A few months ago, we announced the major release of Apache Kafka 0.9, which added several new features like Security, Kafka Connect, the new Java consumer and also critical bug fixes. Today, I am pleased to announce the availability of the first patch release of the Kafka 0.9 series: the 0.9.0.1 release of Apache Kafka and the corresponding patch release of the Confluent Platform 2.0.1. The 0.9.0.1 release fixes a total of 68 issues, out which 45 are bug fixes and 20 are general improvements.

We recommend all users upgrade to this release by bumping up the version of your Kafka dependencies to 0.9.0.1 (Confluent Platform users: 0.9.0.1-cp1) in your applications and updating the binary installations on server machines.

Here is a quick overview of the notable Kafka-related bug fixes in the release, grouped by the affected functionality. You can review the complete list of issues fixed in the release notes.

New Java consumer

• KAFKA-2978: Topic partition is not sometimes consumed after rebalancing of consumer group
• KAFKA-3179: Kafka consumer delivers message whose offset is earlier than sought offset.
• KAFKA-3157: Mirror maker doesn’t commit offset with new consumer when there is no more messages    
• KAFKA-3170: Default value of fetch_min_bytes in new consumer is 1024 while doc says it is 1

Compatibility

• KAFKA-2695: Handle null string/bytes protocol primitives
• KAFKA-3100: Broker.createBroker should work if json is version > 2, but still compatible
• KAFKA-3012: Avoid reserved.broker.max.id collisions on upgrade

Security

• KAFKA-3198: Ticket Renewal Thread exits prematurely due to inverted comparison
• KAFKA-3152: kafka-acl doesn’t allow space in principal name
• KAFKA-3169: Kafka broker throws OutOfMemory error with invalid SASL packet
• KAFKA-2878: Kafka broker throws OutOfMemory exception with invalid join group request
• KAFKA-3166: Disable SSL client authentication for SASL_SSL security protocol

Performance/memory usage

• KAFKA-3003: The fetch.wait.max.ms is not honored when new log segment rolled for low volume topics
• KAFKA-3159: Kafka consumer 0.9.0.0 client poll is very CPU intensive under certain conditions
• KAFKA-2988: Change default configuration of the log cleaner
• KAFKA-2973: Fix leak of child sensors on remove

Topic deletion

• KAFKA-2937: Topics marked for delete in Zookeeper may become undeletable

Contributors

According to git shortlog, 42 people contributed to this release –

Adam Kunicki, Alex Sherwin, Ashish Singh, Ben Stopford, Binlei Xu, David Jacot, Denise Fernandez, Dmitry Stratiychuk, Dong Lin, Edward Ribeiro, Eno Thereska, Ewen Cheslack-Postava, Geoff Anderson, Grant Henke, Guozhang Wang, Gwen Shapira, Ismael Juma, Jaikiran Pai, James Cheng, Jason Gustafson, Jay Kreps, 
Jesse Anderson, Jiangjie Qin, Jin Xing, Jun Rao, Kim Christensen, Kishore Senji, Luciano Afranllie, Magnus Edenhill, Maksim Logvinenko, Mayuresh Gharat, 
Michael Blume, Piotr Szwed, Praveen Devarao, Rajini Sivaram, Sasaki Toru, Tao Xiao, Tom Graves, Tomasz Nurkiewicz, Vahid Hashemian, Xin Wang, Yifan Ying

How do I get Apache Kafka 0.9.0.1?

The easiest way to get started with or upgrade Kafka is by downloading Confluent Platform. The 2.0.1 release of Confluent Platform is 100% open-source and includes Apache Kafka 0.9.0.1 along with tools that you need to get started with Kafka. Learn more about it by reading the details in the Confluent Platform 2.0.1 documentation or download it to give it a spin.   

Confluent Platform 2.0.1 is backed by our subscription support, and we also offer expert training and technical consulting to help get your organization started.

As always, we are happy to hear your feedback. Please post your questions and suggestions to the public Confluent Platform mailing list.