server/tso: fix the panic issue when getTS in the follower (tikv#1930)

Signed-off-by: nolouch <nolouch@gmail.com>

server/server_test.go

@@ -49,45 +49,6 @@ func mustWaitLeader(c *C, svrs []*Server) *Server {
 	return leader
 }
 
-var _ = Suite(&testLeaderServerSuite{})
-
-type testLeaderServerSuite struct {
-	svrs       map[string]*Server
-	leaderPath string
-}
-
-func (s *testLeaderServerSuite) SetUpSuite(c *C) {
-	s.svrs = make(map[string]*Server)
-
-	cfgs := NewTestMultiConfig(c, 3)
-
-	ch := make(chan *Server, 3)
-	for i := 0; i < 3; i++ {
-		cfg := cfgs[i]
-
-		go func() {
-			svr, err := CreateServer(cfg, nil)
-			c.Assert(err, IsNil)
-			err = svr.Run(context.TODO())
-			c.Assert(err, IsNil)
-			ch <- svr
-		}()
-	}
-
-	for i := 0; i < 3; i++ {
-		svr := <-ch
-		s.svrs[svr.GetAddr()] = svr
-		s.leaderPath = svr.getLeaderPath()
-	}
-}
-
-func (s *testLeaderServerSuite) TearDownSuite(c *C) {
-	for _, svr := range s.svrs {
-		svr.Close()
-		cleanServer(svr.cfg)
-	}
-}
-
 var _ = Suite(&testServerSuite{})
 
 type testServerSuite struct{}
@@ -100,6 +61,7 @@ func newTestServersWithCfgs(c *C, cfgs []*Config) ([]*Server, CleanupFunc) {
 		go func(cfg *Config) {
 			svr, err := CreateServer(cfg, nil)
 			c.Assert(err, IsNil)
+			c.Assert(svr, NotNil)
 			err = svr.Run(context.TODO())
 			c.Assert(err, IsNil)
 			ch <- svr

server/tso.go

@@ -214,7 +214,7 @@ func (s *Server) updateTimestamp() error {
 	return nil
 }
 
-const maxRetryCount = 100
+var maxRetryCount = 100
 
 func (s *Server) getRespTS(count uint32) (pdpb.Timestamp, error) {
 	var resp pdpb.Timestamp
@@ -225,7 +225,7 @@ func (s *Server) getRespTS(count uint32) (pdpb.Timestamp, error) {
 
 	for i := 0; i < maxRetryCount; i++ {
 		current := (*atomicObject)(atomic.LoadPointer(&s.ts))
-		if current.physical == zeroTime {
+		if current == nil || current.physical == zeroTime {
 			log.Error("we haven't synced timestamp ok, wait and retry", zap.Int("retry-count", i))
 			time.Sleep(200 * time.Millisecond)
 			continue

server/tso_test.go

@@ -15,6 +15,7 @@ package server
 
 import (
 	"context"
+	"strings"
 	"sync"
 	"time"
 
@@ -193,3 +194,68 @@ func mustGetLeader(c *C, client *clientv3.Client, leaderPath string) *pdpb.Membe
 	c.Fatal("get leader error")
 	return nil
 }
+
+var _ = Suite(&testFollowerTsoSuite{})
+
+type testFollowerTsoSuite struct {
+	ctx    context.Context
+	cancel context.CancelFunc
+	svrs   []*Server
+}
+
+func (s *testFollowerTsoSuite) SetUpSuite(c *C) {
+	s.svrs = make([]*Server, 0, 2)
+
+	cfgs := NewTestMultiConfig(c, 2)
+	ch := make(chan *Server, 2)
+	for i := 0; i < 2; i++ {
+		cfg := cfgs[i]
+		go func() {
+			svr, err := CreateServer(cfg, nil)
+			c.Assert(err, IsNil)
+			c.Assert(svr, NotNil)
+			err = svr.Run(context.TODO())
+			c.Assert(err, IsNil)
+			ch <- svr
+		}()
+	}
+
+	for i := 0; i < 2; i++ {
+		svr := <-ch
+		s.svrs = append(s.svrs, svr)
+	}
+	mustWaitLeader(c, s.svrs)
+}
+
+func (s *testFollowerTsoSuite) TearDownSuite(c *C) {
+	for _, svr := range s.svrs {
+		svr.Close()
+		cleanServer(svr.cfg)
+	}
+}
+
+func (s *testFollowerTsoSuite) TestRequest(c *C) {
+	var err error
+
+	var followerServer *Server
+	for _, s := range s.svrs {
+		if !s.IsLeader() {
+			followerServer = s
+		}
+	}
+	c.Assert(followerServer, NotNil)
+	grpcPDClient := mustNewGrpcClient(c, followerServer.GetAddr())
+	clusterID := followerServer.ClusterID()
+
+	req := &pdpb.TsoRequest{Header: newRequestHeader(clusterID), Count: 1}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	tsoClient, err := grpcPDClient.Tso(ctx)
+	c.Assert(err, IsNil)
+	defer tsoClient.CloseSend()
+	err = tsoClient.Send(req)
+	c.Assert(err, IsNil)
+	_, err = tsoClient.Recv()
+	c.Assert(err, NotNil)
+	c.Assert(strings.Contains(err.Error(), "not leader"), IsTrue)
+}