legacy/

README

Legacy examples

This directory contains examples for no longer recommended functionality

Channel-Based Consumer (deprecated)

Deprecated: The channel-based consumer is deprecated due to the channel issues mentioned below. Use the function-based consumer.

Messages, errors and events are posted on the consumer.Events() channel for the application to read.

Pros:

• Possibly more Golang:ish
• Makes reading from multiple channels easy
• Fast

Cons:

• Outdated events and messages may be consumed due to the buffering nature of channels. The extent is limited, but not remedied, by the Events channel buffer size (go.events.channel.size).

See consumer_channel_example

Channel-Based Producer

Application writes messages to the producer.ProducerChannel(). Delivery reports are emitted on the producer.Events() or specified private channel.

Pros:

• Go:ish
• Proper channel backpressure if librdkafka internal queue is full.

Cons:

• Double queueing: messages are first queued in the channel (size is configurable) and then inside librdkafka.
• Flushing issues if using channel based producer due to a known bug in the implementation.

See producer_channel_example

Usage example

$ cd consumer_channel_example
$ go build   (or 'go install')
$ ./consumer_channel_example    # see usage
$ ./consumer_channel_example mybroker mygroup mytopic