log-backup: set gc disable when restore log

br/pkg/task/stream.go

@@ -458,6 +458,23 @@ func (s *streamMgr) checkStreamStartEnable(g glue.Glue) error {
 	return nil
 }
 
+// SetGcStatus sets status of GC enabled or disabled.
+func SetGcStatus(g glue.Glue, store kv.Storage, enable bool) error {
+	se, err := g.CreateSession(store)
+	if err != nil {
+		return errors.Trace(err)
+	}
+
+	execCtx := se.GetSessionCtx().(sqlexec.RestrictedSQLExecutor)
+	if err = utils.SetGcEnableStatus(execCtx, enable); err != nil {
+		log.Warn("failed to set gc status", zap.Bool("target-gc-status", enable), zap.Error(err))
+		return errors.Trace(err)
+	}
+
+	log.Info("set gc status", zap.Bool("enabled", enable))
+	return nil
+}
+
 // RunStreamCommand run all kinds of `stream task`
 func RunStreamCommand(
 	ctx context.Context,
@@ -1142,6 +1159,16 @@ func restoreStream(
 	// Always run the post-work even on error, so we don't stuck in the import
 	// mode or emptied schedulers
 	defer restorePostWork(ctx, client, restoreSchedulers)
+	// It need disable GC in TiKV when piTR.
+	// because the process of PITR is concurrent and kv events isn't sorted by tso.
+	if err = SetGcStatus(g, mgr.GetStorage(), false); err != nil {
+		return errors.Trace(err)
+	}
+	defer func() {
+		if err = SetGcStatus(g, mgr.GetStorage(), true); err != nil {
+			log.Info("failed to set gc enabled", zap.Error(err))
+		}
+	}()
 
 	err = client.InstallLogFileManager(ctx, cfg.StartTS, cfg.RestoreTS)
 	if err != nil {

br/pkg/utils/db.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/pingcap/errors"
 	"github.com/pingcap/log"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/sessionctx"
@@ -98,6 +99,20 @@ func IsLogBackupEnabled(ctx sqlexec.RestrictedSQLExecutor) (bool, error) {
 	return true, nil
 }
 
+// SetGcEnableStatus sets the status of GC.
+// gc.ratio-threshold = -1.0, which represents disable gc in TiKV.
+// gc.ratio-threshold = 1.1 is the default value in TiKV.
+func SetGcEnableStatus(ctx sqlexec.RestrictedSQLExecutor, enable bool) error {
+	ratio := 1.1
+	if !enable {
+		ratio = -1.0
+	}
+
+	internalCtx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnBR)
+	_, _, err := ctx.ExecRestrictedSQL(internalCtx, nil, "set config tikv `gc.ratio-threshold`=%?", ratio)
+	return errors.Trace(err)
+}
+
 // LogBackupTaskCountInc increases the count of log backup task.
 func LogBackupTaskCountInc() {
 	LogBackupTaskMutex.Lock()