introduces "entry too far behind" instrumentation for unordered writes (

#4592)

pkg/chunkenc/interface.go

@@ -17,11 +17,16 @@ import (
 var (
 	ErrChunkFull       = errors.New("chunk full")
 	ErrOutOfOrder      = errors.New("entry out of order")
+	ErrTooFarBehind    = errors.New("entry too far behind")
 	ErrInvalidSize     = errors.New("invalid size")
 	ErrInvalidFlag     = errors.New("invalid flag")
 	ErrInvalidChecksum = errors.New("invalid chunk checksum")
 )
 
+func IsOutOfOrderErr(err error) bool {
+	return err == ErrOutOfOrder || err == ErrTooFarBehind
+}
+
 // Encoding is the identifier for a chunk encoding.
 type Encoding byte
 

pkg/chunkenc/interface_test.go

@@ -1,6 +1,10 @@
 package chunkenc
 
-import "testing"
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
 
 func TestParseEncoding(t *testing.T) {
 	tests := []struct {
@@ -24,3 +28,9 @@ func TestParseEncoding(t *testing.T) {
 		})
 	}
 }
+
+func TestIsOutOfOrderErr(t *testing.T) {
+	for _, err := range []error{ErrOutOfOrder, ErrTooFarBehind} {
+		require.Equal(t, true, IsOutOfOrderErr(err))
+	}
+}

pkg/ingester/stream.go

@@ -209,8 +209,12 @@ func (s *stream) Push(
 	var rateLimitedSamples, rateLimitedBytes int
 	defer func() {
 		if outOfOrderSamples > 0 {
-			validation.DiscardedSamples.WithLabelValues(validation.OutOfOrder, s.tenant).Add(float64(outOfOrderSamples))
-			validation.DiscardedBytes.WithLabelValues(validation.OutOfOrder, s.tenant).Add(float64(outOfOrderBytes))
+			name := validation.OutOfOrder
+			if s.unorderedWrites {
+				name = validation.TooFarBehind
+			}
+			validation.DiscardedSamples.WithLabelValues(name, s.tenant).Add(float64(outOfOrderSamples))
+			validation.DiscardedBytes.WithLabelValues(name, s.tenant).Add(float64(outOfOrderBytes))
 		}
 		if rateLimitedSamples > 0 {
 			validation.DiscardedSamples.WithLabelValues(validation.StreamRateLimit, s.tenant).Add(float64(rateLimitedSamples))
@@ -253,12 +257,12 @@ func (s *stream) Push(
 
 		// The validity window for unordered writes is the highest timestamp present minus 1/2 * max-chunk-age.
 		if s.unorderedWrites && !s.highestTs.IsZero() && s.highestTs.Add(-s.cfg.MaxChunkAge/2).After(entries[i].Timestamp) {
-			failedEntriesWithError = append(failedEntriesWithError, entryWithError{&entries[i], chunkenc.ErrOutOfOrder})
+			failedEntriesWithError = append(failedEntriesWithError, entryWithError{&entries[i], chunkenc.ErrTooFarBehind})
 			outOfOrderSamples++
 			outOfOrderBytes += len(entries[i].Line)
 		} else if err := chunk.chunk.Append(&entries[i]); err != nil {
 			failedEntriesWithError = append(failedEntriesWithError, entryWithError{&entries[i], err})
-			if err == chunkenc.ErrOutOfOrder {
+			if chunkenc.IsOutOfOrderErr(err) {
 				outOfOrderSamples++
 				outOfOrderBytes += len(entries[i].Line)
 			}
@@ -324,11 +328,12 @@ func (s *stream) Push(
 	if len(failedEntriesWithError) > 0 {
 		lastEntryWithErr := failedEntriesWithError[len(failedEntriesWithError)-1]
 		_, ok := lastEntryWithErr.e.(*validation.ErrStreamRateLimit)
-		if lastEntryWithErr.e != chunkenc.ErrOutOfOrder && !ok {
+		outOfOrder := chunkenc.IsOutOfOrderErr(lastEntryWithErr.e)
+		if !outOfOrder && !ok {
 			return bytesAdded, lastEntryWithErr.e
 		}
 		var statusCode int
-		if lastEntryWithErr.e == chunkenc.ErrOutOfOrder {
+		if outOfOrder {
 			statusCode = http.StatusBadRequest
 		}
 		if ok {

pkg/ingester/stream_test.go

@@ -77,7 +77,7 @@ 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 out of order' for stream: {foo=\"bar\"},\n",
+					"entry with timestamp %s ignored, reason: 'entry too far behind' for stream: {foo=\"bar\"},\n",
 					time.Unix(int64(i), 0).String(),
 				)
 			}

pkg/validation/validate.go

@@ -31,6 +31,7 @@ const (
 	// rather than the overall ingestion rate limit.
 	StreamRateLimit = "per_stream_rate_limit"
 	OutOfOrder      = "out_of_order"
+	TooFarBehind    = "too_far_behind"
 	// GreaterThanMaxSampleAge is a reason for discarding log lines which are older than the current time - `reject_old_samples_max_age`
 	GreaterThanMaxSampleAge         = "greater_than_max_sample_age"
 	GreaterThanMaxSampleAgeErrorMsg = "entry for stream '%s' has timestamp too old: %v"