[IGNITE-13798] Prototype Raft implementation port to a separate zero-dependency Ignite module

• Type: New Feature
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Labels: iep-61 ignite-3
• Ignite Flags: Docs Required, Release Notes Required
• Assignee: Alexey Goncharuk
• Reporter: Alexey Goncharuk
• Created: 02/Dec/20 13:20
• Updated: 02/Dec/20 13:20

Description

We need to check whether it is reasonable and feasible to port the etcd Raft implementation [1] to Java, maintaining the same API interaction model:

• Raft instance is a single-threaded state machine with methods to accept messages, return progress to be processed by a raft client, and tick callback
• Raft instance does not actively send messages, not does it actively write to persistent log or the state machine

The implementation should demonstrate how the module will be used with omitted components: Raft Log, State Machine, Messaging, Timer.

The implementation must cover:

• Ability to provide leader/follower callbacks
• Ability to read linearizable and relaxed commit indexes

The implementation may cover:

• Replication group reconfiguration

The implementation prototype does not cover:

• Multi-raft groups
• Asynchronous state machine mutation