[RATIS-1643] Add heartbeat broadcast mechanism for leader readIndex

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0, 2.5.0
• Component/s: conf, gRPC, Linearizable Read, raft-group
• Assignee: Song Ziyang
• Reporter: Song Ziyang
• Created: 28/Jul/22 05:39
• Updated: 04/Aug/23 18:45
• Resolved: 30/Aug/22 20:38

Description

Add the heartbeat broadcast mechanism in LeaderStateImpl:

When requested for readIndex, leader should broadcast a round of heartbeats to all followers. If the majority successfully acknowledges, then the leadership is confirmed and the readIndex can be safely returned.

Issue Links

• links to: GitHub Pull Request #730