Observability

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Squid Mesh emits baseline telemetry and structured logs around run and step lifecycle events.

Telemetry Events

All events are emitted under the [:squid_mesh, ...] prefix.

Run lifecycle:

  • [:squid_mesh, :run, :created]
  • [:squid_mesh, :run, :replayed]
  • [:squid_mesh, :run, :dispatched]
  • [:squid_mesh, :run, :transition]

Step lifecycle:

  • [:squid_mesh, :step, :started]
  • [:squid_mesh, :step, :skipped]
  • [:squid_mesh, :step, :completed]
  • [:squid_mesh, :step, :failed]
  • [:squid_mesh, :step, :retry_scheduled]

Common Metadata

Run events include:

  • run_id
  • workflow
  • trigger
  • status
  • current_step

Run dispatch events also include:

  • job_id
  • queue
  • schedule_in

Run transition events also include:

  • from_status
  • to_status

Step events include:

  • run_id
  • workflow
  • trigger
  • status
  • current_step
  • step
  • attempt

Step failure events also include:

  • error

Step skip events also include:

  • reason

Measurements

All events include system_time.

Additional measurements:

  • step completion and failure events include duration
  • retry scheduling events include delay_ms

duration is emitted in native time units.

For ordinary step execution, duration is measured from System.monotonic_time/0 within the executing worker. For paused-step completion or failure, the terminal event can happen later during unblock or cancellation, so duration is derived from the persisted attempt start timestamp instead.

That means a paused manual step such as :pause or approval_step/2 emits:

  • step.started when the pause step is first executed
  • step.completed later during unblock_run/2, approve_run/3, or reject_run/3, or step.failed if the paused run is cancelled

The terminal event still refers to the original running attempt, but its duration spans the full paused interval rather than only the worker execution window.

Structured Logs

Squid Mesh sets logger metadata for step execution so failure logs carry:

  • run_id
  • workflow
  • step
  • attempt

This metadata is attached in the step execution path so host applications can route or format logs with run-oriented context without parsing message strings.