Enable queueing, retry, timeout for Kafka exporter

exporter/kafkaexporter/README.md

@@ -12,10 +12,25 @@ The following settings are required:
 The following settings can be optionally configured:
 - `brokers` (default = localhost:9092): The list of kafka brokers
 - `topic` (default = otlp_spans): The name of the kafka topic to export to
-- `metadata.full` (default = true): Whether to maintain a full set of metadata. 
+- `metadata`
+  - `full` (default = true): Whether to maintain a full set of metadata. 
                                     When disabled the client does not make the initial request to broker at the startup.
-- `metadata.retry.max` (default = 3): The number of retries to get metadata
-- `metadata.retry.backoff` (default = 250ms): How long to wait between metadata retries
+  - `retry`
+    - `max` (default = 3): The number of retries to get metadata
+    - `backoff` (default = 250ms): How long to wait between metadata retries
+- `timeout` (default = 5s): Is the timeout for every attempt to send data to the backend.
+- `retry_on_failure`
+  - `enabled` (default = true)
+  - `initial_interval` (default = 5s): Time to wait after the first failure before retrying; ignored if `enabled` is `false`
+  - `max_interval` (default = 30s): Is the upper bound on backoff; ignored if `enabled` is `false`
+  - `max_elapsed_time` (default = 120s): Is the maximum amount of time spent trying to send a batch; ignored if `enabled` is `false`
+- `sending_queue`
+  - `enabled` (default = false)
+  - `num_consumers` (default = 10): Number of consumers that dequeue batches; ignored if `enabled` is `false`
+  - `queue_size` (default = 5000): Maximum number of batches kept in memory before dropping data; ignored if `enabled` is `false`;
+  User should calculate this as `num_seconds * requests_per_second` where:
+    - `num_seconds` is the number of seconds to buffer in case of a backend outage
+    - `requests_per_second` is the average number of requests per seconds.
 
 Example configuration:
 

exporter/kafkaexporter/config.go

@@ -18,11 +18,16 @@ import (
 	"time"
 
 	"go.opentelemetry.io/collector/config/configmodels"
+	"go.opentelemetry.io/collector/exporter/exporterhelper"
 )
 
 // Config defines configuration for Kafka exporter.
 type Config struct {
-	configmodels.ExporterSettings `mapstructure:",squash"`
+	configmodels.ExporterSettings  `mapstructure:",squash"`
+	exporterhelper.TimeoutSettings `mapstructure:",squash"` // squash ensures fields are correctly decoded in embedded struct.
+	exporterhelper.QueueSettings   `mapstructure:"sending_queue"`
+	exporterhelper.RetrySettings   `mapstructure:"retry_on_failure"`
+
 	// The list of kafka brokers (default localhost:9092)
 	Brokers []string `mapstructure:"brokers"`
 	// Kafka protocol version

exporter/kafkaexporter/config_test.go

@@ -17,13 +17,15 @@ package kafkaexporter
 import (
 	"path"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/collector/component/componenttest"
 	"go.opentelemetry.io/collector/config/configmodels"
 	"go.opentelemetry.io/collector/config/configtest"
+	"go.opentelemetry.io/collector/exporter/exporterhelper"
 )
 
 func TestLoadConfig(t *testing.T) {
@@ -42,6 +44,20 @@ func TestLoadConfig(t *testing.T) {
 			NameVal: typeStr,
 			TypeVal: typeStr,
 		},
+		TimeoutSettings: exporterhelper.TimeoutSettings{
+			Timeout: 10 * time.Second,
+		},
+		RetrySettings: exporterhelper.RetrySettings{
+			Enabled:         true,
+			InitialInterval: 10 * time.Second,
+			MaxInterval:     1 * time.Minute,
+			MaxElapsedTime:  10 * time.Minute,
+		},
+		QueueSettings: exporterhelper.QueueSettings{
+			Enabled:      true,
+			NumConsumers: 2,
+			QueueSize:    10,
+		},
 		Topic:   "spans",
 		Brokers: []string{"foo:123", "bar:456"},
 		Metadata: Metadata{

exporter/kafkaexporter/factory.go

@@ -44,13 +44,19 @@ func NewFactory() component.ExporterFactory {
 }
 
 func createDefaultConfig() configmodels.Exporter {
+	// TODO: Enable the queued settings by default.
+	qs := exporterhelper.CreateDefaultQueueSettings()
+	qs.Enabled = false
 	return &Config{
 		ExporterSettings: configmodels.ExporterSettings{
 			TypeVal: typeStr,
 			NameVal: typeStr,
 		},
-		Brokers: []string{defaultBroker},
-		Topic:   defaultTopic,
+		TimeoutSettings: exporterhelper.CreateDefaultTimeoutSettings(),
+		RetrySettings:   exporterhelper.CreateDefaultRetrySettings(),
+		QueueSettings:   qs,
+		Brokers:         []string{defaultBroker},
+		Topic:           defaultTopic,
 		Metadata: Metadata{
 			Full: defaultMetadataFull,
 			Retry: MetadataRetry{
@@ -66,13 +72,18 @@ func createTraceExporter(
 	params component.ExporterCreateParams,
 	cfg configmodels.Exporter,
 ) (component.TraceExporter, error) {
-	c := cfg.(*Config)
-	exp, err := newExporter(*c, params)
+	oCfg := cfg.(*Config)
+	exp, err := newExporter(*oCfg, params)
 	if err != nil {
 		return nil, err
 	}
 	return exporterhelper.NewTraceExporter(
 		cfg,
 		exp.traceDataPusher,
+		// Disable exporterhelper Timeout, because we cannot pass a Context to the Producer,
+		// and will rely on the sarama Producer Timeout logic.
+		exporterhelper.WithTimeout(exporterhelper.TimeoutSettings{Timeout: 0}),
+		exporterhelper.WithRetry(oCfg.RetrySettings),
+		exporterhelper.WithQueue(oCfg.QueueSettings),
 		exporterhelper.WithShutdown(exp.Close))
 }

exporter/kafkaexporter/kafka_exporter.go

@@ -41,6 +41,8 @@ func newExporter(config Config, params component.ExporterCreateParams) (*kafkaPr
 	c.Producer.Return.Errors = true
 	// Wait only the local commit to succeed before responding.
 	c.Producer.RequiredAcks = sarama.WaitForLocal
+	// Because sarama does not accept a Context for every message, set the Timeout here.
+	c.Producer.Timeout = config.Timeout
 	c.Metadata.Full = config.Metadata.Full
 	c.Metadata.Retry.Max = config.Metadata.Retry.Max
 	c.Metadata.Retry.Backoff = config.Metadata.Retry.Backoff

exporter/kafkaexporter/kafka_exporter_test.go

@@ -46,7 +46,9 @@ func TestTraceDataPusher(t *testing.T) {
 		producer:   producer,
 		marshaller: &protoMarshaller{},
 	}
-	defer p.Close(context.Background())
+	t.Cleanup(func() {
+		require.NoError(t, p.Close(context.Background()))
+	})
 	droppedSpans, err := p.traceDataPusher(context.Background(), testdata.GenerateTraceDataTwoSpansSameResource())
 	require.NoError(t, err)
 	assert.Equal(t, 0, droppedSpans)
@@ -63,7 +65,9 @@ func TestTraceDataPusher_err(t *testing.T) {
 		marshaller: &protoMarshaller{},
 		logger:     zap.NewNop(),
 	}
-	defer p.Close(context.Background())
+	t.Cleanup(func() {
+		require.NoError(t, p.Close(context.Background()))
+	})
 	td := testdata.GenerateTraceDataTwoSpansSameResource()
 	droppedSpans, err := p.traceDataPusher(context.Background(), td)
 	assert.EqualError(t, err, expErr.Error())
@@ -78,6 +82,7 @@ func TestTraceDataPusher_marshall_error(t *testing.T) {
 	}
 	td := testdata.GenerateTraceDataTwoSpansSameResource()
 	droppedSpans, err := p.traceDataPusher(context.Background(), td)
+	require.Error(t, err)
 	assert.Contains(t, err.Error(), expErr.Error())
 	assert.Equal(t, td.SpanCount(), droppedSpans)
 }

exporter/kafkaexporter/testdata/config.yaml

@@ -8,6 +8,16 @@ exporters:
       full: false
       retry:
         max: 15
+    timeout: 10s
+    sending_queue:
+      enabled: true
+      num_consumers: 2
+      queue_size: 10
+    retry_on_failure:
+      enabled: true
+      initial_interval: 10s
+      max_interval: 60s
+      max_elapsed_time: 10m
 
 processors:
   exampleprocessor: