Module: Rage::Telemetry::Capacity

Defined in:
lib/rage/telemetry/capacity.rb

Overview

The Rage::Telemetry::Capacity module exposes framework-owned runtime state - metrics describing the server's current load and resource utilization that cannot be derived from existing spans.

Unlike spans, capacity metrics aren't tied to a specific operation or event, they reflect the server state at the moment they are read, and are meant to be sampled periodically rather than triggered by handlers.

Combine with every to report a metric on a fixed interval:

Rage::Telemetry.every(1000) do
  MyMetrics.gauge("server.queued_connections", Rage::Telemetry::Capacity.queued_connections)
end

See Also:

Class Method Summary collapse

Class Method Details

.queued_connections ⇒ Integer

Returns the number of established connections currently waiting in the kernel accept queue for the server listening sockets. This is the count of clients that have already completed the TCP handshake but haven't yet been picked up by the application via accept().

A value that stays bigger than 0 is a sign the server isn't accepting connections fast enough to keep up with incoming traffic.

Returns:

  • (Integer) —

    the accept-queue depth

Raises:

  • (NotImplementedError) —

    on non-Linux systems



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# File 'lib/rage/telemetry/capacity.rb', line 34

def queued_connections
  accept_queue_depth = Iodine::Perf.queued_connections
  raise NotImplementedError if accept_queue_depth.nil?

  accept_queue_depth
end