Class: MonoVM::Whois::Transport::Middleware::Instrumentation

Inherits:
Middleware::Base
  • Object
show all
Defined in:
lib/monovm/whois/transport/middleware/instrumentation.rb

Overview

Reports every exchange to a subscriber.

A registrar running this at volume needs to know which registries are slow and which are refusing, and that is the host application's concern, not this library's. So nothing is logged here — an event is handed to whatever was injected, and the caller decides whether it becomes a log line, a StatsD counter or nothing at all.

Instance Method Summary collapse

Constructor Details

#initialize(app, subscriber:) ⇒ Instrumentation

Returns a new instance of Instrumentation.

Parameters:

  • subscriber (#call) —

    receives one Hash per exchange



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# File 'lib/monovm/whois/transport/middleware/instrumentation.rb', line 18

def initialize(app, subscriber:)
  @subscriber = subscriber
  super(app)
end

Instance Method Details

#fetch(query:, endpoint:) ⇒ Object 



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# File 'lib/monovm/whois/transport/middleware/instrumentation.rb', line 23

def fetch(query:, endpoint:)
  started = Process.clock_gettime(Process::CLOCK_MONOTONIC)

  begin
    response = app.fetch(query: query, endpoint: endpoint)
  rescue StandardError => e
    publish(
      query: query,
      endpoint: endpoint,
      outcome: :error,
      error: e.class.name,
      message: e.message,
      elapsed: Process.clock_gettime(Process::CLOCK_MONOTONIC) - started
    )
    raise
  end

  publish(
    query: query,
    endpoint: endpoint,
    outcome: :ok,
    status: response.status,
    bytes: response.body.length,
    elapsed: Process.clock_gettime(Process::CLOCK_MONOTONIC) - started
  )
  response
end