Telemetry GenServer for the ExESDB core package.

This module is responsible only for monitoring and observability within the core ex_esdb package. It follows proper separation of concerns by:

1. Only handling telemetry events from this package
2. Running as a supervised GenServer for reliability
3. Broadcasting events through PubSub for external consumption
4. Maintaining internal metrics and health state

Responsibilities

• Monitor event store read/write operations
• Track stream operations and performance
• Monitor subscription management and delivery
• Track snapshot operations
• Monitor gateway worker performance
• Collect cluster consistency and health metrics

Usage

The telemetry server is automatically started by the ExESDB supervisor. To emit custom events from your code:

ExESDB.Telemetry.emit(:stream_write_start, %{store: :my_store, stream: "my-stream"})
ExESDB.Telemetry.emit(:stream_write_complete, %{store: :my_store, stream: "my-stream", events: 5, duration_us: 1500})

To get current metrics:

ExESDB.Telemetry.get_metrics()
ExESDB.Telemetry.get_health()