different behavior of alarm creation on different DB backend

[Lianhao Lu]

Currently, we see different user experience on different DB backend when creating alarms.

On sqlalchemy, due to the foreign key constraints, an alarm can only be created if the corresponding user_id and project_id are existed in the DB, which means the alarm can NOT be created until a metering sample with the same user_id and project_id has been recorded in the DB.

However, on mongoDB, there is no such restriction. The alarm can be created whenever the user wants.

We should make different DB backends behave the same way.

method 1: drop sql foreign key constraints
method 2: in sqlalchemy implementation of alarm creation, create new user_id/project_id, just like what we does now in record_metering_data.

[gordon chung (chungg)]

a heads up, if you drop foreign key constraints, you may need to update clear_expired_metering_data since i check for that there too.

[Mehdi Abaakouk (sileht)]

The real sql error on alarm is described and fixed here: https://bugs.launchpad.net/ceilometer/+bug/1260776

But this is only one part of this issue:

My resume for second part:

The storage API layer have method get_user/get_project used only by ceilometer API v1 (the deprecated one)
What user and project is for API V1 ?
a list of all user/project in ceilometer (1) or a list of user/project of samples (2) ?
Or we don't care this is V1 API only (3) ? and for the 'foreign key constraints' of sql backend is implementation detail of this storage driver.

So the API V1 documentation says : "Return a list of all known user names.", that means mongo driver go wrong, sql go right.

BUT for me, we have a 3° solutions: Remove the API V1 and put the 'foreign key' question into a sql detail implementation.
WDYT ?

[Lianhao Lu (lianhao-lu)]

see patch https://review.openstack.org/65018 for the fixing

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/65018
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=ecbe240e6b6ef962ea0ca263c197243643e6964b
Submitter: Jenkins
Branch: master

commit ecbe240e6b6ef962ea0ca263c197243643e6964b
Author: Lianhao Lu <email address hidden>
Date: Mon Jan 6 10:53:00 2014 +0800

    Drop foreign key contraints of alarm in sqlalchemy

    This patch drops the foreign key constraints of alarms to user_id and
    project_id in sqlalchemy.

    Closes-Bug: 1260176
    Change-Id: I7336ee1e3f885421db5aae3a30af0e918b79450b