Version 1.9.0 (2016-05-16)

New Features:

• Add support for custom offset manager retention durations
  (#602).
• Publish low-level mocks to enable testing of third-party producer/consumer
  implementations (#570).
• Declare support for Golang 1.6
  (#611).
• Support for SASL plain-text auth
  (#648).

Improvements:

• Simplified broker locking scheme slightly
  (#604).
• Documentation cleanup
  (#605,
  #621,
  #654).

Bug Fixes:

• Fix race condition shutting down the OffsetManager
  (#658).

Version 1.8.0 (2016-02-01)

New Features:

• Full support for Kafka 0.9:
  • All protocol messages and fields
    (#586,
    #588,
    #590).
  • Verified that TLS support works
    (#581).
  • Fixed the OffsetManager compatibility
    (#585).

Improvements:

• Optimize for fewer system calls when reading from the network
  (#584).
• Automatically retry InvalidMessage errors to match upstream behaviour
  (#589).

Version 1.7.0 (2015-12-11)

New Features:

• Preliminary support for Kafka 0.9
  (#572). This comes with several
  caveats:
  • Protocol-layer support is mostly in place
    (#577), however Kafka 0.9
    renamed some messages and fields, which we did not in order to preserve API
    compatibility.
  • The producer and consumer work against 0.9, but the offset manager does
    not (#573).
  • TLS support may or may not work
    (#581).

Improvements:

• Don't wait for request timeouts on dead brokers, greatly speeding recovery
  when the TCP connection is left hanging
  (#548).
• Refactored part of the producer. The new version provides a much more elegant
  solution to #449. It is also
  slightly more efficient, and much more precise in calculating batch sizes
  when compression is used
  (#549,
  #550,
  #551).

Bug Fixes:

• Fix race condition in consumer test mock
  (#553).

Version 1.6.1 (2015-09-25)

Bug Fixes:

• Fix panic that could occur if a user-supplied message value failed to encode
  (#449).

Version 1.6.0 (2015-09-04)

New Features:

• Implementation of a consumer offset manager using the APIs introduced in
  Kafka 0.8.2. The API is designed mainly for integration into a future
  high-level consumer, not for direct use, although it is possible to use it
  directly.
  (#461).

Improvements:

• CRC32 calculation is much faster on machines with SSE4.2 instructions,
  removing a major hotspot from most profiles
  (#255).

Bug Fixes:

• Make protocol decoding more robust against some malformed packets generated
  by go-fuzz (#523,
  #525) or found in other ways
  (#528).
• Fix a potential race condition panic in the consumer on shutdown
  (#529).

Version 1.5.0 (2015-08-17)

New Features:

• TLS-encrypted network connections are now supported. This feature is subject
  to change when Kafka releases built-in TLS support, but for now this is
  enough to work with TLS-terminating proxies
  (#154).

Improvements:

• The consumer will not block if a single partition is not drained by the user;
  all other partitions will continue to consume normally
  (#485).
• Formatting of error strings has been much improved
  (#495).
• Internal refactoring of the producer for code cleanliness and to enable
  future work (#300).

Bug Fixes:

• Fix a potential deadlock in the consumer on shutdown
  (#475).

Version 1.4.3 (2015-07-21)

Bug Fixes:

• Don't include the partitioner in the producer's "fetch partitions"
  circuit-breaker (#466).
• Don't retry messages until the broker is closed when abandoning a broker in
  the producer (#468).
• Update the import path for snappy-go, it has moved again and the API has
  changed slightly (#486).

Version 1.4.2 (2015-05-27)

Bug Fixes:

• Update the import path for snappy-go, it has moved from google code to github
  (#456).

Version 1.4.1 (2015-05-25)

Improvements:

• Optimizations when decoding snappy messages, thanks to John Potocny
  (#446).

Bug Fixes:

• Fix hypothetical race conditions on producer shutdown
  (#450,
  #451).

Version 1.4.0 (2015-05-01)

New Features:

• The consumer now implements Topics() and Partitions() methods to enable
  users to dynamically choose what topics/partitions to consume without
  instantiating a full client
  (#431).
• The partition-consumer now exposes the high water mark offset value returned
  by the broker via the HighWaterMarkOffset() method (#339).
• Added a kafka-console-consumer tool capable of handling multiple
  partitions, and deprecated the now-obsolete kafka-console-partitionConsumer
  (#439,
  #442).

Improvements:

• The producer's logging during retry scenarios is more consistent, more
  useful, and slightly less verbose
  (#429).
• The client now shuffles its initial list of seed brokers in order to prevent
  thundering herd on the first broker in the list
  (#441).

Bug Fixes:

• The producer now correctly manages its state if retries occur when it is
  shutting down, fixing several instances of confusing behaviour and at least
  one potential deadlock (#419).
• The consumer now handles messages for different partitions asynchronously,
  making it much more resilient to specific user code ordering
  (#325).