Comment 2 for bug 1260176

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 ?