Fix test issue in TestRandomResignLeader. (#6410)

close #6404

We need to make sure the selected keyspaces are from different keyspace groups, otherwise multiple goroutines below could try to resign the primary of the same keyspace group and cause race condition.

Signed-off-by: Bin Shi <binshi.bing@gmail.com>

tests/integrations/tso/client_test.go

@@ -53,6 +53,11 @@ type tsoClientTestSuite struct {
 	// The TSO service in microservice mode.
 	tsoCluster *mcs.TestTSOCluster
 
+	keyspaceGroups []struct {
+		keyspaceGroupID uint32
+		keyspaceIDs     []uint32
+	}
+
 	backendEndpoints string
 	keyspaceIDs      []uint32
 	clients          []pd.Client
@@ -99,7 +104,7 @@ func (suite *tsoClientTestSuite) SetupSuite() {
 		suite.tsoCluster, err = mcs.NewTestTSOCluster(suite.ctx, 3, suite.backendEndpoints)
 		re.NoError(err)
 
-		params := []struct {
+		suite.keyspaceGroups = []struct {
 			keyspaceGroupID uint32
 			keyspaceIDs     []uint32
 		}{
@@ -108,7 +113,7 @@ func (suite *tsoClientTestSuite) SetupSuite() {
 			{2, []uint32{2}},
 		}
 
-		for _, param := range params {
+		for _, param := range suite.keyspaceGroups {
 			if param.keyspaceGroupID == 0 {
 				// we have already created default keyspace group, so we can skip it.
 				// keyspace 10 isn't assigned to any keyspace group, so they will be
@@ -127,8 +132,8 @@ func (suite *tsoClientTestSuite) SetupSuite() {
 			})
 		}
 
-		for _, param := range params {
-			suite.keyspaceIDs = append(suite.keyspaceIDs, param.keyspaceIDs...)
+		for _, keyspaceGroup := range suite.keyspaceGroups {
+			suite.keyspaceIDs = append(suite.keyspaceIDs, keyspaceGroup.keyspaceIDs...)
 		}
 
 		suite.clients = mcs.WaitForMultiKeyspacesTSOAvailable(
@@ -242,10 +247,15 @@ func (suite *tsoClientTestSuite) TestRandomResignLeader() {
 		time.Sleep(time.Duration(n) * time.Second)
 		if !suite.legacy {
 			wg := sync.WaitGroup{}
-			// Select the default keyspace and a randomly picked keyspace to test
-			keyspaceIDs := []uint32{mcsutils.DefaultKeyspaceID}
-			selectIdx := uint32(r.Intn(len(suite.keyspaceIDs)-1) + 1)
-			keyspaceIDs = append(keyspaceIDs, suite.keyspaceIDs[selectIdx])
+			// Select the first keyspace from all keyspace groups. We need to make sure the selected
+			// keyspaces are from different keyspace groups, otherwise multiple goroutines below could
+			// try to resign the primary of the same keyspace group and cause race condition.
+			keyspaceIDs := make([]uint32, 0)
+			for _, keyspaceGroup := range suite.keyspaceGroups {
+				if len(keyspaceGroup.keyspaceIDs) > 0 {
+					keyspaceIDs = append(keyspaceIDs, keyspaceGroup.keyspaceIDs[0])
+				}
+			}
 			wg.Add(len(keyspaceIDs))
 			for _, keyspaceID := range keyspaceIDs {
 				go func(keyspaceID uint32) {