Interface ConsumerGroupHandler

consumer_group.go:1234–1248

-------------------------------------------------------------------- ConsumerGroupHandler instances are used to handle individual topic/partition claims. It also provides hooks for your consumer group session life-cycle and allow you to trigger logic before or after the consume loop(s). PLEASE NOTE

// PLEASE NOTE that handlers are likely be called from several goroutines concurrently,
// ensure that all state is safely protected against race conditions.
type ConsumerGroupHandler interface {
	// Setup is run at the beginning of a new session, before ConsumeClaim.
	Setup(ConsumerGroupSession) error

	// Cleanup is run at the end of a session, once all ConsumeClaim goroutines have exited
	// but before the offsets are committed for the very last time.
	Cleanup(ConsumerGroupSession) error

	// ConsumeClaim must start a consumer loop of ConsumerGroupClaim's Messages().
	// Once the Messages() channel is closed, the Handler must finish its processing
	// loop and exit. Handlers should also return when ConsumerGroupSession.Context()
	// is done; Messages() alone can block while the partition consumer is retrying
	// (e.g. after a broker disconnect). See examples/consumergroup.
	ConsumeClaim(ConsumerGroupSession, ConsumerGroupClaim) error
}

// ConsumerGroupClaim processes Kafka messages from a given topic and partition within a consumer group.
type ConsumerGroupClaim interface {