Method executeBackendRequests

tools/querytee/proxy_endpoint.go:74–141

(r *http.Request, resCh chan *backendResponse)

}

func (p *ProxyEndpoint) executeBackendRequests(r *http.Request, resCh chan *backendResponse) {
	responses := make([]*backendResponse, 0, len(p.backends))

	var (
		wg  = sync.WaitGroup{}
		mtx = sync.Mutex{}
	)
	wg.Add(len(p.backends))

	for _, b := range p.backends {

		go func() {
			defer wg.Done()

			start := time.Now()
			status, body, err := b.ForwardRequest(r)
			elapsed := time.Since(start)

			res := &backendResponse{
				backend: b,
				status:  status,
				body:    body,
				err:     err,
			}

			// Log with a level based on the backend response.
			lvl := level.Debug
			if !res.succeeded() {
				lvl = level.Warn
			}

			lvl(p.logger).Log("msg", "Backend response", "path", r.URL.Path, "query", r.URL.RawQuery, "backend", b.name, "status", status, "elapsed", elapsed)
			p.metrics.requestDuration.WithLabelValues(res.backend.name, r.Method, p.routeName, strconv.Itoa(res.statusCode())).Observe(elapsed.Seconds())

			// Keep track of the response if required.
			if p.comparator != nil {
				mtx.Lock()
				responses = append(responses, res)
				mtx.Unlock()
			}

			resCh <- res
		}()
	}

	// Wait until all backend requests completed.
	wg.Wait()
	close(resCh)

	// Compare responses.
	if p.comparator != nil {
		expectedResponse := responses[0]
		actualResponse := responses[1]
		if responses[1].backend.preferred {
			expectedResponse, actualResponse = actualResponse, expectedResponse
		}

		result := comparisonSuccess