in a shell: the result is extracted and POSTed to Ceilometer. It's just a test/example. It's not a real agent like with monitoring tools (Centreon, Zabbix, ...). My idea is to add some missing information in Ceilometer and then to use the same way than with other data gathered internally with pollster or notification for showing them into graphs.

[Feilong Wang (flwang)]

Frédéric FAURE, thanks for this explanation.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/39678

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/39678
Committed: http://github.com/openstack/ceilometer/commit/3e1ef16fcbdcbc0a29476867213a997063825d52
Submitter: Jenkins
Branch: master

commit 3e1ef16fcbdcbc0a29476867213a997063825d52
Author: Julien Danjou <email address hidden>
Date: Thu Aug 1 14:15:59 2013 +0200

    Return message_id in POSTed samples

    Change-Id: I93e33158ad9933bcdfc263f9f59146524d8b6824
    Fixes: bug #1202696