determine and verify OceanBase connection

Author: whhe

go/base/utils.go

@@ -6,6 +6,7 @@
 package base
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"regexp"
@@ -62,6 +63,10 @@ func StringContainsAll(s string, substrings ...string) bool {
 }
 
 func ValidateConnection(db *gosql.DB, connectionConfig *mysql.ConnectionConfig, migrationContext *MigrationContext, name string) (string, error) {
+	if err := validateOceanBaseConnection(db, migrationContext); err != nil {
+		return "", err
+	}
+
 	versionQuery := `select @@global.version`
 
 	var version string
@@ -102,3 +107,26 @@ func ValidateConnection(db *gosql.DB, connectionConfig *mysql.ConnectionConfig,
 		return "", fmt.Errorf("Unexpected database port reported: %+v / extra_port: %+v", port, extraPort)
 	}
 }
+
+func validateOceanBaseConnection(db *gosql.DB, migrationContext *MigrationContext) error {
+	versionCommentQuery := `select @@global.version_comment`
+	var versionComment string
+	if err := db.QueryRow(versionCommentQuery).Scan(&versionComment); err != nil {
+		return nil
+	}
+	if !strings.Contains(versionComment, "OceanBase") {
+		return nil
+	}
+
+	migrationContext.OceanBase = true
+
+	enableLockPriorityQuery := `select value from oceanbase.GV$OB_PARAMETERS where name='enable_lock_priority'`
+	var enableLockPriority bool
+	if err := db.QueryRow(enableLockPriorityQuery).Scan(&enableLockPriority); err != nil {
+		return err
+	}
+	if !enableLockPriority {
+		return errors.New("system parameter 'enable_lock_priority' should be true to support cut-over")
+	}
+	return nil
+}

go/cmd/gh-ost/main.go

@@ -86,7 +86,6 @@ func main() {
 	flag.BoolVar(&migrationContext.AliyunRDS, "aliyun-rds", false, "set to 'true' when you execute on Aliyun RDS.")
 	flag.BoolVar(&migrationContext.GoogleCloudPlatform, "gcp", false, "set to 'true' when you execute on a 1st generation Google Cloud Platform (GCP).")
 	flag.BoolVar(&migrationContext.AzureMySQL, "azure", false, "set to 'true' when you execute on Azure Database on MySQL.")
-	flag.BoolVar(&migrationContext.OceanBase, "oceanbase", false, "set to 'true' when you execute on OceanBase")
 
 	executeFlag := flag.Bool("execute", false, "actually execute the alter & migrate the table. Default is noop: do some tests and exit")
 	flag.BoolVar(&migrationContext.TestOnReplica, "test-on-replica", false, "Have the migration run on a replica, not on the master. At the end of migration replication is stopped, and tables are swapped and immediately swap-revert. Replication remains stopped and you can compare the two tables for building trust")