lightning: fix forget to set lastRetryableErr when ingest RPC fail (#56345)

br/pkg/lightning/backend/local/BUILD.bazel

@@ -55,6 +55,7 @@ go_library(
         "//util/codec",
         "//util/engine",
         "//util/hack",
+        "//util/intest",
         "//util/mathutil",
         "//util/ranger",
         "@com_github_cockroachdb_pebble//:pebble",

br/pkg/lightning/backend/local/local.go

@@ -56,6 +56,7 @@
 	"github.com/pingcap/tidb/tablecodec"
 	"github.com/pingcap/tidb/util/codec"
 	"github.com/pingcap/tidb/util/engine"
+	"github.com/pingcap/tidb/util/intest"
 	"github.com/pingcap/tidb/util/mathutil"
 	"github.com/tikv/client-go/v2/oracle"
 	tikvclient "github.com/tikv/client-go/v2/tikv"
@@ -76,9 +77,6 @@
 	dialTimeout             = 5 * time.Minute
 	maxRetryTimes           = 5
 	defaultRetryBackoffTime = 3 * time.Second
-	// maxWriteAndIngestRetryTimes is the max retry times for write and ingest.
-	// A large retry times is for tolerating tikv cluster failures.
-	maxWriteAndIngestRetryTimes = 30
 
 	gRPCKeepAliveTime    = 10 * time.Minute
 	gRPCKeepAliveTimeout = 5 * time.Minute
@@ -111,6 +109,10 @@
 
 	errorEngineClosed     = errors.New("engine is closed")
 	maxRetryBackoffSecond = 30
+
+	// MaxWriteAndIngestRetryTimes is the max retry times for write and ingest.
+	// A large retry times is for tolerating tikv cluster failures.
+	MaxWriteAndIngestRetryTimes = 30
 )
 
 // ImportClientFactory is factory to create new import client for specific store.
@@ -1523,8 +1525,21 @@
 			switch job.stage {
 			case regionScanned, wrote:
 				job.retryCount++
-				if job.retryCount > maxWriteAndIngestRetryTimes {
-					firstErr.Set(job.lastRetryableErr)
+				if job.retryCount > MaxWriteAndIngestRetryTimes {
+					lastErr := job.lastRetryableErr
+					if lastErr == nil {
+						if intest.InTest {
+							panic("lastRetryableErr should not be nil")
+						}
+						lastErr = errors.New("retry limit exceeded")
+						log.FromContext(ctx).Error(
+							"lastRetryableErr should not be nil",
+							logutil.Key("startKey", job.keyRange.start),
+							logutil.Key("endKey", job.keyRange.end),
+							zap.Stringer("stage", job.stage),
+							zap.Error(lastErr))
+					}
+					firstErr.Set(lastErr)
 					workerCancel()
 					jobWg.Done()
 					continue

br/pkg/lightning/backend/local/local_test.go

@@ -1921,7 +1921,7 @@ func TestDoImport(t *testing.T) {
 				{
 					keyRange:   Range{start: []byte{'a'}, end: []byte{'b'}},
 					engine:     &Engine{},
-					retryCount: maxWriteAndIngestRetryTimes - 1,
+					retryCount: MaxWriteAndIngestRetryTimes - 1,
 					injected:   getSuccessInjectedBehaviour(),
 				},
 			},
@@ -1931,7 +1931,7 @@ func TestDoImport(t *testing.T) {
 				{
 					keyRange:   Range{start: []byte{'b'}, end: []byte{'c'}},
 					engine:     &Engine{},
-					retryCount: maxWriteAndIngestRetryTimes - 1,
+					retryCount: MaxWriteAndIngestRetryTimes - 1,
 					injected:   getSuccessInjectedBehaviour(),
 				},
 			},
@@ -1941,7 +1941,7 @@ func TestDoImport(t *testing.T) {
 				{
 					keyRange:   Range{start: []byte{'c'}, end: []byte{'d'}},
 					engine:     &Engine{},
-					retryCount: maxWriteAndIngestRetryTimes - 2,
+					retryCount: MaxWriteAndIngestRetryTimes - 2,
 					injected: []injectedBehaviour{
 						{
 							write: injectedWriteBehaviour{
@@ -1992,13 +1992,13 @@ func TestRegionJobResetRetryCounter(t *testing.T) {
 					keyRange:   Range{start: []byte{'c'}, end: []byte{'c', '2'}},
 					engine:     &Engine{},
 					injected:   getNeedRescanWhenIngestBehaviour(),
-					retryCount: maxWriteAndIngestRetryTimes,
+					retryCount: MaxWriteAndIngestRetryTimes,
 				},
 				{
 					keyRange:   Range{start: []byte{'c', '2'}, end: []byte{'d'}},
 					engine:     &Engine{},
 					injected:   getSuccessInjectedBehaviour(),
-					retryCount: maxWriteAndIngestRetryTimes,
+					retryCount: MaxWriteAndIngestRetryTimes,
 				},
 			},
 		},

br/pkg/lightning/backend/local/region_job.go

@@ -451,6 +451,7 @@
 			log.FromContext(ctx).Warn("meet underlying error, will retry ingest",
 				log.ShortError(err), logutil.SSTMetas(j.writeResult.sstMeta),
 				logutil.Region(j.region.Region), logutil.Leader(j.region.Leader))
+			j.lastRetryableErr = err
 			continue
 		}
 		canContinue, err := j.convertStageOnIngestError(resp)
@@ -501,6 +502,9 @@
 // doIngest send ingest commands to TiKV based on regionJob.writeResult.sstMeta.
 // When meet error, it will remove finished sstMetas before return.
 func (local *Backend) doIngest(ctx context.Context, j *regionJob) (*sst.IngestResponse, error) {
+	failpoint.Inject("doIngestFailed", func() {
+		failpoint.Return(nil, errors.New("injected error"))
+	})
 	clientFactory := local.importClientFactory
 	supportMultiIngest := local.supportMultiIngest
 	shouldCheckWriteStall := local.ShouldCheckWriteStall

tests/realtikvtest/addindextest/integration_test.go

@@ -565,3 +565,29 @@ func TestAddUniqueIndexDuplicatedError(t *testing.T) {
 	tk.MustExec("INSERT INTO `b1cce552` (`f5d9aecb`, `d9337060`, `4c74082f`, `9215adc3`, `85ad5a07`, `8c60260f`, `8069da7b`, `91e218e1`) VALUES ('2031-12-22 06:44:52', 'duplicatevalue', 2028, NULL, 846, 'N6QD1=@ped@owVoJx', '9soPM2d6H', 'Tv%'), ('2031-12-22 06:44:52', 'duplicatevalue', 2028, NULL, 9052, '_HWaf#gD!bw', '9soPM2d6H', 'Tv%');")
 	tk.MustGetErrCode("ALTER TABLE `b1cce552` ADD unique INDEX `65290727` (`4c74082f`, `d9337060`, `8069da7b`);", errno.ErrDupEntry)
 }
+
+func TestIssue55808(t *testing.T) {
+	store := realtikvtest.CreateMockStoreAndSetup(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("drop database if exists addindexlit;")
+	tk.MustExec("create database addindexlit;")
+	tk.MustExec("use addindexlit;")
+	tk.MustExec(`set global tidb_ddl_enable_fast_reorg=on;`)
+	tk.MustExec("set global tidb_enable_dist_task = off;")
+	tk.MustExec("set global tidb_ddl_error_count_limit = 0")
+
+	backup := local.MaxWriteAndIngestRetryTimes
+	local.MaxWriteAndIngestRetryTimes = 1
+	t.Cleanup(func() {
+		local.MaxWriteAndIngestRetryTimes = backup
+	})
+
+	tk.MustExec("create table t (a int primary key, b int);")
+	for i := 0; i < 4; i++ {
+		tk.MustExec(fmt.Sprintf("insert into t values (%d, %d);", i*10000, i*10000))
+	}
+	require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/br/pkg/lightning/backend/local/doIngestFailed", "return()"))
+	err := tk.ExecToErr("alter table t add index idx(a);")
+	require.ErrorContains(t, err, "injected error")
+	require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/br/pkg/lightning/backend/local/doIngestFailed"))
+}