Enhance split cmd and fix bug

1. Add split-range cmd to support StartKeyspaceID and EndKeyspaceID parameters.
2. Fix "split 0 2 2 2" generate duplicate keyspaces in the keyspace list of the group"

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

pkg/keyspace/tso_keyspace_group.go

@@ -615,7 +615,15 @@ func buildSplitKeyspaces(
 				oldSplit = append(oldSplit, keyspace)
 			}
 		}
-		return oldSplit, new, nil
+		// Dedup new keyspaces if it's necessary.
+		if newNum == len(newKeyspaceMap) {
+			return oldSplit, new, nil
+		}
+		newSplit := make([]uint32, 0, len(newKeyspaceMap))
+		for keyspace := range newKeyspaceMap {
+			newSplit = append(newSplit, keyspace)
+		}
+		return oldSplit, newSplit, nil
 	}
 	// Split according to the start and end keyspace ID.
 	if startKeyspaceID == 0 && endKeyspaceID == 0 {

tools/pd-ctl/pdctl/command/keyspace_group_command.go

@@ -33,6 +33,7 @@ func NewKeyspaceGroupCommand() *cobra.Command {
 		Run:   showKeyspaceGroupCommandFunc,
 	}
 	cmd.AddCommand(newSplitKeyspaceGroupCommand())
+	cmd.AddCommand(newSplitRangeKeyspaceGroupCommand())
 	cmd.AddCommand(newFinishSplitKeyspaceGroupCommand())
 	cmd.AddCommand(newMergeKeyspaceGroupCommand())
 	cmd.AddCommand(newFinishMergeKeyspaceGroupCommand())
@@ -50,6 +51,15 @@ func newSplitKeyspaceGroupCommand() *cobra.Command {
 	return r
 }
 
+func newSplitRangeKeyspaceGroupCommand() *cobra.Command {
+	r := &cobra.Command{
+		Use:   "split-range <keyspace_group_id> <new_keyspace_group_id> <start_keyspace_id> <end_keyspace_id>",
+		Short: "split the keyspace group with the given ID and transfer the keyspaces in the given range (both ends inclusive) into the newly split one",
+		Run:   splitRangeKeyspaceGroupCommandFunc,
+	}
+	return r
+}
+
 func newFinishSplitKeyspaceGroupCommand() *cobra.Command {
 	r := &cobra.Command{
 		Use:    "finish-split <keyspace_group_id>",
@@ -140,6 +150,38 @@ func splitKeyspaceGroupCommandFunc(cmd *cobra.Command, args []string) {
 	})
 }
 
+func splitRangeKeyspaceGroupCommandFunc(cmd *cobra.Command, args []string) {
+	if len(args) < 4 {
+		cmd.Usage()
+		return
+	}
+	_, err := strconv.ParseUint(args[0], 10, 32)
+	if err != nil {
+		cmd.Printf("Failed to parse the old keyspace group ID: %s\n", err)
+		return
+	}
+	newID, err := strconv.ParseUint(args[1], 10, 32)
+	if err != nil {
+		cmd.Printf("Failed to parse the new keyspace group ID: %s\n", err)
+		return
+	}
+	startKeyspaceID, err := strconv.ParseUint(args[2], 10, 32)
+	if err != nil {
+		cmd.Printf("Failed to parse the start keyspace ID: %s\n", err)
+		return
+	}
+	endKeyspaceID, err := strconv.ParseUint(args[3], 10, 32)
+	if err != nil {
+		cmd.Printf("Failed to parse the end keyspace ID: %s\n", err)
+		return
+	}
+	postJSON(cmd, fmt.Sprintf("%s/%s/split", keyspaceGroupsPrefix, args[0]), map[string]interface{}{
+		"new-id":            uint32(newID),
+		"start-keyspace-id": uint32(startKeyspaceID),
+		"end-keyspace-id":   uint32(endKeyspaceID),
+	})
+}
+
 func finishSplitKeyspaceGroupCommandFunc(cmd *cobra.Command, args []string) {
 	if len(args) < 1 {
 		cmd.Usage()