Always try attempt on first try in order to get relevant context cancellation error. Cleanup err handling in balanced selector. Fallback to response status code if cgr error isn't defined.

Author: dtrejod

conjure-go-client/httpclient/client.go

@@ -107,7 +107,10 @@ func (c *clientImpl) Do(ctx context.Context, params ...RequestParam) (*http.Resp
 		}
 		svc1log.FromContext(ctx).Debug("Retrying request", svc1log.Stacktrace(err))
 	}
-	return resp, err
+	if err != nil {
+		return nil, err
+	}
+	return resp, nil
 }
 
 func (c *clientImpl) doOnce(

conjure-go-client/httpclient/internal/balanced_selector.go

@@ -103,14 +103,15 @@ func (s *balancedSelector) RoundTrip(req *http.Request, next http.RoundTripper)
 	defer s.updateInflight(baseURI, -1)
 
 	resp, err := next.RoundTrip(req)
-	if resp == nil || err != nil {
-		s.updateRecentFailures(baseURI, failureWeight)
-		return nil, err
+	errCode, ok := StatusCodeFromError(err)
+	// fall back to the status code from the response
+	if !ok && resp != nil {
+		errCode = resp.StatusCode
 	}
-	statusCode := resp.StatusCode
-	if isGlobalQosStatus(statusCode) || isServerErrorRange(statusCode) {
+
+	if isGlobalQosStatus(errCode) || isServerErrorRange(errCode) {
 		s.updateRecentFailures(baseURI, failureWeight)
-	} else if isClientError(statusCode) {
+	} else if isClientError(errCode) {
 		s.updateRecentFailures(baseURI, failureWeight/100)
 	}
 	return resp, err

conjure-go-client/httpclient/internal/request_retrier.go

@@ -84,6 +84,14 @@ func (r *RequestRetrier) Next(resp *http.Response, err error) (bool, *url.URL) {
 		return false, nil
 	}
 
+	// should always try first request
+	if r.attemptCount == 0 {
+		// Trigger the first retry so later calls have backoff but ignore the returned value to ensure that the
+		// client can instrument the request even if the context is done.
+		r.retrier.Next()
+		return true, nil
+	}
+
 	// retry with backoff
 	return r.retrier.Next(), nil
 }

conjure-go-client/httpclient/internal/stateful_uri_pool.go

@@ -78,16 +78,18 @@ func (s *statefulURIPool) URIs() []string {
 // RoundTrip implements URIPool
 func (s *statefulURIPool) RoundTrip(req *http.Request, next http.RoundTripper) (*http.Response, error) {
 	resp, err := next.RoundTrip(req)
-	errCode, _ := StatusCodeFromError(err)
+	errCode, ok := StatusCodeFromError(err)
+	// fall back to the status code from the response
+	if !ok && resp != nil {
+		errCode = resp.StatusCode
+	}
 
 	if isThrottle, ressurectAfter := isThrottleResponse(resp, errCode); isThrottle {
 		s.markBackoffURI(req, ressurectAfter)
-	}
-	if isUnavailableResponse(resp, errCode) {
+	} else if isUnavailableResponse(resp, errCode) {
 		// 503: go to next node
 		s.markBackoffURI(req, defaultResurrectDuration)
-	}
-	if resp == nil {
+	} else if resp == nil {
 		// if we get a nil response, we can assume there is a problem with host and can move on to the next.
 		s.markBackoffURI(req, defaultResurrectDuration)
 	}