Module: Px::Service::Client::CircuitBreaker

Extended by:
ActiveSupport::Concern
Includes:
CircuitBreaker
Defined in:
lib/px/service/client/circuit_breaker.rb

Instance Method Summary collapse

Instance Method Details

#_make_request_with_breaker(method, uri, query: nil, headers: nil, body: nil, timeout: nil, stats_tags: []) ⇒ Object

Make the request, respecting the circuit breaker, if configured



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# File 'lib/px/service/client/circuit_breaker.rb', line 26

def _make_request_with_breaker(method, uri, query: nil, headers: nil, body: nil, timeout: nil, stats_tags: [])
  state = self.class.circuit_state
  handler = self.class.circuit_handler

  if handler.is_tripped(state)
    handler.logger.debug("handle: breaker is tripped, refusing to execute: #{state}") if handler.logger
    begin
      handler.on_circuit_open(state)
    rescue StandardError => ex
      # Wrap and reroute other exceptions, includes CircuitBreaker::CircuitBrokenException
      error = Px::Service::ServiceError.new(ex.message, 503)
      return CircuitBreakerRetriableResponseFuture.new(error)
    end
  end

  config.statsd_client.increment("breakers.ready.count", tags: stats_tags) if circuit_state.half_open?

  retry_request = _make_request_without_breaker(
    method,
    uri,
    query: query,
    headers: headers,
    body: body,
    timeout: handler.invocation_timeout,
    stats_tags: stats_tags)

  retry_request.request.on_complete do |response|
    # Wait for request to exhaust retries
    if retry_request.completed?
      if response.response_code >= 500 || response.response_code == 0
        config.statsd_client.increment("breakers.fail.count", tags: stats_tags)
        config.statsd_client.increment("breakers.tripped.count", tags: stats_tags) if circuit_state.closed?

        # as this code may be executed after context switch, we want to
        # check the state again
        handler.on_failure(state) unless handler.is_tripped(state)
      else
        config.statsd_client.increment("breakers.reset.count", tags: stats_tags) unless circuit_state.closed?
        handler.on_success(state)
      end
    end
  end

  retry_request
end