Go Kafka Connect Couchbase

Go implementation of the Kafka Connect Couchbase.

Go Kafka Connect Couchbase streams documents from Couchbase Database Change Protocol (DCP) and publishes Kafka events in near real-time.

Features

• Less resource usage and higher throughput(see Benchmarks).
• Custom Kafka key and headers implementation(see Example).
• Sending multiple Kafka events for a DCP event(see Example).
• Handling different DCP events such as expiration, deletion and mutation(see Example).
• Kafka compression support(Gzip, Snappy, Lz4, Zstd).
• Kafka producer acknowledges support(fire-and-forget, wait for the leader, wait for the full ISR).
• Metadata can be saved to Couchbase or Kafka.
• Managing batch configurations such as maximum batch size, batch bytes, batch ticker durations.
• Scale up and down by custom membership algorithms(Couchbase, KubernetesHa, Kubernetes StatefulSet or Static, see examples).
• Easily manageable configurations.

Benchmarks

The benchmark was made with the 1,001,006 Couchbase document, because it is possible to more clearly observe the difference in the batch structure between the two packages. Default configurations for Java Kafka Connect Couchbase used for both connectors.

Package	Time to Process Events	Average CPU Usage(Core)	Average Memory Usage
Go Kafka Connect Couchbase(1.19)	12s	0.383	428MB
Java Kafka Connect Couchbase(JDK11)	19s	1.5	932MB

Example

Basic

package main

import (
	gokafkaconnectcouchbase "github.com/Trendyol/go-kafka-connect-couchbase"
	"github.com/Trendyol/go-kafka-connect-couchbase/couchbase"
	"github.com/Trendyol/go-kafka-connect-couchbase/kafka/message"
)

func mapper(event couchbase.Event) []message.KafkaMessage {
	// return empty if you wish filter the event
	return []message.KafkaMessage{
		{
			Headers: nil,
			Key:     event.Key,
			Value:   event.Value,
		},
	}
}

func main() {
	connector, err := gokafkaconnectcouchbase.NewConnector("./example/config.yml", mapper)
	if err != nil {
		panic(err)
	}

	defer connector.Close()
	connector.Start()
}

Custom log structures can be used with the connector

package main

import (
	gokafkaconnectcouchbase "github.com/Trendyol/go-kafka-connect-couchbase"
	"github.com/Trendyol/go-kafka-connect-couchbase/couchbase"
	"github.com/Trendyol/go-kafka-connect-couchbase/kafka/message"
	"log"
	"os"
)

func mapper(event couchbase.Event) []message.KafkaMessage {
	// return empty if you wish filter the event
	return []message.KafkaMessage{
		{
			Headers: nil,
			Key:     event.Key,
			Value:   event.Value,
		},
	}
}

func main() {
	logger := log.New(os.Stdout, "cb2kafka: ", log.Ldate|log.Ltime|log.Llongfile)

	connector, err := gokafkaconnectcouchbase.NewConnectorWithLoggers("./example/config.yml", mapper, logger, logger)
	if err != nil {
		panic(err)
	}

	defer connector.Close()
	connector.Start()
}

Configuration

Dcp Configuration

Check out on go-dcp-client

Kafka Specific Configuration

Variable	Type	Required	Default	Description
kafka.collectionTopicMapping	map[string]string	yes		Defines which Couchbase collection events will be sent to which topic
kafka.brokers	[]string	yes		Broker ip and port information
kafka.producerBatchSize	integer	no	2000	Maximum message count for batch, if exceed flush will be triggered.
kafka.producerBatchBytes	integer	no	10485760	Maximum size(byte) for batch, if exceed flush will be triggered.
kafka.producerBatchTickerDuration	time.Duration	no	10s	Batch is being flushed automatically at specific time intervals for long waiting messages in batch.
kafka.readTimeout	time.Duration	no	30s	segmentio/kafka-go - Timeout for read operations
kafka.writeTimeout	time.Duration	no	30s	segmentio/kafka-go - Timeout for write operations
kafka.compression	integer	no	0	Compression can be used if message size is large, CPU usage may be affected. 0=None, 1=Gzip, 2=Snappy, 3=Lz4, 4=Zstd
kafka.requiredAcks	integer	no	1	segmentio/kafka-go - Number of acknowledges from partition replicas required before receiving a response to a produce request. 0=fire-and-forget, do not wait for acknowledgements from the, 1=wait for the leader to acknowledge the writes, -1=wait for the full ISR to acknowledge the writes
kafka.secureConnection	bool	no	false	Enable secure Kafka.
kafka.rootCAPath	string	no	*not set	Define root CA path.
kafka.interCAPath	string	no	*not set	Define inter CA path.
kafka.scramUsername	string	no	*not set	Define scram username.
kafka.scramPassword	string	no	*not set	Define scram password.

Exposed metrics

Metric Name	Description	Labels	Value Type
kafka_connector_latency_ms	Time to adding to the batch.	N/A	Gauge
kafka_connector_batch_produce_latency_ms	Time to produce messages in the batch.	N/A	Gauge

For DCP related metrics see also.

Contributing

Go Kafka Connect Couchbase is always open for direct contributions. For more information please check our Contribution Guideline document.

License

Released under the MIT License.