Awesome

kafka - Publisher & Consumer for Kafka 0.7.x in Go

Kafka is a distributed publish-subscribe messaging system: (http://kafka.apache.org)

Go language: (http://golang.org/)

For Kafka 0.8.x take a look at https://github.com/Shopify/sarama

Changes

May 2015

fixed bug handling partial message at end of a fetch response when the payload is < 4 bytes
if the the kafka log segment being read is cleaned up, attempt resuming the consumer from the earliest available offset

April 2015

added support for Snappy compression
fixed handling of partial messages at the end of each fetch response
added ProduceFromChannel() method in the publisher, mirroring the ConsumeOnChannel() method in the consumer
changed the quit channel type to empty struct{}, adding ability to stop the consumer on demand without race conditions
reused connection in BatchPublish(), instead of establishing a brand new connection every time.
applied gofmt / golint on the code (renamed Id() to ID() for compliance)
added comments
better distinction between DEBUG and ERROR logs, with info on how to get the consumer unstuck when the max fetch size is too small

April 2013

Merged back from the apache repository & outstanding patches from jira applied

Get up and running

Install go (version 1): For more info see: http://weekly.golang.org/doc/install.html#install

Make sure to set your GOROOT properly (http://golang.org/doc/install.html#environment). Also set your GOPATH appropriately: http://weekly.golang.org/doc/code.html#tmp_13

Build from source:

<code>make kafka</code> Make the tools (publisher & consumer) <code>make tools</code> Start zookeeper, Kafka server For more info on Kafka, see: http://incubator.apache.org/kafka/quickstart.html

Tools

Start a consumer:

<pre><code> $GOPATH/bin/consumer -topic test -consumeforever Consuming Messages : From: localhost:9092, topic: test, partition: 0 ---------------------- </code></pre>

Now the consumer will just poll until a message is received.

Publish a message:

<pre><code> $GOPATH/bin/publisher -topic test -message "Hello World" </code></pre>

The consumer should output message.

API Usage

Publishing

<pre><code> broker := kafka.NewBrokerPublisher("localhost:9092", "mytesttopic", 0) broker.Publish(kafka.NewMessage([]byte("testing 1 2 3"))) </code></pre>

Publishing Compressed Messages

<pre><code> broker := kafka.NewBrokerPublisher("localhost:9092", "mytesttopic", 0) broker.Publish(kafka.NewCompressedMessage([]byte("testing 1 2 3"))) </code></pre>

Consumer

<pre><code> broker := kafka.NewBrokerConsumer("localhost:9092", "mytesttopic", 0, 0, 1048576) broker.Consume(func(msg *kafka.Message) { msg.Print() }) </code></pre>

Or the consumer can use a channel based approach:

<pre><code> broker := kafka.NewBrokerConsumer("localhost:9092", "mytesttopic", 0, 0, 1048576) go broker.ConsumeOnChannel(msgChan, 10, quitChan) </code></pre>

Consuming Offsets

<pre><code> broker := kafka.NewBrokerOffsetConsumer("localhost:9092", "mytesttopic", 0) offsets, err := broker.GetOffsets(-1, 1) </code></pre>

Contact

jeffreydamick (at) gmail (dot) com

http://twitter.com/jeffreydamick

Big thank you to NeuStar for sponsoring this work.