[receiver/kafkaexporter]: allow tunable fetch sizes

This commit adds the ability to tune the minimum, default and maximum fetch sizes for Kafka in the OpenTelemetry configuration file.

Author: Cody Kaczynski

receiver/kafkareceiver/README.md

@@ -45,6 +45,9 @@ The following settings can be optionally configured:
 - `initial_offset` (default = latest): The initial offset to use if no offset was previously committed. Must be `latest` or `earliest`.
 - `session_timeout` (default = `10s`): The request timeout for detecting client failures when using Kafka’s group management facilities.
 - `heartbeat_interval` (default = `3s`): The expected time between heartbeats to the consumer coordinator when using Kafka’s group management facilities.
+- `min_fetch_size` (default = `1`): The minimum number of message bytes to fetch in a request, defaults to 1 byte.
+- `default_fetch_size` (default = `1048576`): The default number of message bytes to fetch in a request, defaults to 1MB.
+- `max_fetch_size` (default = `0`): The maximum number of message bytes to fetch in a request, defaults to unlimited.
 - `auth`
   - `plain_text`
     - `username`: The username to use.

receiver/kafkareceiver/config.go

@@ -78,6 +78,13 @@ type Config struct {
 
 	// Extract headers from kafka records
 	HeaderExtraction HeaderExtraction `mapstructure:"header_extraction"`
+
+	// The minimum bytes per fetch from Kafka (default "1")
+	MinFetchSize int32 `mapstructure:"min_fetch_size"`
+	// The default bytes per fetch from Kafka (default "1048576")
+	DefaultFetchSize int32 `mapstructure:"default_fetch_size"`
+	// The maximum bytes per fetch from Kafka (default "0")
+	MaxFetchSize int32 `mapstructure:"max_fetch_size"`
 }
 
 const (

receiver/kafkareceiver/config_test.go

@@ -62,6 +62,9 @@ func TestLoadConfig(t *testing.T) {
 					Enable:   true,
 					Interval: 1 * time.Second,
 				},
+				MinFetchSize:     1,
+				DefaultFetchSize: 1048576,
+				MaxFetchSize:     0,
 			},
 		},
 		{
@@ -96,6 +99,9 @@ func TestLoadConfig(t *testing.T) {
 					Enable:   true,
 					Interval: 1 * time.Second,
 				},
+				MinFetchSize:     1,
+				DefaultFetchSize: 1048576,
+				MaxFetchSize:     0,
 			},
 		},
 	}

receiver/kafkareceiver/factory.go

@@ -40,6 +40,13 @@ const (
 	defaultAutoCommitEnable = true
 	// default from sarama.NewConfig()
 	defaultAutoCommitInterval = 1 * time.Second
+
+	// default from sarama.NewConfig()
+	defaultMinFetchSize = 1
+	// default from sarama.NewConfig()
+	defaultDefaultFetchSize = 1048576
+	// default from sarama.NewConfig()
+	defaultMaxFetchSize = 0
 )
 
 var errUnrecognizedEncoding = fmt.Errorf("unrecognized encoding")
@@ -120,6 +127,9 @@ func createDefaultConfig() component.Config {
 		HeaderExtraction: HeaderExtraction{
 			ExtractHeaders: false,
 		},
+		MinFetchSize:     defaultMinFetchSize,
+		DefaultFetchSize: defaultDefaultFetchSize,
+		MaxFetchSize:     defaultMaxFetchSize,
 	}
 }
 

receiver/kafkareceiver/factory_test.go

@@ -28,6 +28,9 @@ func TestCreateDefaultConfig(t *testing.T) {
 	assert.Equal(t, defaultInitialOffset, cfg.InitialOffset)
 	assert.Equal(t, defaultSessionTimeout, cfg.SessionTimeout)
 	assert.Equal(t, defaultHeartbeatInterval, cfg.HeartbeatInterval)
+	assert.Equal(t, defaultMinFetchSize, cfg.MinFetchSize)
+	assert.Equal(t, defaultDefaultFetchSize, cfg.DefaultFetchSize)
+	assert.Equal(t, defaultMaxFetchSize, cfg.MaxFetchSize)
 }
 
 func TestCreateTracesReceiver(t *testing.T) {

receiver/kafkareceiver/kafka_receiver.go

@@ -48,6 +48,9 @@ type kafkaTracesConsumer struct {
 	messageMarking    MessageMarking
 	headerExtraction  bool
 	headers           []string
+	minFetchSize      int32
+	defaultFetchSize  int32
+	maxFetchSize      int32
 }
 
 // kafkaMetricsConsumer uses sarama to consume and handle messages from kafka.
@@ -66,6 +69,9 @@ type kafkaMetricsConsumer struct {
 	messageMarking    MessageMarking
 	headerExtraction  bool
 	headers           []string
+	minFetchSize      int32
+	defaultFetchSize  int32
+	maxFetchSize      int32
 }
 
 // kafkaLogsConsumer uses sarama to consume and handle messages from kafka.
@@ -84,6 +90,9 @@ type kafkaLogsConsumer struct {
 	messageMarking    MessageMarking
 	headerExtraction  bool
 	headers           []string
+	minFetchSize      int32
+	defaultFetchSize  int32
+	maxFetchSize      int32
 }
 
 var _ receiver.Traces = (*kafkaTracesConsumer)(nil)
@@ -111,6 +120,9 @@ func newTracesReceiver(config Config, set receiver.Settings, unmarshaler TracesU
 		headerExtraction:  config.HeaderExtraction.ExtractHeaders,
 		headers:           config.HeaderExtraction.Headers,
 		telemetryBuilder:  telemetryBuilder,
+		minFetchSize:      config.MinFetchSize,
+		defaultFetchSize:  config.DefaultFetchSize,
+		maxFetchSize:      config.MaxFetchSize,
 	}, nil
 }
 
@@ -124,6 +136,9 @@ func createKafkaClient(config Config) (sarama.ConsumerGroup, error) {
 	saramaConfig.Consumer.Offsets.AutoCommit.Interval = config.AutoCommit.Interval
 	saramaConfig.Consumer.Group.Session.Timeout = config.SessionTimeout
 	saramaConfig.Consumer.Group.Heartbeat.Interval = config.HeartbeatInterval
+	saramaConfig.Consumer.Fetch.Min = config.MinFetchSize
+	saramaConfig.Consumer.Fetch.Default = config.DefaultFetchSize
+	saramaConfig.Consumer.Fetch.Max = config.MaxFetchSize
 
 	var err error
 	if saramaConfig.Consumer.Offsets.Initial, err = toSaramaInitialOffset(config.InitialOffset); err != nil {
@@ -234,6 +249,9 @@ func newMetricsReceiver(config Config, set receiver.Settings, unmarshaler Metric
 		headerExtraction:  config.HeaderExtraction.ExtractHeaders,
 		headers:           config.HeaderExtraction.Headers,
 		telemetryBuilder:  telemetryBuilder,
+		minFetchSize:      config.MinFetchSize,
+		defaultFetchSize:  config.DefaultFetchSize,
+		maxFetchSize:      config.MaxFetchSize,
 	}, nil
 }
 
@@ -328,6 +346,9 @@ func newLogsReceiver(config Config, set receiver.Settings, unmarshaler LogsUnmar
 		headerExtraction:  config.HeaderExtraction.ExtractHeaders,
 		headers:           config.HeaderExtraction.Headers,
 		telemetryBuilder:  telemetryBuilder,
+		minFetchSize:      config.MinFetchSize,
+		defaultFetchSize:  config.DefaultFetchSize,
+		maxFetchSize:      config.MaxFetchSize,
 	}, nil
 }