*: caller can use a fixed TS for fast reorg

pkg/ddl/backfilling_dist_executor.go

@@ -59,6 +59,7 @@ type BackfillSubTaskMeta struct {
 	RangeSplitKeys [][]byte `json:"range_split_keys,omitempty"`
 	DataFiles      []string `json:"data-files,omitempty"`
 	StatFiles      []string `json:"stat-files,omitempty"`
+	TS             uint64   `json:"ts,omitempty"`
 	// Each group of MetaGroups represents a different index kvs meta.
 	MetaGroups []*external.SortedKVMeta `json:"meta_groups,omitempty"`
 	// Only used for adding one single index.

pkg/ddl/backfilling_dist_scheduler.go

@@ -42,6 +42,7 @@ import (
 	"github.com/pingcap/tidb/pkg/table"
 	"github.com/pingcap/tidb/pkg/util/backoff"
 	tidblogutil "github.com/pingcap/tidb/pkg/util/logutil"
+	"github.com/tikv/client-go/v2/oracle"
 	"github.com/tikv/client-go/v2/tikv"
 	"go.uber.org/zap"
 )
@@ -405,6 +406,16 @@ func splitSubtaskMetaForOneKVMetaGroup(
 		// Skip global sort for empty table.
 		return nil, nil
 	}
+	pdCli := store.GetPDClient()
+	p, l, err := pdCli.GetTS(ctx)
+	if err != nil {
+		return nil, err
+	}
+	ts := oracle.ComposeTS(p, l)
+	failpoint.Inject("mockTSForGlobalSort", func(val failpoint.Value) {
+		i := val.(int)
+		ts = uint64(i)
+	})
 	splitter, err := getRangeSplitter(
 		ctx, store, cloudStorageURI, int64(kvMeta.TotalKVSize), instanceCnt, kvMeta.MultipleFilesStats, logger)
 	if err != nil {
@@ -446,6 +457,7 @@ func splitSubtaskMetaForOneKVMetaGroup(
 			DataFiles:      dataFiles,
 			StatFiles:      statFiles,
 			RangeSplitKeys: rangeSplitKeys,
+			TS:             ts,
 		}
 		metaBytes, err := json.Marshal(m)
 		if err != nil {

pkg/ddl/backfilling_import_cloud.go

@@ -95,6 +95,7 @@ func (m *cloudImportExecutor) RunSubtask(ctx context.Context, subtask *proto.Sub
 			TotalKVCount:  0,
 			CheckHotspot:  true,
 		},
+		TS: sm.TS,
 	}, engineUUID)
 	if err != nil {
 		return err

pkg/ddl/ingest/BUILD.bazel

@@ -48,6 +48,7 @@ go_library(
         "@com_github_google_uuid//:uuid",
         "@com_github_pingcap_errors//:errors",
         "@com_github_pingcap_failpoint//:failpoint",
+        "@com_github_tikv_client_go_v2//oracle",
         "@com_github_tikv_client_go_v2//util",
         "@com_github_tikv_pd_client//:client",
         "@io_etcd_go_etcd_client_v3//:client",
@@ -88,6 +89,8 @@ go_test(
         "@com_github_pingcap_failpoint//:failpoint",
         "@com_github_stretchr_testify//assert",
         "@com_github_stretchr_testify//require",
+        "@com_github_tikv_client_go_v2//oracle",
+        "@com_github_tikv_pd_client//:client",
         "@org_uber_go_goleak//:goleak",
     ],
 )

pkg/ddl/ingest/backend.go

@@ -250,7 +250,7 @@ func (bc *litBackendCtx) unsafeImportAndReset(ei *engineInfo) error {
 		return err
 	}
 
-	err := bc.backend.ResetEngine(bc.ctx, ei.uuid)
+	err := bc.backend.ResetEngineSkipAllocTS(bc.ctx, ei.uuid)
 	if err != nil {
 		logutil.Logger(bc.ctx).Error(LitErrResetEngineFail, zap.Int64("index ID", ei.indexID))
 		err1 := ei.closedEngine.Cleanup(bc.ctx)
@@ -262,13 +262,35 @@ func (bc *litBackendCtx) unsafeImportAndReset(ei *engineInfo) error {
 		ei.closedEngine = nil
 		return err
 	}
+
+	mgr := bc.GetCheckpointManager()
+	if mgr == nil {
+		// disttask case, no need to refresh TS.
+		return nil
+	}
+
+	// for local disk case, we need to refresh TS because duplicate detection
+	// requires each ingest to have a unique TS.
+	//
+	// TODO(lance6716): there's still a chance that data is imported but because of
+	// checkpoint is low-watermark, the data will still be imported again with
+	// another TS after failover. Need to refine the checkpoint mechanism.
+	newTS, err := mgr.refreshTSAndUpdateCP()
+	if err != nil {
+		return errors.Trace(err)
+	}
+	ei.openedEngine.SetTS(newTS)
 	return nil
 }
 
 // ForceSyncFlagForTest is a flag to force sync only for test.
 var ForceSyncFlagForTest = false
 
 func (bc *litBackendCtx) checkFlush(mode FlushMode) (shouldFlush bool, shouldImport bool) {
+	failpoint.Inject("forceSyncFlagForTest", func() {
+		// used in a manual test
+		ForceSyncFlagForTest = true
+	})
 	if mode == FlushModeForceFlushAndImport || ForceSyncFlagForTest {
 		return true, true
 	}