[exporter/elasticsearch] Limit bulk request size to avoid 413 Entity Too Large

.chloggen/elasticsearchexporter_sync-bulk-indexer-flush-bytes.yaml

@@ -0,0 +1,31 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: elasticsearchexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Respect `flush::bytes` in sync bulk indexer, `flush::bytes` measures uncompressed size, change default `batcher::max_size_items` to `0`
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [36163]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+  Limit the bulk request size to roughly `flush::bytes` for sync bulk indexer.
+  Sync bulk indexer is used when `batcher::enabled` is either true or false. In order words, sync bulk indexer is not used when batcher config is undefined.
+  Change `flush::bytes` to always measure in uncompressed bytes.
+  Change default `batcher::max_size_items` to `0` as bulk request size limit is now more effectively enforced by `flush::bytes`.
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

exporter/elasticsearchexporter/README.md

@@ -89,15 +89,16 @@ The Elasticsearch exporter supports the common [`sending_queue` settings][export
 The Elasticsearch exporter supports the [common `batcher` settings](https://github.com/open-telemetry/opentelemetry-collector/blob/main/exporter/exporterbatcher/config.go).
 
 - `batcher`:
-  - `enabled` (default=unset): Enable batching of requests into a single bulk request.
-  - `min_size_items` (default=5000): Minimum number of log records / spans in the buffer to trigger a flush immediately.
-  - `max_size_items` (default=10000): Maximum number of log records / spans in a request.
-  - `flush_timeout` (default=30s): Maximum time of the oldest item spent inside the buffer, aka "max age of buffer". A flush will happen regardless of the size of content in buffer.
+  - `enabled` (default=unset): Enable batching of requests into 1 or more bulk requests. On a batcher flush, it is possible for a batched request to be translated to more than 1 bulk request due to `flush::bytes`.
+  - `min_size_items` (default=5000): Minimum number of log records / spans / data points in the batched request to immediately trigger a batcher flush.
+  - `max_size_items` (default=0): Maximum number of log records / spans / data points in a batched request. To limit bulk request size, configure `flush::bytes` instead. :warning: It is recommended to keep `max_size_items` as 0 as a non-zero value may lead to broken metrics grouping and indexing rejections.
+  - `flush_timeout` (default=30s): Maximum time of the oldest item spent inside the batcher buffer, aka "max age of batcher buffer". A batcher flush will happen regardless of the size of content in batcher buffer.
 
 By default, the exporter will perform its own buffering and batching, as configured through the
 `flush` config, and `batcher` will be unused. By setting `batcher::enabled` to either `true` or
-`false`, the exporter will not perform any of its own buffering or batching, and the `flush` config
-will be ignored. In a future release when the `batcher` config is stable, and has feature parity
+`false`, the exporter will not perform any of its own buffering or batching, and the `flush::interval` config
+will be ignored.
+In a future release when the `batcher` config is stable, and has feature parity
 with the exporter's existing `flush` config, it will be enabled by default.
 
 Using the common `batcher` functionality provides several benefits over the default behavior:
@@ -198,7 +199,7 @@ The behaviour of this bulk indexing can be configured with the following setting
 
 - `num_workers` (default=runtime.NumCPU()): Number of workers publishing bulk requests concurrently.
 - `flush`: Event bulk indexer buffer flush settings
-  - `bytes` (default=5000000): Write buffer flush size limit.
+  - `bytes` (default=5000000): Write buffer flush size limit before compression. A bulk request will be sent immediately when its buffer exceeds this limit. This value should be much lower than [Elasticsearch `http.max_content_length`](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-network.html#http-settings) config to avoid HTTP 413 Entity Too Large error. It is recommended to keep this value under 5MB.
   - `interval` (default=30s): Write buffer flush time limit.
 - `retry`: Elasticsearch bulk request retry settings
   - `enabled` (default=true): Enable/Disable request retry on error. Failed requests are retried with exponential backoff.
@@ -209,7 +210,7 @@ The behaviour of this bulk indexing can be configured with the following setting
   - `retry_on_status` (default=[429]): Status codes that trigger request or document level retries. Request level retry and document level retry status codes are shared and cannot be configured separately. To avoid duplicates, it defaults to `[429]`.
 
 > [!NOTE]
-> The `flush` config will be ignored when `batcher::enabled` config is explicitly set to `true` or `false`.
+> The `flush::interval` config will be ignored when `batcher::enabled` config is explicitly set to `true` or `false`.
 
 ### Elasticsearch node discovery
 

exporter/elasticsearchexporter/bulkindexer.go

@@ -88,6 +88,7 @@ func newSyncBulkIndexer(logger *zap.Logger, client *elasticsearch.Client, config
 	return &syncBulkIndexer{
 		config:       bulkIndexerConfig(client, config),
 		flushTimeout: config.Timeout,
+		flushBytes:   config.Flush.Bytes,
 		retryConfig:  config.Retry,
 		logger:       logger,
 	}
@@ -96,6 +97,7 @@ func newSyncBulkIndexer(logger *zap.Logger, client *elasticsearch.Client, config
 type syncBulkIndexer struct {
 	config       docappender.BulkIndexerConfig
 	flushTimeout time.Duration
+	flushBytes   int
 	retryConfig  RetrySettings
 	logger       *zap.Logger
 }
@@ -124,8 +126,17 @@ type syncBulkIndexerSession struct {
 }
 
 // Add adds an item to the sync bulk indexer session.
-func (s *syncBulkIndexerSession) Add(_ context.Context, index string, document io.WriterTo, dynamicTemplates map[string]string) error {
-	return s.bi.Add(docappender.BulkIndexerItem{Index: index, Body: document, DynamicTemplates: dynamicTemplates})
+func (s *syncBulkIndexerSession) Add(ctx context.Context, index string, document io.WriterTo, dynamicTemplates map[string]string) error {
+	err := s.bi.Add(docappender.BulkIndexerItem{Index: index, Body: document, DynamicTemplates: dynamicTemplates})
+	if err != nil {
+		return err
+	}
+	// flush bytes should operate on uncompressed length
+	// as Elasticsearch http.max_content_length measures uncompressed length.
+	if s.bi.UncompressedLen() >= s.s.flushBytes {
+		return s.Flush(ctx)
+	}
+	return nil
 }
 
 // End is a no-op.
@@ -170,16 +181,6 @@ func newAsyncBulkIndexer(logger *zap.Logger, client *elasticsearch.Client, confi
 		numWorkers = runtime.NumCPU()
 	}
 
-	flushInterval := config.Flush.Interval
-	if flushInterval == 0 {
-		flushInterval = 30 * time.Second
-	}
-
-	flushBytes := config.Flush.Bytes
-	if flushBytes == 0 {
-		flushBytes = 5e+6
-	}
-
 	pool := &asyncBulkIndexer{
 		wg:    sync.WaitGroup{},
 		items: make(chan docappender.BulkIndexerItem, config.NumWorkers),
@@ -195,9 +196,9 @@ func newAsyncBulkIndexer(logger *zap.Logger, client *elasticsearch.Client, confi
 		w := asyncBulkIndexerWorker{
 			indexer:       bi,
 			items:         pool.items,
-			flushInterval: flushInterval,
+			flushInterval: config.Flush.Interval,
 			flushTimeout:  config.Timeout,
-			flushBytes:    flushBytes,
+			flushBytes:    config.Flush.Bytes,
 			logger:        logger,
 			stats:         &pool.stats,
 		}
@@ -298,8 +299,9 @@ func (w *asyncBulkIndexerWorker) run() {
 				w.logger.Error("error adding item to bulk indexer", zap.Error(err))
 			}
 
-			// w.indexer.Len() can be either compressed or uncompressed bytes
-			if w.indexer.Len() >= w.flushBytes {
+			// flush bytes should operate on uncompressed length
+			// as Elasticsearch http.max_content_length measures uncompressed length.
+			if w.indexer.UncompressedLen() >= w.flushBytes {
 				w.flush()
 				flushTick.Reset(w.flushInterval)
 			}

exporter/elasticsearchexporter/bulkindexer_test.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"net/http"
 	"strings"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -122,6 +123,7 @@ func TestAsyncBulkIndexer_requireDataStream(t *testing.T) {
 			config: Config{
 				NumWorkers: 1,
 				Mapping:    MappingsSettings{Mode: MappingECS.String()},
+				Flush:      FlushSettings{Interval: time.Hour, Bytes: 1e+8},
 			},
 			wantRequireDataStream: false,
 		},
@@ -130,6 +132,7 @@ func TestAsyncBulkIndexer_requireDataStream(t *testing.T) {
 			config: Config{
 				NumWorkers: 1,
 				Mapping:    MappingsSettings{Mode: MappingOTel.String()},
+				Flush:      FlushSettings{Interval: time.Hour, Bytes: 1e+8},
 			},
 			wantRequireDataStream: true,
 		},
@@ -252,13 +255,15 @@ func TestAsyncBulkIndexer_logRoundTrip(t *testing.T) {
 			config: Config{
 				NumWorkers:   1,
 				ClientConfig: confighttp.ClientConfig{Compression: "none"},
+				Flush:        FlushSettings{Interval: time.Hour, Bytes: 1e+8},
 			},
 		},
 		{
 			name: "compression gzip",
 			config: Config{
 				NumWorkers:   1,
 				ClientConfig: confighttp.ClientConfig{Compression: "gzip"},
+				Flush:        FlushSettings{Interval: time.Hour, Bytes: 1e+8},
 			},
 		},
 	}
@@ -316,3 +321,28 @@ func runBulkIndexerOnce(t *testing.T, config *Config, client *elasticsearch.Clie
 
 	return bulkIndexer
 }
+
+func TestSyncBulkIndexer_flushBytes(t *testing.T) {
+	var reqCnt atomic.Int64
+	cfg := Config{NumWorkers: 1, Flush: FlushSettings{Interval: time.Hour, Bytes: 1}}
+	client, err := elasticsearch.NewClient(elasticsearch.Config{Transport: &mockTransport{
+		RoundTripFunc: func(r *http.Request) (*http.Response, error) {
+			if r.URL.Path == "/_bulk" {
+				reqCnt.Add(1)
+			}
+			return &http.Response{
+				Header: http.Header{"X-Elastic-Product": []string{"Elasticsearch"}},
+				Body:   io.NopCloser(strings.NewReader(successResp)),
+			}, nil
+		},
+	}})
+	require.NoError(t, err)
+
+	bi := newSyncBulkIndexer(zap.NewNop(), client, &cfg)
+	session, err := bi.StartSession(context.Background())
+	require.NoError(t, err)
+
+	assert.NoError(t, session.Add(context.Background(), "foo", strings.NewReader(`{"foo": "bar"}`), nil))
+	assert.Equal(t, int64(1), reqCnt.Load()) // flush due to flush::bytes
+	assert.NoError(t, bi.Close(context.Background()))
+}

exporter/elasticsearchexporter/config_test.go

@@ -93,7 +93,8 @@ func TestConfig(t *testing.T) {
 					OnStart: true,
 				},
 				Flush: FlushSettings{
-					Bytes: 10485760,
+					Bytes:    10485760,
+					Interval: 30 * time.Second,
 				},
 				Retry: RetrySettings{
 					Enabled:         true,
@@ -117,7 +118,7 @@ func TestConfig(t *testing.T) {
 						MinSizeItems: 5000,
 					},
 					MaxSizeConfig: exporterbatcher.MaxSizeConfig{
-						MaxSizeItems: 10000,
+						MaxSizeItems: 0,
 					},
 				},
 			},
@@ -164,7 +165,8 @@ func TestConfig(t *testing.T) {
 					OnStart: true,
 				},
 				Flush: FlushSettings{
-					Bytes: 10485760,
+					Bytes:    10485760,
+					Interval: 30 * time.Second,
 				},
 				Retry: RetrySettings{
 					Enabled:         true,
@@ -188,7 +190,7 @@ func TestConfig(t *testing.T) {
 						MinSizeItems: 5000,
 					},
 					MaxSizeConfig: exporterbatcher.MaxSizeConfig{
-						MaxSizeItems: 10000,
+						MaxSizeItems: 0,
 					},
 				},
 			},
@@ -235,7 +237,8 @@ func TestConfig(t *testing.T) {
 					OnStart: true,
 				},
 				Flush: FlushSettings{
-					Bytes: 10485760,
+					Bytes:    10485760,
+					Interval: 30 * time.Second,
 				},
 				Retry: RetrySettings{
 					Enabled:         true,
@@ -259,7 +262,7 @@ func TestConfig(t *testing.T) {
 						MinSizeItems: 5000,
 					},
 					MaxSizeConfig: exporterbatcher.MaxSizeConfig{
-						MaxSizeItems: 10000,
+						MaxSizeItems: 0,
 					},
 				},
 			},

exporter/elasticsearchexporter/factory.go

@@ -91,9 +91,13 @@ func createDefaultConfig() component.Config {
 				MinSizeItems: 5000,
 			},
 			MaxSizeConfig: exporterbatcher.MaxSizeConfig{
-				MaxSizeItems: 10000,
+				MaxSizeItems: 0,
 			},
 		},
+		Flush: FlushSettings{
+			Bytes:    5e+6,
+			Interval: 30 * time.Second,
+		},
 	}
 }