chore(logging): Add entry's timestamp when rejected with `too far behind` (#12933)

Signed-off-by: Kaviraj <kavirajkanagaraj@gmail.com>

pkg/chunkenc/interface.go

@@ -24,6 +24,10 @@ var (
 )
 
 type errTooFarBehind struct {
+	// original timestmap of the entry itself.
+	entryTs time.Time
+
+	// cutoff is the oldest acceptable timstamp of the `stream` that entry belongs to.
 	cutoff time.Time
 }
 
@@ -32,12 +36,12 @@ func IsErrTooFarBehind(err error) bool {
 	return ok
 }
 
-func ErrTooFarBehind(cutoff time.Time) error {
-	return &errTooFarBehind{cutoff: cutoff}
+func ErrTooFarBehind(entryTs, cutoff time.Time) error {
+	return &errTooFarBehind{entryTs: entryTs, cutoff: cutoff}
 }
 
 func (m *errTooFarBehind) Error() string {
-	return "entry too far behind, oldest acceptable timestamp is: " + m.cutoff.Format(time.RFC3339)
+	return fmt.Sprintf("entry too far behind, entry timestamp is: %s, oldest acceptable timestamp is: %s", m.entryTs.Format(time.RFC3339), m.cutoff.Format(time.RFC3339))
 }
 
 func IsOutOfOrderErr(err error) bool {

pkg/chunkenc/interface_test.go

@@ -31,7 +31,9 @@ func TestParseEncoding(t *testing.T) {
 }
 
 func TestIsOutOfOrderErr(t *testing.T) {
-	for _, err := range []error{ErrOutOfOrder, ErrTooFarBehind(time.Now())} {
+	now := time.Now()
+
+	for _, err := range []error{ErrOutOfOrder, ErrTooFarBehind(now, now)} {
 		require.Equal(t, true, IsOutOfOrderErr(err))
 	}
 }

pkg/ingester/stream.go

@@ -394,7 +394,7 @@ func (s *stream) validateEntries(entries []logproto.Entry, isReplay, rateLimitWh
 		// The validity window for unordered writes is the highest timestamp present minus 1/2 * max-chunk-age.
 		cutoff := highestTs.Add(-s.cfg.MaxChunkAge / 2)
 		if !isReplay && s.unorderedWrites && !highestTs.IsZero() && cutoff.After(entries[i].Timestamp) {
-			failedEntriesWithError = append(failedEntriesWithError, entryWithError{&entries[i], chunkenc.ErrTooFarBehind(cutoff)})
+			failedEntriesWithError = append(failedEntriesWithError, entryWithError{&entries[i], chunkenc.ErrTooFarBehind(entries[i].Timestamp, cutoff)})
 			s.writeFailures.Log(s.tenant, fmt.Errorf("%w for stream %s", failedEntriesWithError[len(failedEntriesWithError)-1].e, s.labels))
 			outOfOrderSamples++
 			outOfOrderBytes += lineBytes

pkg/ingester/stream_test.go

@@ -84,8 +84,9 @@ func TestMaxReturnedStreamsErrors(t *testing.T) {
 			var expected bytes.Buffer
 			for i := 0; i < tc.expectErrs; i++ {
 				fmt.Fprintf(&expected,
-					"entry with timestamp %s ignored, reason: 'entry too far behind, oldest acceptable timestamp is: %s',\n",
+					"entry with timestamp %s ignored, reason: 'entry too far behind, entry timestamp is: %s, oldest acceptable timestamp is: %s',\n",
 					time.Unix(int64(i), 0).String(),
+					newLines[i].Timestamp.Format(time.RFC3339),
 					time.Unix(int64(numLogs), 0).Format(time.RFC3339),
 				)
 			}