return error when failing to submit checkpoint request

Signed-off-by: Benjamin Wang <wachao@vmware.com>

server/etcdserver/server.go

@@ -396,8 +396,9 @@ func NewServer(cfg config.ServerConfig) (srv *EtcdServer, err error) {
 
 	if srv.Cfg.EnableLeaseCheckpoint {
 		// setting checkpointer enables lease checkpoint feature.
-		srv.lessor.SetCheckpointer(func(ctx context.Context, cp *pb.LeaseCheckpointRequest) {
-			srv.raftRequestOnce(ctx, pb.InternalRaftRequest{LeaseCheckpoint: cp})
+		srv.lessor.SetCheckpointer(func(ctx context.Context, cp *pb.LeaseCheckpointRequest) error {
+			_, lcerr := srv.raftRequestOnce(ctx, pb.InternalRaftRequest{LeaseCheckpoint: cp})
+			return lcerr
 		})
 	}
 

server/lease/lessor.go

@@ -75,7 +75,7 @@ type RangeDeleter func() TxnDelete
 
 // Checkpointer permits checkpointing of lease remaining TTLs to the consensus log. Defined here to
 // avoid circular dependency with mvcc.
-type Checkpointer func(ctx context.Context, lc *pb.LeaseCheckpointRequest)
+type Checkpointer func(ctx context.Context, lc *pb.LeaseCheckpointRequest) error
 
 type LeaseID int64
 
@@ -424,7 +424,9 @@ func (le *lessor) Renew(id LeaseID) (int64, error) {
 	// By applying a RAFT entry only when the remainingTTL is already set, we limit the number
 	// of RAFT entries written per lease to a max of 2 per checkpoint interval.
 	if clearRemainingTTL {
-		le.cp(context.Background(), &pb.LeaseCheckpointRequest{Checkpoints: []*pb.LeaseCheckpoint{{ID: int64(l.ID), Remaining_TTL: 0}}})
+		if err := le.cp(context.Background(), &pb.LeaseCheckpointRequest{Checkpoints: []*pb.LeaseCheckpoint{{ID: int64(l.ID), Remaining_TTL: 0}}}); err != nil {
+			return -1, err
+		}
 	}
 
 	le.mu.Lock()

server/lease/lessor_test.go

@@ -269,10 +269,11 @@ func TestLessorRenewWithCheckpointer(t *testing.T) {
 	defer os.RemoveAll(dir)
 
 	le := newLessor(lg, be, clusterLatest(), LessorConfig{MinLeaseTTL: minLeaseTTL})
-	fakerCheckerpointer := func(ctx context.Context, cp *pb.LeaseCheckpointRequest) {
+	fakerCheckerpointer := func(ctx context.Context, cp *pb.LeaseCheckpointRequest) error {
 		for _, cp := range cp.GetCheckpoints() {
 			le.Checkpoint(LeaseID(cp.GetID()), cp.GetRemaining_TTL())
 		}
+		return nil
 	}
 	defer le.Stop()
 	// Set checkpointer
@@ -556,7 +557,7 @@ func TestLessorCheckpointScheduling(t *testing.T) {
 	defer le.Stop()
 	le.minLeaseTTL = 1
 	checkpointedC := make(chan struct{})
-	le.SetCheckpointer(func(ctx context.Context, lc *pb.LeaseCheckpointRequest) {
+	le.SetCheckpointer(func(ctx context.Context, lc *pb.LeaseCheckpointRequest) error {
 		close(checkpointedC)
 		if len(lc.Checkpoints) != 1 {
 			t.Errorf("expected 1 checkpoint but got %d", len(lc.Checkpoints))
@@ -565,6 +566,7 @@ func TestLessorCheckpointScheduling(t *testing.T) {
 		if c.Remaining_TTL != 1 {
 			t.Errorf("expected checkpoint to be called with Remaining_TTL=%d but got %d", 1, c.Remaining_TTL)
 		}
+		return nil
 	})
 	_, err := le.Grant(1, 2)
 	if err != nil {