go get -u h12.io/kpax


I gave a talk about Kpax at Gopher Meetup Shanghai 2016. See the slides.


The client is built on top of Kafka Wire Protocol (i.e. low-level API). The protocol related types & marshal/unmarshal functions are automatically generated by wipro from the HTML spec).

(-) means to be done.

Sub packages

  • model is an abstraction model for request, response, broker and cluster
  • broker is a lazy, asynchronous and recoverable round tripper that talks to a single Kafka broker
  • cluster is a metadata manager that talks to a Kafka cluster
  • proto contains both low level API and a “middle” level facade
  • producer: fault tolerant high-level producer (batching and partitioning strategy)
  • consumer: fault tolerant high-level consumer (consumer group and offset commit)
  • log: replaceable global logger
  • cmd
    • kpax: command line tool to help with Kafka programming


Compatible with Kafka Server 0.8.2.

Error Handling

  • broker
    • fail fast: timeout returns error immediately
    • release resources carefully
    • reconnect when requested next time
  • client
    • metadata reload lazily (only when a leader/coordinator cannot be found in cache)
    • leader/coordinator should be deleted on error
  • producer
    • fail over to another partition
    • failed partition will be retried again after a period of time
    • partition expand (-)
  • consumer
    • just loop & wait on error
    • partition expand (-)
  • graceful shutdown (-)


  • efficiency
    • batching
    • consumer response
    • consumer request (-)
    • producer (-)
    • decompression
    • snappy
    • gzip (-)
    • compression
    • snappy (-)
    • gzip (-)