server: fix cannot send error in heartbeat stream

server/cluster_test.go

@@ -535,16 +535,13 @@ func (s *testClusterSuite) TestConcurrentHandleRegion(c *C) {
 		}
 		go func(isReciver bool) {
 			if isReciver {
-				resp, err := stream.Recv()
+				_, err := stream.Recv()
 				c.Assert(err, IsNil)
-				c.Assert(resp.Header.GetError(), IsNil)
-				fmt.Println("get resp:", resp)
 				wg.Done()
 			}
 			for {
-				resp, err := stream.Recv()
+				_, err := stream.Recv()
 				c.Assert(err, IsNil)
-				c.Assert(resp.Header.GetError(), IsNil)
 			}
 		}(i == 0)
 	}

server/grpc_service.go

@@ -371,21 +371,20 @@ func (s *Server) RegionHeartbeat(stream pdpb.PD_RegionHeartbeatServer) error {
 		}
 
 		region := core.RegionFromHeartbeat(request)
-		if region.GetID() == 0 {
-			msg := fmt.Sprintf("invalid request region, %v", request)
-			hbStreams.sendErr(pdpb.ErrorType_UNKNOWN, msg, storeAddress, storeLabel)
+		if region.GetLeader() == nil {
+			log.Error("invalid request, the leader is nil", zap.Reflect("reqeust", request))
 			continue
 		}
-		if region.GetLeader() == nil {
-			msg := fmt.Sprintf("invalid request leader, %v", request)
-			hbStreams.sendErr(pdpb.ErrorType_UNKNOWN, msg, storeAddress, storeLabel)
+		if region.GetID() == 0 {
+			msg := fmt.Sprintf("invalid request region, %v", request)
+			hbStreams.sendErr(pdpb.ErrorType_UNKNOWN, msg, request.GetLeader(), storeAddress, storeLabel)
 			continue
 		}
 
 		err = cluster.HandleRegionHeartbeat(region)
 		if err != nil {
 			msg := err.Error()
-			hbStreams.sendErr(pdpb.ErrorType_UNKNOWN, msg, storeAddress, storeLabel)
+			hbStreams.sendErr(pdpb.ErrorType_UNKNOWN, msg, request.GetLeader(), storeAddress, storeLabel)
 		}
 
 		regionHeartbeatCounter.WithLabelValues(storeAddress, storeLabel, "report", "ok").Inc()

server/heartbeat_stream_test.go

@@ -60,10 +60,19 @@ func (s *testHeartbeatStreamSuite) TestActivity(c *C) {
 	defer stream1.close()
 	defer stream2.close()
 	checkActiveStream := func() int {
+		// 1 means stream1 got a valid response
+		// 2 means stream2 got a valid response
+		// 3 means got an invalid response
 		select {
-		case <-stream1.respCh:
+		case resp := <-stream1.respCh:
+			if resp.GetHeader().GetError() != nil {
+				return 3
+			}
 			return 1
-		case <-stream2.respCh:
+		case resp := <-stream2.respCh:
+			if resp.GetHeader().GetError() != nil {
+				return 3
+			}
 			return 2
 		case <-time.After(time.Second):
 			return 0
@@ -74,12 +83,21 @@ func (s *testHeartbeatStreamSuite) TestActivity(c *C) {
 		Leader: s.region.Peers[0],
 		Region: s.region,
 	}
+	invalidRegion := &metapb.Region{Id: 0}
+	invalidReq := &pdpb.RegionHeartbeatRequest{
+		Header: newRequestHeader(s.svr.clusterID),
+		Leader: s.region.Peers[0],
+		Region: invalidRegion,
+	}
 	// Active stream is stream1.
 	c.Assert(stream1.stream.Send(req), IsNil)
 	c.Assert(checkActiveStream(), Equals, 1)
 	// Rebind to stream2.
 	c.Assert(stream2.stream.Send(req), IsNil)
 	c.Assert(checkActiveStream(), Equals, 2)
+	// SendErr to stream2.
+	c.Assert(stream2.stream.Send(invalidReq), IsNil)
+	c.Assert(checkActiveStream(), Equals, 3)
 	// Rebind to stream1 if no more heartbeats sent through stream2.
 	testutil.WaitUntil(c, func(c *C) bool {
 		c.Assert(stream1.stream.Send(req), IsNil)

server/heartbeat_streams.go

@@ -19,6 +19,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/pingcap/kvproto/pkg/metapb"
 	"github.com/pingcap/kvproto/pkg/pdpb"
 	log "github.com/pingcap/log"
 	"github.com/pingcap/pd/pkg/logutil"
@@ -164,7 +165,7 @@ func (s *heartbeatStreams) SendMsg(region *core.RegionInfo, msg *pdpb.RegionHear
 	}
 }
 
-func (s *heartbeatStreams) sendErr(errType pdpb.ErrorType, errMsg string, storeAddress string, storeLabel string) {
+func (s *heartbeatStreams) sendErr(errType pdpb.ErrorType, errMsg string, targetPeer *metapb.Peer, storeAddress, storeLabel string) {
 	regionHeartbeatCounter.WithLabelValues(storeAddress, storeLabel, "report", "err").Inc()
 
 	msg := &pdpb.RegionHeartbeatResponse{
@@ -175,6 +176,7 @@ func (s *heartbeatStreams) sendErr(errType pdpb.ErrorType, errMsg string, storeA
 				Message: errMsg,
 			},
 		},
+		TargetPeer: targetPeer,
 	}
 
 	select {