Status
Current state: Draft
Discussion thread: TBD
JIRA: TBD
Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).
Motivation
KIP-595 ships a Kafkaesque Raft algorithm to serve as the foundation of metadata quorum. We migrated and customized the Raft protocol to fit in metadata replication need, but the exploration does not end with just the basic replication and leader election. There are more standard features described in the Raft literature, which are very useful in general production system as well as in Kafka context. In this follow-up KIP, we would like to ship two major features, the pre-vote and non-leader linearizable read.
Proposed Changes
Pre-vote
In the context of
Public Interfaces
Briefly list any new interfaces that will be introduced as part of this proposal or any existing interfaces that will be removed or changed. The purpose of this section is to concisely call out the public contract that will come along with this feature.
A public interface is any change to the following:
Binary log format
The network protocol and api behavior
Any class in the public packages under clientsConfiguration, especially client configuration
org/apache/kafka/common/serialization
org/apache/kafka/common
org/apache/kafka/common/errors
org/apache/kafka/clients/producer
org/apache/kafka/clients/consumer (eventually, once stable)
Monitoring
Command line tools and arguments
- Anything else that will likely break existing users in some way when they upgrade
Compatibility, Deprecation, and Migration Plan
- What impact (if any) will there be on existing users?
- If we are changing behavior how will we phase out the older behavior?
- If we need special migration tools, describe them here.
- When will we remove the existing behavior?
Rejected Alternatives
If there are alternative ways of accomplishing the same thing, what were they? The purpose of this section is to motivate why the design is the way it is and not some other way.