Removed deprecated untyped record from chunks WAL

Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## master / unreleased
 
+* [CHANGE] Ingester: Removed deprecated untyped record from chunks WAL. Only if you are running `v1.0` or below, it is recommended to first upgrade to `v1.1`/`v1.2`/`v1.3` and run it for a day before upgrading to `v1.4` to avoid data loss. #3115
 * [CHANGE] Increase the default Cassandra client replication factor to 3. #3007
 * [CHANGE] Experimental blocks storage: removed the support to transfer blocks between ingesters on shutdown. When running the Cortex blocks storage, ingesters are expected to run with a persistent disk. The following metrics have been removed: #2996
   * `cortex_ingester_sent_files`

pkg/ingester/wal.go

@@ -65,12 +65,6 @@ type WAL interface {
 type RecordType byte
 
 const (
-	// Currently we also support the old records without a type header.
-	// For that, we assume the record type does not cross 7 as the proto unmarshalling
-	// will produce an error if the first byte is less than 7 (thus we know its not the old record).
-	// The old record will be removed in the future releases, hence the record type should not cross
-	// '7' till then.
-
 	// WALRecordSeries is the type for the WAL record on Prometheus TSDB record for series.
 	WALRecordSeries RecordType = 1
 	// WALRecordSamples is the type for the WAL record based on Prometheus TSDB record for samples.
@@ -843,7 +837,6 @@ func processWAL(startSegment int, userStates *userStates, params walRecoveryPara
 
 	var (
 		capturedErr error
-		record      = &Record{}
 		walRecord   = &WALRecord{}
 		lp          labelPairs
 	)
@@ -857,51 +850,30 @@ Loop:
 		default:
 		}
 
-		record.Samples = record.Samples[:0]
-		record.Labels = record.Labels[:0]
-		// Only one of 'record' or 'walRecord' will have the data.
-		if err := decodeWALRecord(reader.Record(), record, walRecord); err != nil {
+		if err := decodeWALRecord(reader.Record(), walRecord); err != nil {
 			// We don't return here in order to close/drain all the channels and
 			// make sure all goroutines exit.
 			capturedErr = err
 			break Loop
 		}
 
-		if len(record.Labels) > 0 || len(walRecord.Series) > 0 {
-
-			var userID string
-			if len(walRecord.Series) > 0 {
-				userID = walRecord.UserID
-			} else {
-				userID = record.UserId
-			}
+		if len(walRecord.Series) > 0 {
+			userID := walRecord.UserID
 
 			state := userStates.getOrCreate(userID)
 
-			createSeries := func(fingerprint model.Fingerprint, lbls labelPairs) error {
-				_, ok := state.fpToSeries.get(fingerprint)
+			for _, s := range walRecord.Series {
+				fp := model.Fingerprint(s.Ref)
+				_, ok := state.fpToSeries.get(fp)
 				if ok {
-					return nil
-				}
-				_, err := state.createSeriesWithFingerprint(fingerprint, lbls, nil, true)
-				return err
-			}
-
-			for _, labels := range record.Labels {
-				if err := createSeries(model.Fingerprint(labels.Fingerprint), labels.Labels); err != nil {
-					// We don't return here in order to close/drain all the channels and
-					// make sure all goroutines exit.
-					capturedErr = err
-					break Loop
+					continue
 				}
-			}
 
-			for _, s := range walRecord.Series {
 				lp = lp[:0]
 				for _, l := range s.Labels {
 					lp = append(lp, client.LabelAdapter(l))
 				}
-				if err := createSeries(model.Fingerprint(s.Ref), lp); err != nil {
+				if _, err := state.createSeriesWithFingerprint(fp, lp, nil, true); err != nil {
 					// We don't return here in order to close/drain all the channels and
 					// make sure all goroutines exit.
 					capturedErr = err
@@ -914,20 +886,12 @@ Loop:
 		// With O(300 * #cores) in-flight sample batches, large scrapes could otherwise
 		// cause thousands of very large in flight buffers occupying large amounts
 		// of unused memory.
-		for len(record.Samples) > 0 || len(walRecord.Samples) > 0 {
+		walRecordSamples := walRecord.Samples
+		for len(walRecordSamples) > 0 {
 			m := 5000
-			var userID string
-			if len(record.Samples) > 0 {
-				userID = record.UserId
-				if len(record.Samples) < m {
-					m = len(record.Samples)
-				}
-			}
-			if len(walRecord.Samples) > 0 {
-				userID = walRecord.UserID
-				if len(walRecord.Samples) < m {
-					m = len(walRecord.Samples)
-				}
+			userID := walRecord.UserID
+			if len(walRecordSamples) < m {
+				m = len(walRecordSamples)
 			}
 
 			for i := 0; i < params.numWorkers; i++ {
@@ -949,21 +913,9 @@ Loop:
 				}
 			}
 
-			if len(record.Samples) > 0 {
-				for _, sam := range record.Samples[:m] {
-					mod := sam.Fingerprint % uint64(params.numWorkers)
-					shards[mod].samples = append(shards[mod].samples, tsdb_record.RefSample{
-						Ref: sam.Fingerprint,
-						T:   int64(sam.Timestamp),
-						V:   sam.Value,
-					})
-				}
-			}
-			if len(walRecord.Samples) > 0 {
-				for _, sam := range walRecord.Samples[:m] {
-					mod := sam.Ref % uint64(params.numWorkers)
-					shards[mod].samples = append(shards[mod].samples, sam)
-				}
+			for _, sam := range walRecordSamples[:m] {
+				mod := sam.Ref % uint64(params.numWorkers)
+				shards[mod].samples = append(shards[mod].samples, sam)
 			}
 
 			for i := 0; i < params.numWorkers; i++ {
@@ -972,12 +924,7 @@ Loop:
 				}
 			}
 
-			if len(record.Samples) > 0 {
-				record.Samples = record.Samples[m:]
-			}
-			if len(walRecord.Samples) > 0 {
-				walRecord.Samples = walRecord.Samples[m:]
-			}
+			walRecordSamples = walRecordSamples[m:]
 		}
 	}
 
@@ -1171,7 +1118,7 @@ func (record *WALRecord) encodeSamples(b []byte) []byte {
 	return encoded
 }
 
-func decodeWALRecord(b []byte, rec *Record, walRec *WALRecord) (err error) {
+func decodeWALRecord(b []byte, walRec *WALRecord) (err error) {
 	var (
 		userID   string
 		dec      tsdb_record.Decoder
@@ -1192,23 +1139,21 @@ func decodeWALRecord(b []byte, rec *Record, walRec *WALRecord) (err error) {
 		userID = decbuf.UvarintStr()
 		rseries, err = dec.Series(decbuf.B, walRec.Series)
 	default:
-		// The legacy proto record will have it's first byte >7.
-		// Hence it does not match any of the existing record types.
-		err = proto.Unmarshal(b, rec)
-		return err
+		return errors.New("unknown record type")
 	}
 
 	// We reach here only if its a record with type header.
 	if decbuf.Err() != nil {
 		return decbuf.Err()
 	}
 
-	if err == nil {
-		// There was no error decoding the records with type headers.
-		walRec.UserID = userID
-		walRec.Samples = rsamples
-		walRec.Series = rseries
+	if err != nil {
+		return err
 	}
 
-	return err
+	walRec.UserID = userID
+	walRec.Samples = rsamples
+	walRec.Series = rseries
+
+	return nil
 }