ddl: use latest PD address to register lightning (#48687)

ddl/index.go

@@ -831,7 +831,24 @@ func doReorgWorkForCreateIndex(w *worker, d *ddlCtx, t *meta.Meta, job *model.Jo
 				job.RowCount = 0
 				return false, ver, nil
 			}
-			bc, err = ingest.LitBackCtxMgr.Register(w.ctx, indexInfo.Unique, job.ID, job.ReorgMeta.SQLMode)
+			var pdLeaderAddr string
+			if d != nil {
+				store, ok2 := d.store.(tikv.Storage)
+				if ok2 {
+					pdLeaderAddr = store.GetRegionCache().PDClient().GetLeaderAddr()
+				}
+				// happens in unit tests
+				if !ok2 || pdLeaderAddr == "mockpd" {
+					pdLeaderAddr = config.GetGlobalConfig().Path
+				}
+			}
+			bc, err = ingest.LitBackCtxMgr.Register(
+				w.ctx,
+				indexInfo.Unique,
+				job.ID,
+				job.ReorgMeta.SQLMode,
+				pdLeaderAddr,
+			)
 			if err != nil {
 				err = tryFallbackToTxnMerge(job, err)
 				return false, ver, errors.Trace(err)

ddl/ingest/backend_mgr.go

@@ -48,7 +48,13 @@ func (m *backendCtxManager) init(memRoot MemRoot, diskRoot DiskRoot) {
 }
 
 // Register creates a new backend and registers it to the backend context.
-func (m *backendCtxManager) Register(ctx context.Context, unique bool, jobID int64, _ mysql.SQLMode) (*BackendContext, error) {
+func (m *backendCtxManager) Register(
+	ctx context.Context,
+	unique bool,
+	jobID int64,
+	_ mysql.SQLMode,
+	pdAddr string,
+) (*BackendContext, error) {
 	bc, exist := m.Load(jobID)
 	if !exist {
 		m.memRoot.RefreshConsumption()
@@ -61,6 +67,7 @@ func (m *backendCtxManager) Register(ctx context.Context, unique bool, jobID int
 			logutil.BgLogger().Warn(LitWarnConfigError, zap.Int64("job ID", jobID), zap.Error(err))
 			return nil, err
 		}
+		cfg.TiDB.PdAddr = pdAddr
 		bd, err := createLocalBackend(ctx, cfg, glueLit{})
 		if err != nil {
 			logutil.BgLogger().Error(LitErrCreateBackendFail, zap.Int64("job ID", jobID), zap.Error(err))

ddl/ingest/config.go

@@ -51,7 +51,6 @@ func generateLightningConfig(memRoot MemRoot, jobID int64, unique bool) (*config
 	} else {
 		cfg.TikvImporter.DuplicateResolution = config.DupeResAlgNone
 	}
-	cfg.TiDB.PdAddr = tidbCfg.Path
 	cfg.TiDB.Host = "127.0.0.1"
 	cfg.TiDB.StatusPort = int(tidbCfg.Status.StatusPort)
 	// Set TLS related information