Add ReadIndexAsync() to RaftNode that confirms leader quorum by sending
heartbeat RPCs before returning CommitIndex, avoiding log growth for reads.
Add RaftReadIndexTests.cs with 13 tests covering normal path, non-leader
rejection, partitioned leader timeout, single-node fast path, log stability,
and peer LastContact refresh after heartbeat round.
Add RandomizedElectionTimeout() method to RaftNode returning TimeSpan in
[ElectionTimeoutMinMs, ElectionTimeoutMaxMs) using TotalMilliseconds (not
.Milliseconds component) to prevent synchronized elections after partitions.
Make Random injectable for deterministic testing. Fix SendHeartbeatAsync stub
in NatsRaftTransport and test-local transport implementations to satisfy the
IRaftTransport interface added in Gap 8.7.
Add HasQuorum() to RaftNode that counts peers with LastContact within
2 × ElectionTimeoutMaxMs and returns true only when self + current peers
reaches majority. ProposeAsync now throws InvalidOperationException with
"no quorum" when HasQuorum() returns false, preventing a partitioned
leader from diverging the log. Add 14 tests in RaftQuorumCheckTests.cs
covering single-node, 3-node, 5-node, boundary window, and heartbeat
restore scenarios. Update RaftHealthTests.LastContact_updates_on_successful_replication
to avoid triggering the new quorum guard.
- Add RaftTimeoutNowWire: 16-byte wire type [8:term][8:leaderId] with
Encode/Decode roundtrip, matching Go's sendTimeoutNow wire layout
- Add TimeoutNow(group) subject "$NRG.TN.{group}" to RaftSubjects
- Add SendTimeoutNowAsync to IRaftTransport; implement in both
InMemoryRaftTransport (synchronous delivery) and NatsRaftTransport
(publishes to $NRG.TN.{group})
- Add TransferLeadershipAsync(targetId, ct) to RaftNode: leader sends
TimeoutNow RPC, blocks proposals via _transferInProgress flag, polls
until target becomes leader or 2x election timeout elapses
- Add ReceiveTimeoutNow(term) to RaftNode: target immediately starts
election bypassing pre-vote, updates term if sender's term is higher
- Block ProposeAsync with InvalidOperationException during transfer
- 15 tests in RaftLeadershipTransferTests covering wire roundtrip,
ReceiveTimeoutNow behaviour, proposal blocking, target leadership,
timeout on unreachable peer, and transfer flag lifecycle
- Add SnapshotChunkEnumerator: IEnumerable<byte[]> that splits snapshot data
into fixed-size chunks (default 65536 bytes) and computes CRC32 over the
full payload for integrity validation during streaming transfer
- Add RaftInstallSnapshotChunkWire: 24-byte header + variable data wire type
encoding [snapshotIndex:8][snapshotTerm:4][chunkIndex:4][totalChunks:4][crc32:4][data:N]
- Extend InstallSnapshotFromChunksAsync with optional expectedCrc32 parameter;
validates assembled data against CRC32 before applying snapshot state, throwing
InvalidDataException on mismatch to prevent corrupt state installation
- Fix stub IRaftTransport implementations in test files missing SendTimeoutNowAsync
- Fix incorrect role assertion in RaftLeadershipTransferTests (single-node quorum = 1)
- 15 new tests in RaftSnapshotStreamingTests covering enumeration, reassembly,
CRC correctness, validation success/failure, and wire format roundtrip
Adds BeginJointConsensus, CommitJointConsensus, and CalculateJointQuorum to
RaftNode per Raft paper Section 4. During a joint configuration transition
quorum requires majority from BOTH Cold and Cnew; CommitJointConsensus
finalizes Cnew as the sole active configuration. The existing single-phase
ProposeAddPeerAsync/ProposeRemovePeerAsync are unchanged. Includes 16 new
tests covering flag behaviour, quorum boundaries, idempotent commit, and
backward-compatibility with the existing membership API.
- SyncAsync: remove redundant FlushAsync, use single Flush(flushToDisk:true)
- ComputeCrc: use incremental Crc32.Append to avoid contiguous buffer heap allocation
- Load: cast pos+length to long to guard against int overflow in bounds check
- AppendAsync: delegate to WriteEntryTo (DRY — eliminates duplicated record-building logic)
- Load: extract ParseEntries static helper to eliminate goto pattern with early returns
- Entries: change return type from IEnumerable to IReadOnlyList for index access and Count property
- RaftNode.PersistAsync: remove redundant term.txt write (meta.json now owns term+votedFor)
- RaftWalTests: tighten ShouldBeGreaterThanOrEqualTo(1) -> ShouldBe(1) in truncation/CRC tests;
use .Count property directly on IReadOnlyList instead of .Count() LINQ extension
Implements a binary write-ahead log (RaftWal) for durable RAFT entry
storage, replacing in-memory-only semantics. The WAL uses a magic header
("NWAL" + version), length-prefixed records with per-record CRC32
integrity checking, and CompactAsync with atomic temp-file rename.
Load() tolerates truncated or corrupt tail records for crash safety.
Also fixes RaftNode to persist and reload TermState.VotedFor via a
meta.json file alongside term.txt, ensuring vote durability across
restarts. Falls back gracefully to legacy term.txt when meta.json is
absent.
6 new tests in RaftWalTests: persist/recover, compact, truncation
tolerance, VotedFor round-trip, empty WAL, and CRC corruption.
All 458 Raft tests pass.
- ProposeAddPeerAsync/ProposeRemovePeerAsync: single-change-at-a-time membership
changes through RAFT consensus (Go ref: raft.go:961-1019)
- RaftLog.Compact: removes entries up to given index for log compaction
- CreateSnapshotCheckpointAsync: creates snapshot and compacts log in one operation
- DrainAndReplaySnapshotAsync: drains commit queue, installs snapshot, resets indices
- Pre-vote protocol skipped (Go NATS doesn't implement it either)
- 23 new tests in RaftMembershipAndSnapshotTests
- CommitQueue<T>: channel-based queue for committed entries awaiting state machine application
- RaftPeerState: tracks replication and health state (nextIndex, matchIndex, lastContact)
- RaftNode: CommitIndex/ProcessedIndex tracking, election timer with randomized 150-300ms interval,
peer state integration with heartbeat and replication updates
- 52 new tests across RaftApplyQueueTests, RaftElectionTimerTests, RaftHealthTests
Implements RaftSubjects static class with Go's $NRG.* subject constants
and NatsRaftTransport which routes RAFT RPCs over those subjects using
RaftAppendEntryWire / RaftVoteRequestWire encoding. 43 tests cover all
subject patterns, wire encoding fidelity, and transport construction.
