...

1. Committed voter present in voters or observers
   • If committed voter also exists in the voters or observer set, its ReplicaState is identical to the corresponding entry in that set.
   • All field within the ReplicaState are fully available.
2. Committed voter absent from voters or observers 
   • If a committed voter
   does
   • is not
   exist
   • present in either the voters or observers set, the following fields in its ReplicaState are assigned sentinel values:

     • endLogOffset = -1

     • lastFetchTimestamp = -1

     • lastCaughtUpTimestamp = -1

   • These fields
   above are help users to know
   • provide information about the current voter set
   information and its not help user to understand committed voter status so we can allow them to be sentinel value
   • , but they do not reflect the committed voter status. Therefore, it is acceptable for them to take sentinel values.

Benefit

This mechanism strengthens the Raft membership model by:

• Making committed membership explicit.

• Providing a consistent interface for tooling and client introspection.

• Improving the overall transparency and debuggability of the cluster state.

• Reducing performance overhead by avoiding disk operations, since all required voter state and high watermark data are memory-resident.

Compatibility, Deprecation, and Migration Plan

...

Unit test and integration test will be added.

Rejected Alternatives

• A new field, state, can be introduced within the ReplicaState structure to explicitly track the committed status of the voter.