ddl: add owner_id field to tidb_mdl_info to avoid unexpected writes

br/pkg/restore/db_test.go

@@ -425,5 +425,5 @@ func TestGetExistedUserDBs(t *testing.T) {
 //
 // The above variables are in the file br/pkg/restore/systable_restore.go
 func TestMonitorTheSystemTableIncremental(t *testing.T) {
-	require.Equal(t, int64(197), session.CurrentBootstrapVersion)
+	require.Equal(t, int64(198), session.CurrentBootstrapVersion)
 }

pkg/ddl/ddl_worker.go

@@ -605,18 +605,19 @@ func (w *worker) registerMDLInfo(job *model.Job, ver int64) error {
 	if len(rows) == 0 {
 		return errors.Errorf("can't find ddl job %d", job.ID)
 	}
+	ownerID := w.ownerManager.ID()
 	ids := rows[0].GetString(0)
-	sql := fmt.Sprintf("replace into mysql.tidb_mdl_info (job_id, version, table_ids) values (%d, %d, '%s')", job.ID, ver, ids)
+	sql := fmt.Sprintf("replace into mysql.tidb_mdl_info (job_id, version, table_ids, owner_id) values (%d, %d, '%s', '%s')", job.ID, ver, ids, ownerID)
 	_, err = w.sess.Execute(context.Background(), sql, "register-mdl-info")
 	return err
 }
 
 // cleanMDLInfo cleans metadata lock info.
-func cleanMDLInfo(pool *sess.Pool, jobID int64, ec *clientv3.Client, cleanETCD bool) {
+func cleanMDLInfo(pool *sess.Pool, jobID int64, ec *clientv3.Client, ownerID string, cleanETCD bool) {
 	if !variable.EnableMDL.Load() {
 		return
 	}
-	sql := fmt.Sprintf("delete from mysql.tidb_mdl_info where job_id = %d", jobID)
+	sql := fmt.Sprintf("delete from mysql.tidb_mdl_info where job_id = %d and owner_id = '%s'", jobID, ownerID)
 	sctx, _ := pool.Get()
 	defer pool.Put(sctx)
 	se := sess.NewSession(sctx)

pkg/ddl/job_table.go

@@ -425,6 +425,7 @@ func (d *ddl) delivery2Worker(wk *worker, pool *workerPool, job *model.Job) {
 			asyncNotify(d.ddlJobCh)
 			metrics.DDLRunningJobCount.WithLabelValues(pool.tp().String()).Dec()
 		}()
+		ownerID := d.ownerManager.ID()
 		// check if this ddl job is synced to all servers.
 		if !job.NotStarted() && (!d.isSynced(job) || !d.maybeAlreadyRunOnce(job.ID)) {
 			if variable.EnableMDL.Load() {
@@ -442,7 +443,7 @@ func (d *ddl) delivery2Worker(wk *worker, pool *workerPool, job *model.Job) {
 						return
 					}
 					d.setAlreadyRunOnce(job.ID)
-					cleanMDLInfo(d.sessPool, job.ID, d.etcdCli, job.State == model.JobStateSynced)
+					cleanMDLInfo(d.sessPool, job.ID, d.etcdCli, ownerID, job.State == model.JobStateSynced)
 					// Don't have a worker now.
 					return
 				}
@@ -480,7 +481,7 @@ func (d *ddl) delivery2Worker(wk *worker, pool *workerPool, job *model.Job) {
 			if err != nil {
 				return
 			}
-			cleanMDLInfo(d.sessPool, job.ID, d.etcdCli, job.State == model.JobStateSynced)
+			cleanMDLInfo(d.sessPool, job.ID, d.etcdCli, ownerID, job.State == model.JobStateSynced)
 			d.synced(job)
 
 			if RunInGoTest {

pkg/session/bootstrap.go

@@ -1093,11 +1093,15 @@ const (
 	// version 197
 	//   replace `mysql.tidb_mdl_view` table
 	version197 = 197
+
+	// version 198
+	//   add column `owner_id` for `mysql.tidb_mdl_info` table
+	version198 = 198
 )
 
 // currentBootstrapVersion is defined as a variable, so we can modify its value for testing.
 // please make sure this is the largest version
-var currentBootstrapVersion int64 = version197
+var currentBootstrapVersion int64 = version198
 
 // DDL owner key's expired time is ManagerSessionTTL seconds, we should wait the time and give more time to have a chance to finish it.
 var internalSQLTimeout = owner.ManagerSessionTTL + 15
@@ -1260,6 +1264,7 @@ var (
 		upgradeToVer195,
 		upgradeToVer196,
 		upgradeToVer197,
+		upgradeToVer198,
 	}
 )
 
@@ -3103,6 +3108,14 @@ func upgradeToVer197(s sessiontypes.Session, ver int64) {
 	doReentrantDDL(s, CreateMDLView)
 }
 
+func upgradeToVer198(s sessiontypes.Session, ver int64) {
+	if ver >= version198 {
+		return
+	}
+
+	doReentrantDDL(s, "ALTER TABLE mysql.tidb_mdl_info ADD COLUMN owner_id VARCHAR(64) NOT NULL DEFAULT '';", infoschema.ErrColumnExists)
+}
+
 func writeOOMAction(s sessiontypes.Session) {
 	comment := "oom-action is `log` by default in v3.0.x, `cancel` by default in v4.0.11+"
 	mustExecute(s, `INSERT HIGH_PRIORITY INTO %n.%n VALUES (%?, %?, %?) ON DUPLICATE KEY UPDATE VARIABLE_VALUE= %?`,

pkg/session/session.go

@@ -3150,7 +3150,8 @@ var (
 	mdlTable = `create table mysql.tidb_mdl_info(
 		job_id BIGINT NOT NULL PRIMARY KEY,
 		version BIGINT NOT NULL,
-		table_ids text(65535)
+		table_ids text(65535),
+		owner_id varchar(64) NOT NULL DEFAULT ''
 	);`
 )