defmodule Bandit.Telemetry do
@moduledoc """
The following telemetry spans are emitted by bandit
## `[:bandit, :request, *]`
Represents Bandit handling a specific client HTTP request
This span is started by the following event:
* `[:bandit, :request, :start]`
Represents the start of the span
This event contains the following measurements:
* `monotonic_time`: The time of this event, in `:native` units
This event contains the following metadata:
* `telemetry_span_context`: A unique identifier for this span
* `connection_telemetry_span_context`: The span context of the Thousand Island `:connection`
span which contains this request
* `conn`: The `Plug.Conn` representing this connection. Not present in cases where `error`
is also set and the nature of error is such that Bandit was unable to successfully build
the conn
This span is ended by the following event:
* `[:bandit, :request, :stop]`
Represents the end of the span
This event contains the following measurements:
* `monotonic_time`: The time of this event, in `:native` units
* `duration`: The span duration, in `:native` units
* `req_header_end_time`: The time that header reading completed, in `:native` units
* `req_body_start_time`: The time that request body reading started, in `:native` units.
* `req_body_end_time`: The time that request body reading completed, in `:native` units
* `req_body_bytes`: The length of the request body, in octets
* `resp_start_time`: The time that the response started, in `:native` units
* `resp_end_time`: The time that the response completed, in `:native` units
* `resp_body_bytes`: The length of the response body, in octets. If the response is
compressed, this is the size of the compressed payload as sent on the wire
* `resp_uncompressed_body_bytes`: The length of the original, uncompressed body. Only
included for responses which are compressed
* `resp_compression_method`: The method of compression, as sent in the `Content-Encoding`
header of the response. Only included for responses which are compressed
This event contains the following metadata:
* `telemetry_span_context`: A unique identifier for this span
* `connection_telemetry_span_context`: The span context of the Thousand Island `:connection`
span which contains this request
* `conn`: The `Plug.Conn` representing this connection. Not present in cases where `error`
is also set and the nature of error is such that Bandit was unable to successfully build
the conn
* `error`: The error that caused the span to end, if it ended in error
The following events may be emitted within this span:
* `[:bandit, :request, :exception]`
The request for this span ended unexpectedly
This event contains the following measurements:
* `monotonic_time`: The time of this event, in `:native` units
This event contains the following metadata:
* `telemetry_span_context`: A unique identifier for this span
* `connection_telemetry_span_context`: The span context of the Thousand Island `:connection`
span which contains this request
* `conn`: The `Plug.Conn` representing this connection. Not present in cases where `error`
is also set and the nature of error is such that Bandit was unable to successfully build
the conn
* `kind`: The kind of unexpected condition, typically `:exit`
* `exception`: The exception which caused this unexpected termination
* `stacktrace`: The stacktrace of the location which caused this unexpected termination
## `[:bandit, :websocket, *]`
Represents Bandit handling a WebSocket connection
This span is started by the following event:
* `[:bandit, :websocket, :start]`
Represents the start of the span
This event contains the following measurements:
* `monotonic_time`: The time of this event, in `:native` units
* `compress`: Details about the compression configuration for this connection
This event contains the following metadata:
* `telemetry_span_context`: A unique identifier for this span
* `connection_telemetry_span_context`: The span context of the Thousand Island `:connection`
span which contains this request
This span is ended by the following event:
* `[:bandit, :websocket, :stop]`
Represents the end of the span
This event contains the following measurements:
* `monotonic_time`: The time of this event, in `:native` units
* `duration`: The span duration, in `:native` units
* `recv_text_frame_count`: The number of text frames received
* `recv_text_frame_bytes`: The total number of bytes received in the payload of text frames
* `recv_binary_frame_count`: The number of binary frames received
* `recv_binary_frame_bytes`: The total number of bytes received in the payload of binary frames
* `recv_ping_frame_count`: The number of ping frames received
* `recv_ping_frame_bytes`: The total number of bytes received in the payload of ping frames
* `recv_pong_frame_count`: The number of pong frames received
* `recv_pong_frame_bytes`: The total number of bytes received in the payload of pong frames
* `recv_connection_close_frame_count`: The number of connection close frames received
* `recv_connection_close_frame_bytes`: The total number of bytes received in the payload of connection close frames
* `recv_continuation_frame_count`: The number of continuation frames received
* `recv_continuation_frame_bytes`: The total number of bytes received in the payload of continuation frames
* `send_text_frame_count`: The number of text frames sent
* `send_text_frame_bytes`: The total number of bytes sent in the payload of text frames
* `send_binary_frame_count`: The number of binary frames sent
* `send_binary_frame_bytes`: The total number of bytes sent in the payload of binary frames
* `send_ping_frame_count`: The number of ping frames sent
* `send_ping_frame_bytes`: The total number of bytes sent in the payload of ping frames
* `send_pong_frame_count`: The number of pong frames sent
* `send_pong_frame_bytes`: The total number of bytes sent in the payload of pong frames
* `send_connection_close_frame_count`: The number of connection close frames sent
* `send_connection_close_frame_bytes`: The total number of bytes sent in the payload of connection close frames
* `send_continuation_frame_count`: The number of continuation frames sent
* `send_continuation_frame_bytes`: The total number of bytes sent in the payload of continuation frames
This event contains the following metadata:
* `telemetry_span_context`: A unique identifier for this span
* `origin_telemetry_span_context`: The span context of the Bandit `:request` span from which
this connection originated
* `connection_telemetry_span_context`: The span context of the Thousand Island `:connection`
span which contains this request
* `error`: The error that caused the span to end, if it ended in error
"""
defstruct span_name: nil, telemetry_span_context: nil, start_time: nil, start_metadata: nil
@typep span_name :: atom()
@opaque t :: %__MODULE__{
span_name: span_name(),
telemetry_span_context: reference(),
start_time: integer(),
start_metadata: :telemetry.event_metadata()
}
@app_name :bandit
@doc false
@spec start_span(span_name(), :telemetry.event_measurements(), :telemetry.event_metadata()) ::
t()
def start_span(span_name, measurements \\ %{}, metadata \\ %{}) do
measurements = Map.put_new_lazy(measurements, :monotonic_time, &monotonic_time/0)
telemetry_span_context = make_ref()
metadata = Map.put(metadata, :telemetry_span_context, telemetry_span_context)
event([span_name, :start], measurements, metadata)
%__MODULE__{
span_name: span_name,
telemetry_span_context: telemetry_span_context,
start_time: measurements[:monotonic_time],
start_metadata: metadata
}
end
@doc false
@spec stop_span(t(), :telemetry.event_measurements(), :telemetry.event_metadata()) :: :ok
def stop_span(span, measurements \\ %{}, metadata \\ %{}) do
measurements = Map.put_new_lazy(measurements, :monotonic_time, &monotonic_time/0)
measurements =
Map.put(measurements, :duration, measurements[:monotonic_time] - span.start_time)
metadata = Map.merge(span.start_metadata, metadata)
untimed_span_event(span, :stop, measurements, metadata)
end
@spec span_exception(t(), Exception.kind(), Exception.t(), Exception.stacktrace()) :: :ok
def span_exception(span, kind, exception, stacktrace) do
metadata =
Map.merge(span.start_metadata, %{
kind: kind,
exception: exception,
stacktrace: stacktrace
})
span_event(span, :exception, %{}, metadata)
end
@doc false
@spec span_event(t(), span_name(), :telemetry.event_measurements(), :telemetry.event_metadata()) ::
:ok
def span_event(span, name, measurements \\ %{}, metadata \\ %{}) do
measurements = Map.put_new_lazy(measurements, :monotonic_time, &monotonic_time/0)
untimed_span_event(span, name, measurements, metadata)
end
@doc false
@spec untimed_span_event(
t(),
span_name(),
:telemetry.event_measurements(),
:telemetry.event_metadata()
) :: :ok
def untimed_span_event(span, name, measurements \\ %{}, metadata \\ %{}) do
metadata = Map.put(metadata, :telemetry_span_context, span.telemetry_span_context)
event([span.span_name, name], measurements, metadata)
end
@spec monotonic_time :: integer()
defdelegate monotonic_time, to: System
@spec event(
:telemetry.event_name(),
:telemetry.event_measurements(),
:telemetry.event_metadata()
) :: :ok
defp event(suffix, measurements, metadata) do
:telemetry.execute([@app_name | suffix], measurements, metadata)
end
@doc false
@spec telemetry_span_context(t()) :: reference()
def telemetry_span_context(span) do
span.telemetry_span_context
end
end