ConsumerGroup in Go
ConsumerGroup is responsible for dividing up processing of topics and partitions over a collection of processes (the members of the consumer group).
package main
import (
"context"
"fmt"
)
type exampleConsumerGroupHandler struct{}
func (exampleConsumerGroupHandler) Setup(_ ConsumerGroupSession) error { return nil }
func (exampleConsumerGroupHandler) Cleanup(_ ConsumerGroupSession) error { return nil }
func (h exampleConsumerGroupHandler) ConsumeClaim(sess ConsumerGroupSession, claim ConsumerGroupClaim) error {
for msg := range claim.Messages() {
fmt.Printf("Message topic:%q partition:%d offset:%d\n", msg.Topic, msg.Partition, msg.Offset)
sess.MarkMessage(msg, "")
}
return nil
}
func main() {
// Init config, specify appropriate version
config := NewConfig()
config.Version = V1_0_0_0
config.Consumer.Return.Errors = true
// Start with a client
client, err := NewClient([]string{"localhost:9092"}, config)
if err != nil {
panic(err)
}
defer func() { _ = client.Close() }()
// Start a new consumer group
group, err := NewConsumerGroupFromClient("my-group", client)
if err != nil {
panic(err)
}
defer func() { _ = group.Close() }()
// Track errors
go func() {
for err := range group.Errors() {
fmt.Println("ERROR", err)
}
}()
// Iterate over consumer sessions.
ctx := context.Background()
for {
topics := []string{"my-topic"}
handler := exampleConsumerGroupHandler{}
err := group.Consume(ctx, topics, handler)
if err != nil {
panic(err)
}
}
}