[Hawkular-dev] what to name metrics in HOSA?

[John Mazzitelli]

> We are talking about the metrics name when stored in Hawkular Metrics,
> correct ?

Yes, these will end up as part of the H-Metric names (HOSA does allow the user to define their own IDs if they don't like the metric names coming from the resource, but the name of the metric is the default and for Prometheus endpoints people will probably use them and not define their own IDs).

> With multiple agents,I guess we would need some kind of isolation with a
> prefix or tags or tenant or else ? What options do we have ?

We do use tenants - by default we set a metric's tenant to the same as the name of the OpenShift project where that metric came from. You can see that here:

https://github.com/hawkular/hawkular-openshift-agent/blob/master/deploy/openshift/hawkular-openshift-agent-configmap.yaml#L12

And we already support an ID prefix. As you say, this is to isolate metric names in order to avoid name clashes across pods. You can see we set this in the default agent config to:

   metric_id_prefix: pod/${POD:uid}/custom/

See: https://github.com/hawkular/hawkular-openshift-agent/blob/master/deploy/openshift/hawkular-openshift-agent-configmap.yaml#L16

So, for example, if the agent is running in a pod that has a UID of "deadbeef123456" then the metric will be stored in H-Metrics as:

   pod/deadbeef123456/custom/hawkular_openshift_agent_metric_data_points_collected_total

It's tenant will be that of the project (aka namespace) of where the agent is running (which will be "openshift-infra" today).

> 
> How do we avoid clashes between 2 HOSA ?

By using this metric ID prefix. As I understand it, pod UIDs are unique across nodes so the use of ${POD:uid} avoids clashes.