From 0f242e7861c8ce226fea0bca5d09a78c98fa4830 Mon Sep 17 00:00:00 2001
From: Cyril Tovena <cyril.tovena@gmail.com>
Date: Fri, 22 Nov 2024 16:24:09 +0100
Subject: [PATCH] chore(refactor): Avoid goroutine leak in case of fetching
 errors (#15018)

---
 pkg/storage/async_store.go | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/pkg/storage/async_store.go b/pkg/storage/async_store.go
index 5d9752f8813ea..212b7a3776206 100644
--- a/pkg/storage/async_store.go
+++ b/pkg/storage/async_store.go
@@ -7,6 +7,7 @@ import (
 
 	"github.com/c2h5oh/datasize"
 	"github.com/opentracing/opentracing-go"
+	"golang.org/x/sync/errgroup"
 
 	"github.com/grafana/loki/v3/pkg/logproto"
 	"github.com/grafana/loki/v3/pkg/storage/stores"
@@ -72,23 +73,23 @@ func (a *AsyncStore) GetChunks(ctx context.Context,
 	predicate chunk.Predicate,
 	storeChunksOverride *logproto.ChunkRefGroup,
 ) ([][]chunk.Chunk, []*fetcher.Fetcher, error) {
-	errs := make(chan error)
 
 	var storeChunks [][]chunk.Chunk
+	g, ctx := errgroup.WithContext(ctx)
+
 	var fetchers []*fetcher.Fetcher
-	go func() {
+	g.Go(func() error {
 		var err error
 		storeChunks, fetchers, err = a.Store.GetChunks(ctx, userID, from, through, predicate, storeChunksOverride)
-		errs <- err
-	}()
+		return err
+	})
 
 	var ingesterChunks []string
 
-	go func() {
+	g.Go(func() error {
 		if !a.shouldQueryIngesters(through, model.Now()) {
 			level.Debug(util_log.Logger).Log("msg", "skipping querying ingesters for chunk ids", "query-from", from, "query-through", through)
-			errs <- nil
-			return
+			return nil
 		}
 
 		var err error
@@ -100,14 +101,11 @@ func (a *AsyncStore) GetChunks(ctx context.Context,
 			}
 			level.Debug(util_log.Logger).Log("msg", "got chunk ids from ingester", "count", len(ingesterChunks))
 		}
-		errs <- err
-	}()
+		return err
+	})
 
-	for i := 0; i < 2; i++ {
-		err := <-errs
-		if err != nil {
-			return nil, nil, err
-		}
+	if err := g.Wait(); err != nil {
+		return nil, nil, err
 	}
 
 	if len(ingesterChunks) == 0 {