Data Control Plane (a.k.a. Server Knobs)

Glean provides a Data Control Plane through which metrics can be enabled, disabled or throttled through a Nimbus rollout or experiment.

Products can use this capability to control "data-traffic", similar to how a network control plane controls "network-traffic".

This provides the ability to do the following:

  • Allow runtime changes to data collection without needing to land code and ride release trains.
  • Eliminate the need for manual creation and maintenance of feature flags specific to data collection.
  • Sampling of measurements from a subset of the population so that we do not collect or ingest more data than is necessary from high traffic areas of an application instrumented with Glean metrics.
  • Operational safety through being able to react to high-volume or unwanted data.
  • Visibility into sampling and sampling rates for remotely configured metrics.