feat: Add backoff to flush op (#13140)

docs/sources/configure/_index.md

@@ -1442,7 +1442,23 @@ lifecycler:
 # CLI flag: -ingester.flush-check-period
 [flush_check_period: <duration> | default = 30s]
 
-# The timeout before a flush is cancelled.
+flush_op_backoff:
+  # Minimum backoff period when a flush fails. Each concurrent flush has its own
+  # backoff, see `ingester.concurrent-flushes`.
+  # CLI flag: -ingester.flush-op-backoff-min-period
+  [min_period: <duration> | default = 10s]
+
+  # Maximum backoff period when a flush fails. Each concurrent flush has its own
+  # backoff, see `ingester.concurrent-flushes`.
+  # CLI flag: -ingester.flush-op-backoff-max-period
+  [max_period: <duration> | default = 1m]
+
+  # Maximum retries for failed flushes.
+  # CLI flag: -ingester.flush-op-backoff-retries
+  [max_retries: <int> | default = 10]
+
+# The timeout for an individual flush. Will be retried up to
+# `flush-op-backoff-retries` times.
 # CLI flag: -ingester.flush-op-timeout
 [flush_op_timeout: <duration> | default = 10m]
 

pkg/ingester/flush.go

@@ -7,15 +7,16 @@ import (
 	"sync"
 	"time"
 
+	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
+	"github.com/grafana/dskit/backoff"
+	"github.com/grafana/dskit/tenant"
 	"github.com/grafana/dskit/user"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/model/labels"
 	"golang.org/x/net/context"
 
-	"github.com/grafana/dskit/tenant"
-
 	"github.com/grafana/loki/pkg/chunkenc"
 	"github.com/grafana/loki/pkg/storage/chunk"
 	"github.com/grafana/loki/pkg/util"
@@ -126,8 +127,9 @@ func (i *Ingester) sweepStream(instance *instance, stream *stream, immediate boo
 }
 
 func (i *Ingester) flushLoop(j int) {
+	l := log.With(util_log.Logger, "loop", j)
 	defer func() {
-		level.Debug(util_log.Logger).Log("msg", "Ingester.flushLoop() exited")
+		level.Debug(l).Log("msg", "Ingester.flushLoop() exited")
 		i.flushQueuesDone.Done()
 	}()
 
@@ -138,9 +140,10 @@ func (i *Ingester) flushLoop(j int) {
 		}
 		op := o.(*flushOp)
 
-		err := i.flushUserSeries(op.userID, op.fp, op.immediate)
+		m := util_log.WithUserID(op.userID, l)
+		err := i.flushOp(m, op)
 		if err != nil {
-			level.Error(util_log.WithUserID(op.userID, util_log.Logger)).Log("msg", "failed to flush", "err", err)
+			level.Error(m).Log("msg", "failed to flush", "err", err)
 		}
 
 		// If we're exiting & we failed to flush, put the failed operation
@@ -152,7 +155,23 @@ func (i *Ingester) flushLoop(j int) {
 	}
 }
 
-func (i *Ingester) flushUserSeries(userID string, fp model.Fingerprint, immediate bool) error {
+func (i *Ingester) flushOp(l log.Logger, op *flushOp) error {
+	ctx, cancelFunc := context.WithCancel(context.Background())
+	defer cancelFunc()
+
+	b := backoff.New(ctx, i.cfg.FlushOpBackoff)
+	for b.Ongoing() {
+		err := i.flushUserSeries(ctx, op.userID, op.fp, op.immediate)
+		if err == nil {
+			break
+		}
+		level.Error(l).Log("msg", "failed to flush", "retries", b.NumRetries(), "err", err)
+		b.Wait()
+	}
+	return b.Err()
+}
+
+func (i *Ingester) flushUserSeries(ctx context.Context, userID string, fp model.Fingerprint, immediate bool) error {
 	instance, ok := i.getInstanceByID(userID)
 	if !ok {
 		return nil
@@ -166,9 +185,9 @@ func (i *Ingester) flushUserSeries(userID string, fp model.Fingerprint, immediat
 	lbs := labels.String()
 	level.Info(util_log.Logger).Log("msg", "flushing stream", "user", userID, "fp", fp, "immediate", immediate, "num_chunks", len(chunks), "labels", lbs)
 
-	ctx := user.InjectOrgID(context.Background(), userID)
-	ctx, cancel := context.WithTimeout(ctx, i.cfg.FlushOpTimeout)
-	defer cancel()
+	ctx = user.InjectOrgID(ctx, userID)
+	ctx, cancelFunc := context.WithTimeout(ctx, i.cfg.FlushOpTimeout)
+	defer cancelFunc()
 	err := i.flushChunks(ctx, fp, labels, chunks, chunkMtx)
 	if err != nil {
 		return fmt.Errorf("failed to flush chunks: %w, num_chunks: %d, labels: %s", err, len(chunks), lbs)

pkg/ingester/flush_test.go

@@ -1,6 +1,7 @@
 package ingester
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"sort"
@@ -100,6 +101,67 @@ func Benchmark_FlushLoop(b *testing.B) {
 	}
 }
 
+func Test_FlushOp(t *testing.T) {
+	t.Run("no error", func(t *testing.T) {
+		cfg := defaultIngesterTestConfig(t)
+		cfg.FlushOpBackoff.MinBackoff = time.Second
+		cfg.FlushOpBackoff.MaxBackoff = 10 * time.Second
+		cfg.FlushOpBackoff.MaxRetries = 1
+		cfg.FlushCheckPeriod = 100 * time.Millisecond
+
+		_, ing := newTestStore(t, cfg, nil)
+
+		ctx := user.InjectOrgID(context.Background(), "foo")
+		ins, err := ing.GetOrCreateInstance("foo")
+		require.NoError(t, err)
+
+		lbs := makeRandomLabels()
+		req := &logproto.PushRequest{Streams: []logproto.Stream{{
+			Labels:  lbs.String(),
+			Entries: entries(5, time.Now()),
+		}}}
+		require.NoError(t, ins.Push(ctx, req))
+
+		time.Sleep(cfg.FlushCheckPeriod)
+		require.NoError(t, ing.flushOp(gokitlog.NewNopLogger(), &flushOp{
+			immediate: true,
+			userID:    "foo",
+			fp:        ins.getHashForLabels(lbs),
+		}))
+	})
+
+	t.Run("max retries exceeded", func(t *testing.T) {
+		cfg := defaultIngesterTestConfig(t)
+		cfg.FlushOpBackoff.MinBackoff = time.Second
+		cfg.FlushOpBackoff.MaxBackoff = 10 * time.Second
+		cfg.FlushOpBackoff.MaxRetries = 1
+		cfg.FlushCheckPeriod = 100 * time.Millisecond
+
+		store, ing := newTestStore(t, cfg, nil)
+		store.onPut = func(_ context.Context, _ []chunk.Chunk) error {
+			return errors.New("failed to write chunks")
+		}
+
+		ctx := user.InjectOrgID(context.Background(), "foo")
+		ins, err := ing.GetOrCreateInstance("foo")
+		require.NoError(t, err)
+
+		lbs := makeRandomLabels()
+		req := &logproto.PushRequest{Streams: []logproto.Stream{{
+			Labels:  lbs.String(),
+			Entries: entries(5, time.Now()),
+		}}}
+		require.NoError(t, ins.Push(ctx, req))
+
+		time.Sleep(cfg.FlushCheckPeriod)
+		require.EqualError(t, ing.flushOp(gokitlog.NewNopLogger(), &flushOp{
+			immediate: true,
+			userID:    "foo",
+			fp:        ins.getHashForLabels(lbs),
+		}), "terminated after 1 retries")
+	})
+}
+
 func Test_Flush(t *testing.T) {
 	var (
 		store, ing = newTestStore(t, defaultIngesterTestConfig(t), nil)
@@ -295,6 +357,10 @@ func defaultIngesterTestConfig(t testing.TB) Config {
 
 	cfg := Config{}
 	flagext.DefaultValues(&cfg)
+	cfg.FlushOpBackoff.MinBackoff = 100 * time.Millisecond
+	cfg.FlushOpBackoff.MaxBackoff = 10 * time.Second
+	cfg.FlushOpBackoff.MaxRetries = 1
+	cfg.FlushOpTimeout = 15 * time.Second
 	cfg.FlushCheckPeriod = 99999 * time.Hour
 	cfg.MaxChunkIdle = 99999 * time.Hour
 	cfg.ConcurrentFlushes = 1

pkg/ingester/ingester.go

@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"github.com/go-kit/log/level"
+	"github.com/grafana/dskit/backoff"
 	"github.com/grafana/dskit/concurrency"
 	"github.com/grafana/dskit/modules"
 	"github.com/grafana/dskit/multierror"
@@ -80,6 +81,7 @@ type Config struct {
 
 	ConcurrentFlushes   int               `yaml:"concurrent_flushes"`
 	FlushCheckPeriod    time.Duration     `yaml:"flush_check_period"`
+	FlushOpBackoff      backoff.Config    `yaml:"flush_op_backoff"`
 	FlushOpTimeout      time.Duration     `yaml:"flush_op_timeout"`
 	RetainPeriod        time.Duration     `yaml:"chunk_retain_period"`
 	MaxChunkIdle        time.Duration     `yaml:"chunk_idle_period"`
@@ -123,7 +125,10 @@ func (cfg *Config) RegisterFlags(f *flag.FlagSet) {
 	f.IntVar(&cfg.MaxTransferRetries, "ingester.max-transfer-retries", 0, "Number of times to try and transfer chunks before falling back to flushing. If set to 0 or negative value, transfers are disabled.")
 	f.IntVar(&cfg.ConcurrentFlushes, "ingester.concurrent-flushes", 32, "How many flushes can happen concurrently from each stream.")
 	f.DurationVar(&cfg.FlushCheckPeriod, "ingester.flush-check-period", 30*time.Second, "How often should the ingester see if there are any blocks to flush. The first flush check is delayed by a random time up to 0.8x the flush check period. Additionally, there is +/- 1% jitter added to the interval.")
-	f.DurationVar(&cfg.FlushOpTimeout, "ingester.flush-op-timeout", 10*time.Minute, "The timeout before a flush is cancelled.")
+	f.DurationVar(&cfg.FlushOpBackoff.MinBackoff, "ingester.flush-op-backoff-min-period", 10*time.Second, "Minimum backoff period when a flush fails. Each concurrent flush has its own backoff, see `ingester.concurrent-flushes`.")
+	f.DurationVar(&cfg.FlushOpBackoff.MaxBackoff, "ingester.flush-op-backoff-max-period", time.Minute, "Maximum backoff period when a flush fails. Each concurrent flush has its own backoff, see `ingester.concurrent-flushes`.")
+	f.IntVar(&cfg.FlushOpBackoff.MaxRetries, "ingester.flush-op-backoff-retries", 10, "Maximum retries for failed flushes.")
+	f.DurationVar(&cfg.FlushOpTimeout, "ingester.flush-op-timeout", 10*time.Minute, "The timeout for an individual flush. Will be retried up to `flush-op-backoff-retries` times.")
 	f.DurationVar(&cfg.RetainPeriod, "ingester.chunks-retain-period", 0, "How long chunks should be retained in-memory after they've been flushed.")
 	f.DurationVar(&cfg.MaxChunkIdle, "ingester.chunks-idle-period", 30*time.Minute, "How long chunks should sit in-memory with no updates before being flushed if they don't hit the max block size. This means that half-empty chunks will still be flushed after a certain period as long as they receive no further activity.")
 	f.IntVar(&cfg.BlockSize, "ingester.chunks-block-size", 256*1024, "The targeted _uncompressed_ size in bytes of a chunk block When this threshold is exceeded the head block will be cut and compressed inside the chunk.")
@@ -151,8 +156,14 @@ func (cfg *Config) Validate() error {
 		return err
 	}
 
-	if cfg.MaxTransferRetries > 0 && cfg.WAL.Enabled {
-		return errors.New("the use of the write ahead log (WAL) is incompatible with chunk transfers. It's suggested to use the WAL. Please try setting ingester.max-transfer-retries to 0 to disable transfers")
+	if cfg.FlushOpBackoff.MinBackoff > cfg.FlushOpBackoff.MaxBackoff {
+		return errors.New("invalid flush op min backoff: cannot be larger than max backoff")
+	}
+	if cfg.FlushOpBackoff.MaxRetries <= 0 {
+		return fmt.Errorf("invalid flush op max retries: %d", cfg.FlushOpBackoff.MaxRetries)
+	}
+	if cfg.FlushOpTimeout <= 0 {
+		return fmt.Errorf("invalid flush op timeout: %s", cfg.FlushOpTimeout)
 	}
 
 	if cfg.IndexShards <= 0 {

pkg/ingester/ingester_test.go

@@ -11,6 +11,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/grafana/dskit/backoff"
 	"github.com/grafana/dskit/flagext"
 	"github.com/grafana/dskit/httpgrpc"
 	"github.com/grafana/dskit/middleware"
@@ -660,57 +661,119 @@ func TestIngester_asyncStoreMaxLookBack(t *testing.T) {
 
 func TestValidate(t *testing.T) {
 	for i, tc := range []struct {
-		in       Config
-		err      bool
-		expected Config
+		in          Config
+		expected    Config
+		expectedErr string
 	}{
 		{
 			in: Config{
-				MaxChunkAge:   time.Minute,
 				ChunkEncoding: chunkenc.EncGZIP.String(),
-				IndexShards:   index.DefaultIndexShards,
+				FlushOpBackoff: backoff.Config{
+					MinBackoff: 100 * time.Millisecond,
+					MaxBackoff: 10 * time.Second,
+					MaxRetries: 1,
+				},
+				FlushOpTimeout: 15 * time.Second,
+				IndexShards:    index.DefaultIndexShards,
+				MaxChunkAge:    time.Minute,
 			},
 			expected: Config{
+				ChunkEncoding: chunkenc.EncGZIP.String(),
+				FlushOpBackoff: backoff.Config{
+					MinBackoff: 100 * time.Millisecond,
+					MaxBackoff: 10 * time.Second,
+					MaxRetries: 1,
+				},
+				FlushOpTimeout: 15 * time.Second,
+				IndexShards:    index.DefaultIndexShards,
 				MaxChunkAge:    time.Minute,
-				ChunkEncoding:  chunkenc.EncGZIP.String(),
 				parsedEncoding: chunkenc.EncGZIP,
-				IndexShards:    index.DefaultIndexShards,
 			},
 		},
 		{
 			in: Config{
 				ChunkEncoding: chunkenc.EncSnappy.String(),
-				IndexShards:   index.DefaultIndexShards,
+				FlushOpBackoff: backoff.Config{
+					MinBackoff: 100 * time.Millisecond,
+					MaxBackoff: 10 * time.Second,
+					MaxRetries: 1,
+				},
+				FlushOpTimeout: 15 * time.Second,
+				IndexShards:    index.DefaultIndexShards,
 			},
 			expected: Config{
-				ChunkEncoding:  chunkenc.EncSnappy.String(),
-				parsedEncoding: chunkenc.EncSnappy,
+				ChunkEncoding: chunkenc.EncSnappy.String(),
+				FlushOpBackoff: backoff.Config{
+					MinBackoff: 100 * time.Millisecond,
+					MaxBackoff: 10 * time.Second,
+					MaxRetries: 1,
+				},
+				FlushOpTimeout: 15 * time.Second,
 				IndexShards:    index.DefaultIndexShards,
+				parsedEncoding: chunkenc.EncSnappy,
 			},
 		},
 		{
 			in: Config{
-				IndexShards:   index.DefaultIndexShards,
 				ChunkEncoding: "bad-enc",
+				FlushOpBackoff: backoff.Config{
+					MinBackoff: 100 * time.Millisecond,
+					MaxBackoff: 10 * time.Second,
+					MaxRetries: 1,
+				},
+				FlushOpTimeout: 15 * time.Second,
+				IndexShards:    index.DefaultIndexShards,
+			},
+			expectedErr: "invalid encoding: bad-enc, supported: none, gzip, lz4-64k, snappy, lz4-256k, lz4-1M, lz4, flate, zstd",
+		},
+		{
+			in: Config{
+				ChunkEncoding: chunkenc.EncGZIP.String(),
+				FlushOpBackoff: backoff.Config{
+					MinBackoff: 100 * time.Millisecond,
+					MaxBackoff: 10 * time.Second,
+				},
+				FlushOpTimeout: 15 * time.Second,
+				IndexShards:    index.DefaultIndexShards,
+				MaxChunkAge:    time.Minute,
+			},
+			expectedErr: "invalid flush op max retries: 0",
+		},
+		{
+			in: Config{
+				ChunkEncoding: chunkenc.EncGZIP.String(),
+				FlushOpBackoff: backoff.Config{
+					MinBackoff: 100 * time.Millisecond,
+					MaxBackoff: 10 * time.Second,
+					MaxRetries: 1,
+				},
+				IndexShards: index.DefaultIndexShards,
+				MaxChunkAge: time.Minute,
 			},
-			err: true,
+			expectedErr: "invalid flush op timeout: 0s",
 		},
 		{
 			in: Config{
-				MaxChunkAge:   time.Minute,
 				ChunkEncoding: chunkenc.EncGZIP.String(),
+				FlushOpBackoff: backoff.Config{
+					MinBackoff: 100 * time.Millisecond,
+					MaxBackoff: 10 * time.Second,
+					MaxRetries: 1,
+				},
+				FlushOpTimeout: 15 * time.Second,
+				MaxChunkAge:    time.Minute,
 			},
-			err: true,
+			expectedErr: "invalid ingester index shard factor: 0",
 		},
 	} {
 		t.Run(fmt.Sprint(i), func(t *testing.T) {
 			err := tc.in.Validate()
-			if tc.err {
-				require.NotNil(t, err)
-				return
+			if tc.expectedErr != "" {
+				require.EqualError(t, err, tc.expectedErr)
+			} else {
+				require.NoError(t, err)
+				require.Equal(t, tc.expected, tc.in)
 			}
-			require.Nil(t, err)
-			require.Equal(t, tc.expected, tc.in)
 		})
 	}
 }