Use external tagging for metrics serialization

We’ve improved the serialized structure of our metrics events. This change should only affect a very small, and rare, number of users. If you are consuming metrics data from Vector’s console sink then you’ll need to adjust any downstream systems to work with the new structure.

For example, previously a counter was serialized like:

{
  "name": "login.count",
  "timestamp": "2019-11-01T21:15:47+00:00",
  "kind": "absolute",
  "tags": {
    "host": "my.host.com"
  },
  "value": {
    "type": "counter", // <-- metric type
    "value": 24.2
  }
}

It now serialized like:

{
  "name": "login.count",
  "timestamp": "2019-11-01T21:15:47+00:00",
  "kind": "absolute",
  "tags": {
    "host": "my.host.com"
  },
  "counter": {
    // <-- metric type
    "value": 24.2
  }
}

Upgrade Guide

Upgrading should involve handling changes in any systems that are consuming metrics data from the console sink.