Change to expose header at Distributor side

Signed-off-by: SungJin1212 <tjdwls1201@gmail.com>

Author: SungJin1212

integration/remote_write_v2_test.go

@@ -26,7 +26,7 @@ import (
 
 func TestIngesterRollingUpdate(t *testing.T) {
 	// Test ingester rolling update situation: when -distributor.remote-write2-enabled is true, and ingester uses the v1.19.0 image.
-	// Expected: remote write 2.0 push success, but response header values are set to "0".
+	// Expected: remote write 2.0 push success
 	const blockRangePeriod = 5 * time.Second
 	ingesterImage := "quay.io/cortexproject/cortex:v1.19.0"
 

pkg/distributor/distributor.go

@@ -1199,14 +1199,13 @@ func (d *Distributor) send(ctx context.Context, ingester ring.InstanceDesc, time
 	d.inflightClientRequests.Inc()
 	defer d.inflightClientRequests.Dec()
 
-	var resp *cortexpb.WriteResponse
 	if d.cfg.UseStreamPush {
 		req := &cortexpb.WriteRequest{
 			Timeseries: timeseries,
 			Metadata:   metadata,
 			Source:     source,
 		}
-		resp, err = c.PushStreamConnection(ctx, req)
+		_, err = c.PushStreamConnection(ctx, req)
 	} else {
 		req := cortexpb.PreallocWriteRequestFromPool()
 		req.Timeseries = timeseries

pkg/distributor/write_stats.go

@@ -1579,13 +1579,7 @@ func (i *Ingester) Push(ctx context.Context, req *cortexpb.WriteRequest) (*corte
 		return &cortexpb.WriteResponse{}, httpgrpc.Errorf(code, "%s", wrapWithUser(firstPartialErr, userID).Error())
 	}
 
-	writeResponse := &cortexpb.WriteResponse{
-		Samples:    int64(succeededSamplesCount),
-		Histograms: int64(succeededHistogramsCount),
-		Exemplars:  int64(succeededExemplarsCount),
-	}
-
-	return writeResponse, nil
+	return &cortexpb.WriteResponse{}, nil
 }
 
 func (i *Ingester) PushStream(srv client.Ingester_PushStreamServer) error {