This plugin is intended to be a generic admin tool for defining various realtime metrics of various sorts.

Metrics may be 'built in' ones such as the user activity metrics which are beaconed back to Moodle HQ when you register you site (online users, active users, new users, daily users), or they may be custom ones specific to your site.

In general a metric is any real time value that you might push to another service which monitors and tracks that metric over time such as a data warehouse or a tool like AWS CloudWatch.

The key architecture here is decoupling the gathering of the metrics from where those metrics are sent. This makes it easy to send metrics to more than one place, or to change cloud providers and keep consistent metrics, or if you have a fleet with various cloud providers.

The plan is to have different sources of metrics, and 3rd party plugins can define their own metrics.

Metrics may be sent to one or more different services which we call a Collector.

We currently ship with a collector for AWS Cloudwatch and an internal Moodle database collector which has no dependancies and it used as a reference implementation and to validate the metrics are working consistently with an external collectors.