Monitor the Grafana Alloy component controller

The Alloy component controller exposes Prometheus metrics which you can use to investigate the controller state.

Metrics for the controller are exposed at the /metrics HTTP endpoint of the Alloy HTTP server, which defaults to listening on http://localhost:12345.

The documentation for the alloy run command describes how to modify the address Alloy listens on for HTTP traffic.

The controller exposes the following metrics:

alloy_component_controller_evaluating (Gauge): Set to 1 whenever the component controller is evaluating components. This value may be misrepresented depending on how fast evaluations complete or how often evaluations occur.
alloy_component_controller_running_components (Gauge): The current number of running components by health. The health is represented in the health_type label.
alloy_component_evaluation_seconds (Histogram): The time it takes to evaluate components after one of their dependencies is updated.
alloy_component_dependencies_wait_seconds (Histogram): Time spent by components waiting to be evaluated after one of their dependencies is updated.
alloy_component_evaluation_queue_size (Gauge): The current number of component evaluations waiting to be performed.