Milvex.Telemetry (milvex v0.10.2)

Telemetry events emitted by Milvex.

Milvex uses :telemetry to emit events for gRPC operations, connection lifecycle, and data encoding. You can attach handlers to these events using :telemetry.attach/4 or :telemetry.attach_many/4.

RPC Events

Emitted via :telemetry.span/3 for every gRPC call through Milvex.RPC.

[:milvex, :rpc, :start]

Emitted when a gRPC call begins.

• Measurements: %{system_time: integer()}
• Metadata:
  • :method - The RPC method atom (e.g., :insert, :search)
  • :stub - The gRPC stub module
  • :collection - The collection name (or nil if not applicable)

[:milvex, :rpc, :stop]

Emitted when a gRPC call completes successfully.

• Measurements: %{duration: integer()} (in native time units)
• Metadata: same as :start plus:
  • :status_code - The Milvus status code from the response (or nil)

[:milvex, :rpc, :exception]

Emitted when a gRPC call raises an exception.

• Measurements: %{duration: integer()} (in native time units)
• Metadata: same as :start plus:
  • :kind - The exception kind (:error, :exit, :throw)
  • :reason - The raw exception reason
  • :stacktrace - The stacktrace
  • :error_type - Normalized error classification atom with bounded cardinality, safe for use as a metric tag. One of: :connection, :grpc, :invalid, :argument, :timeout, :closed, :econnrefused, :econnreset, or :unknown

[:milvex, :rpc, :retry]

Emitted when an RPC call required retries (only if at least one retry occurred).

• Measurements: %{attempts: integer()} (number of retries, not counting the initial attempt)
• Metadata:
  • :method - The RPC method atom
  • :stub - The gRPC stub module
  • :collection - The collection name (or nil)

Connection Lifecycle Events

Emitted via :telemetry.execute/3 from Milvex.Connection.

[:milvex, :connection, :connect]

Emitted when a connection is successfully established.

• Measurements: %{}
• Metadata:
  • :host - The Milvus host
  • :port - The Milvus port

[:milvex, :connection, :disconnect]

Emitted when a connection is lost.

• Measurements: %{}
• Metadata:
  • :host - The Milvus host
  • :port - The Milvus port
  • :reason - The disconnect reason

[:milvex, :connection, :reconnect]

Emitted when a reconnection attempt starts.

• Measurements: %{}
• Metadata:
  • :host - The Milvus host
  • :port - The Milvus port
  • :retry_count - Number of retries so far
  • :delay_ms - Backoff delay before this attempt

Data Encoding Events

Emitted via :telemetry.span/3 from Milvex.Data.

[:milvex, :data, :encode, :start]

Emitted when data encoding (row-to-column conversion) begins.

• Measurements: %{system_time: integer()}
• Metadata:
  • :row_count - Number of rows being encoded
  • :field_count - Number of fields in the schema

[:milvex, :data, :encode, :stop]

Emitted when data encoding completes.

• Measurements: %{duration: integer()} (in native time units)
• Metadata: same as :start

[:milvex, :data, :encode, :exception]

Emitted when data encoding raises an exception.

• Measurements: %{duration: integer()} (in native time units)
• Metadata: same as :start plus:
  • :kind - The exception kind
  • :reason - The raw exception reason
  • :stacktrace - The stacktrace
  • :error_type - Normalized error classification atom (see RPC exception docs)

Example

:telemetry.attach_many(
  "milvex-logger",
  [
    [:milvex, :rpc, :stop],
    [:milvex, :connection, :connect],
    [:milvex, :connection, :disconnect]
  ],
  fn event, measurements, metadata, _config ->
    Logger.info("Milvex event: #{inspect(event)}, " <>
      "measurements: #{inspect(measurements)}, " <>
      "metadata: #{inspect(metadata)}")
  end,
  nil
)