[KAFKA-1050] Support for "no data loss" mode

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Assignee: Neha Narkhede
• Reporter: Justin SB
• Created: 08/Sep/13 00:52
• Updated: 07/Feb/15 23:17
• Resolved: 07/Feb/15 23:17

Description

I'd love to use Apache Kafka, but for my application data loss is not acceptable. Even at the expense of availability (i.e. I need C not A in CAP).

I think there are two things that I need to change to get a quorum model:

1) Make sure I set request.required.acks to 2 (for a 3 node cluster) or 3 (for a 5 node cluster) on every request, so that I can only write if a quorum is active.

2) Prevent the behaviour where a non-ISR can become the leader if all ISRs die. I think this is as easy as tweaking core/src/main/scala/kafka/controller/PartitionLeaderSelector.scala, essentially to throw an exception around line 64 in the "data loss" case.

I haven't yet implemented / tested this. I'd love to get some input from the Kafka-experts on whether my plan is:
(a) correct - will this work?
(b) complete - have I missed any cases?
(c) recommended - is this a terrible idea

Thanks for any pointers!