Class: Wurk::Telemetry::ClientMiddleware

Inherits:
Object
  • Object
show all
Includes:
ServerMiddleware
Defined in:
lib/wurk/telemetry/client_middleware.rb

Overview

Producer half of the pair: a <queue> publish span around the rest of the enqueue, with that span's W3C trace context written onto the job hash so the worker that eventually runs the job can tie its own span back to whoever pushed it. Injection happens once per payload, which means every push_bulk item gets its own context — the chain runs per item there (Client#build_bulk_payloads), not once for the slice.

Registered only by install!, i.e. only once the host opted in and opentelemetry-api is loaded. An app that did neither has no entry in the chain at all — no span, and not one extra byte on the wire.

Tail position (add) is deliberate on both counts: a middleware that halts the push — a uniqueness gem dropping a duplicate — runs outside this one, so no publish span is opened for a job that was never published; and nothing downstream of the injection can strip the key back off.

Instance Method Summary collapse

Instance Method Details

#call(_worker, job, queue, _redis_pool) ⇒ Object 



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# File 'lib/wurk/telemetry/client_middleware.rb', line 25

def call(_worker, job, queue, _redis_pool)
  Telemetry.tracer.in_span("#{queue} publish", attributes: attributes(job, queue), kind: :producer) do
    # Inside the span so the context written is the producer span's own,
    # which is what the consumer end links back to.
    #
    # The propagator writes `traceparent`, plus `tracestate` only when the
    # trace actually carries vendor state — top-level String values, so
    # this adds nothing to the args tree `verify_json` walks one frame in
    # (bulk verifies inside this very block; see
    # Client#invoke_chain_verified). The single-walk-per-push property
    # holds unchanged: this middleware never verifies.
    ::OpenTelemetry.propagation.inject(job)
    yield
  end
end