APM Central Management - Ability to apply configuration to a subset of agents with same service & environment

[lucabelluccini]

Is your feature request related to a problem? Please describe.

It is possible to have multiple instances of the same service on a given environment. In some cases we want to change the setting of a subset of such instances via APM Central Management.

Describe the solution you'd like

At the moment, the only criterias are service and environment.

It would be nice to move to a tag-based approach (e.g. treat service and environment as "base" tags). On top of those 2, it would be useful to add host (or eventually other container-derived settings) or datacenter, so it would be possible to specify a set of instances/hosts. This would allow having a lot of flexibility.

E.g. tags available on a given agent: service:myservice, environment:mytest, host:myhostname, datacenter:xyz.

Describe alternatives you've considered

The workaround at the moment is to create a "fake" environment and change the name of the environment on the applications, which requires an application restart.

[felixbarny]

What if multiple configurations match a given agent? Will the configs be merged or should we ensure only one config with the best match is applied? Follow up questions are: How should configs be merged? What about conflicts? What's the priority? What defines a "best match"? What if two configs match equally well?

[lucabelluccini]

If we want priority, we could introduce an order. Please check the issue associated to this one for more details.