Slap.Streams.Telemetry (slap_streams v0.3.0)

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Telemetry events, all under [:slap, :streams, ...]. Slap.Streams.Metrics turns them, and slap_cluster's, into Prometheus metrics.

  • [:append, :acknowledged] - an append was acknowledged (durable). Measurements: :duration (native time units, from the stream server accepting it to the reply), :bytes. Metadata: :shard, :result (:appended or :closed).
  • [:append, :rejected] - an append was refused for backpressure. Measurements: :bytes. Metadata: :shard, :reason (:overloaded).
  • [:stream_server, :write_failed] - a write failed; the server stopped and failed its in-flight requests. Metadata: :shard.
  • [:wait, :registered] - a read with :wait (long poll or SSE) found no data and is waiting. Any append after this event wakes it. Metadata: :shard, :path, :offset (the offset it waits for).
  • [:shard, :load] - every :load_interval, per shard: the measurements of the shard's load. Metadata: :shard.
  • [:http, :request] - an HTTP response was sent. Measurements: :duration. Metadata: :method, :status.

The acknowledgement and wait events have no matching :start or :stop events.