ddl: fix unexpected delete ETCD value (pingcap#52504) (pingcap#52651)

close pingcap#47060, close pingcap#52335

Author: ti-chi-bot

ddl/ddl_worker.go

@@ -470,7 +470,7 @@ func (w *worker) registerMDLInfo(job *model.Job, ver int64) error {
 }
 
 // cleanMDLInfo cleans metadata lock info.
-func cleanMDLInfo(pool *sess.Pool, jobID int64, ec *clientv3.Client) {
+func cleanMDLInfo(pool *sess.Pool, jobID int64, ec *clientv3.Client, cleanETCD bool) {
 	if !variable.EnableMDL.Load() {
 		return
 	}
@@ -484,7 +484,7 @@ func cleanMDLInfo(pool *sess.Pool, jobID int64, ec *clientv3.Client) {
 		logutil.BgLogger().Warn("unexpected error when clean mdl info", zap.Int64("job ID", jobID), zap.Error(err))
 		return
 	}
-	if ec != nil {
+	if cleanETCD && ec != nil {
 		path := fmt.Sprintf("%s/%d/", util.DDLAllSchemaVersionsByJob, jobID)
 		_, err = ec.Delete(context.Background(), path, clientv3.WithPrefix())
 		if err != nil {

ddl/job_table.go

@@ -379,7 +379,7 @@ func (d *ddl) delivery2worker(wk *worker, pool *workerPool, job *model.Job) {
 						return
 					}
 					d.setAlreadyRunOnce(job.ID)
-					cleanMDLInfo(d.sessPool, job.ID, d.etcdCli)
+					cleanMDLInfo(d.sessPool, job.ID, d.etcdCli, job.State == model.JobStateSynced)
 					// Don't have a worker now.
 					return
 				}
@@ -419,7 +419,7 @@ func (d *ddl) delivery2worker(wk *worker, pool *workerPool, job *model.Job) {
 				logutil.BgLogger().Info("wait latest schema version error", zap.String("category", "ddl"), zap.Error(err))
 				return
 			}
-			cleanMDLInfo(d.sessPool, job.ID, d.etcdCli)
+			cleanMDLInfo(d.sessPool, job.ID, d.etcdCli, job.State == model.JobStateSynced)
 			d.synced(job)
 
 			if RunInGoTest {