From 8039222846a28d2a313ac9479e4e58d9e922f6c1 Mon Sep 17 00:00:00 2001
From: Kemal Akkoyun <kakkoyun@gmail.com>
Date: Thu, 17 Dec 2020 11:20:54 +0300
Subject: [PATCH] Address review issues

Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
---
 pkg/receive/handler.go | 50 ++++++++++++++++++++++--------------------
 1 file changed, 26 insertions(+), 24 deletions(-)

diff --git a/pkg/receive/handler.go b/pkg/receive/handler.go
index 6c229428609..589a9f32a64 100644
--- a/pkg/receive/handler.go
+++ b/pkg/receive/handler.go
@@ -315,7 +315,7 @@ func (h *Handler) receiveHTTP(w http.ResponseWriter, r *http.Request) {
 		level.Debug(h.logger).Log("msg", "failed to handle request", "err", err)
 	}
 
-	switch writeErrorCause(err) {
+	switch determineWriteErrorCause(err, 1) {
 	case nil:
 		return
 	case errNotReady:
@@ -453,7 +453,7 @@ func (h *Handler) fanoutForward(pctx context.Context, tenant string, replicas ma
 					// When a MultiError is added to another MultiError, the error slices are concatenated, not nested.
 					// To avoid breaking the counting logic, we need to flatten the error.
 					level.Debug(h.logger).Log("msg", "local tsdb write failed", "err", err.Error())
-					ec <- errors.Wrapf(writeErrorCause(err), "store locally for endpoint %v", endpoint)
+					ec <- errors.Wrapf(determineWriteErrorCause(err, 1), "store locally for endpoint %v", endpoint)
 					return
 				}
 				ec <- nil
@@ -619,7 +619,7 @@ func (h *Handler) RemoteWrite(ctx context.Context, r *storepb.WriteRequest) (*st
 	if err != nil {
 		level.Debug(h.logger).Log("msg", "failed to handle request", "err", err)
 	}
-	switch writeErrorCause(err) {
+	switch determineWriteErrorCause(err, 1) {
 	case nil:
 		return &storepb.WriteResponse{}, nil
 	case errNotReady:
@@ -684,39 +684,41 @@ func determineWriteErrorCause(err error, threshold int) error {
 	if err == nil {
 		return nil
 	}
+
 	unwrappedErr := errors.Cause(err)
 	errs, ok := unwrappedErr.(errutil.MultiError)
 	if !ok {
 		errs = []error{unwrappedErr}
 	}
-	if threshold > 0 {
-		expErrs := expectedErrors{
-			{err: errConflict, cause: isConflict},
-			{err: errNotReady, cause: isNotReady},
-			{err: errUnavailable, cause: isUnavailable},
-		}
-		for _, exp := range expErrs {
-			exp.count = 0
-			for _, err := range errs {
-				if exp.cause(errors.Cause(err)) {
-					exp.count++
-				}
+	if len(errs) == 0 {
+		return nil
+	}
+
+	if threshold == 0 {
+		return nil
+	}
+	expErrs := expectedErrors{
+		{err: errConflict, cause: isConflict},
+		{err: errNotReady, cause: isNotReady},
+		{err: errUnavailable, cause: isUnavailable},
+	}
+	for _, exp := range expErrs {
+		exp.count = 0
+		for _, err := range errs {
+			if exp.cause(errors.Cause(err)) {
+				exp.count++
 			}
 		}
-		sort.Sort(sort.Reverse(expErrs))
-		if exp := expErrs[0]; exp.count >= threshold {
-			return exp.err
-		}
 	}
-	if len(errs) == 0 {
-		return nil
+	// Determine which error occurred most.
+	sort.Sort(sort.Reverse(expErrs))
+	if exp := expErrs[0]; exp.count >= threshold {
+		return exp.err
 	}
+
 	return err
 }
 
-// writeErrorCause extracts the root cause of a write error.
-func writeErrorCause(err error) error { return determineWriteErrorCause(err, 1) }
-
 func newPeerGroup(dialOpts ...grpc.DialOption) *peerGroup {
 	return &peerGroup{
 		dialOpts: dialOpts,