[RATIS-801] Ratis snapshot should consider stateMachine#appliedIndex for triggering snapshot

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 0.5.0
• Assignee: Unassigned
• Reporter: Shashikant Banerjee
• Created: 23/Jan/20 09:30
• Updated: 09/Jan/24 22:23
• Resolved: 09/Jan/24 22:23

Description

Currently, while triggering snapshot, snapshotUpdater#appliedIndex is taken into account to decide whether it has exceeded the snapshot threshold from the last snapshotIndex. This may lead to creating more snapshots than usual as stateMachineUpdater#appliedIndex is updated as soon as the applyTransaction call happens. Ideally, Ratis snapshot should not be triggered taking stateMachine's applied index into account.

Issue Links

• duplicates: RATIS-877 StateMachineUpdater#takeSnapshot should check stateMachine lastAppliedIndex
• duplicates: RATIS-1548 use stateMachine#lastAppliedIndex instead of stateMachinUpdater#lastAppliedIndex when checking snapshot should be taken