Metrics - OpenTelemetry Metrics - Cosmos DB

[algattik]

Depends on agera-edc/DataSpaceConnector#35 (Metrics - Micrometer instrumentation and bindings)

The OpenTelemetry Metrics API has just been made stable and is the way forward for portable application metrics bindings. (The OpenTelemetry Metrics SDK, in contrast, is still in alpha, which is why we won't use it currently, and use Micrometer instead).

We will use the Cosmos DB persistence layer as a first showcase for custom metrics implementation.

• [ ] Discussion with Jim to agree on the approach and on the OpenTelemetry Metrics API library dependency. Agree on which module will declare the OpenTelemetry Metrics API dependency.
• [ ] Implement bridge code for OpenTelemetry Metrics API to Micrometer
• [ ] ADR to decide on which Cosmos DB metrics we want to collect. As inputs, check Cosmos DB SDKs for any integrated metrics (e.g. in .NET?); community input; inspiration from Micrometer JPA binding
• [ ] Implement binding with Cosmos DB SDK to collect metrics on database calls

[algattik]

We've determined that the App Insights agent already collects these on Azure, thus the scope is not needed. Closing