Support Elastic APM

[cah-andrew-fitzgerald]

Elastic (Elasticsearch/Kibana) is working on a new APM solution.
It would be nice if it worked out of the box with micrometer.

see elastic/apm-agent-java#112

[jkschneider]

Currently no spec has been produced by Elastic, so pushing this to 1.2.0.

[felixbarny]

A spec of the API is here: https://www.elastic.co/guide/en/apm/server/current/metricset-api.html and here: https://github.com/elastic/apm-server/blob/master/docs/spec/metricsets/metricset.json

Note that it currently only supports counters and gauges.

[jkschneider]

Thanks @felixbarny. Counters and gauges are good enough. Timers are just composed of a series of counters and gauges. We can make it work.

[felixbarny]

See also my very rough WIP for the agent-internal metric tracking here: elastic/apm-agent-java#360

[sabareeshkkanan]

This will be a great future. When can we expect this

[surenraju-zz]

This feature will be very useful.

[felixbarny]

We're also thinking about automatically adding a micrometer Collector via the Elastic APM Java agent which reports to the APM Server if the agent is attached - so that no code changes are necessary.

See also elastic/apm-agent-java#893

[ngotzmann]

Hello,
are there any news on this feature?

[xeraa]

The APM agent has a Micrometer integration in beta now: https://www.elastic.co/guide/en/apm/agent/java/current/metrics.html#metrics-micrometer

[shakuzen]

It sounds like deferring to the Micrometer support in the agent is a good resolution to this request. We can add some documentation to https://micrometer.io/docs/registry/elastic referring to the APM docs. I have made micrometer-metrics/micrometer-docs#203 for that.