Open Stack

>You can deploy several ceilometer and use several databases, or just one and use a different 'source' field for each of your region/cluster to differentiate where meters come from.

Let's say if you deploy one ceilometer instance for two swift clusters 'swift-cluster-1' and 'swift-cluster-2'. According to the design, if we use 'source' field for region/cluster to tell what cluster the meters come from. The Ceilometer API doesn't seem being well thought through yet.

A single region case:
If you want to get the meters for TenantA, this API will simply do the job:
GET /v1/projects/(project)/meters/(meter)

Two regions case:
If you want to get the meters for TenantA from 'swift-cluster-1' specifically.  According to the API design we have now, there is no API can do that directly unless you do some complex API calls combination.

Shengjie