dimgigov
16ec8b5dc4
- Add raft-cluster-status overview (C3a/C3b/post-C3b shipped on main) - Mark C3a/C3b design+plans done; refresh operator docs en/bg - CHANGELOG 1.2.0 Raft section; README cluster example and status line - monitoring.md health/metrics match real HTTP port+440 and raft series
1.2 KiB
1.2 KiB
Networked Raft Bootstrap (C3a) — Design
Date: 2026-07-30
Status: Done (merged to main). See also 2026-07-30-raft-cluster-status.md.
Problem
Raft in BaraDB was half-wired for real networking. core/raft.nim already had
a TCP transport, but production never populated peerAddrs, never ran an
election timer, did not reset timers on AppendEntries, skipped state
persistence, and used unsafe partial frame reads.
Goal
A 3-node BaraDB cluster elects a leader over TCP, maintains it with heartbeats,
and re-elects after the leader is killed — verified with real processes
(tests/raft_e2e_test.nim).
Delivered
| Item | Implementation |
|---|---|
| Peer addresses | BARADB_RAFT_PEERS=id@host:port → raftPeerAddrs |
| Election timer | timerLoop inside RaftNetwork.run |
| Heartbeat reset | processMessage resets timer on AppendEntries with valid term |
| State persistence | dataDir → raft_state.bin |
| Partial reads | recvExact frame reassembly |
| E2E | tests/raft_e2e_test.nim (election + failover) |
Non-goals (handled later)
SQL writes (C3b), DDL/forward/compact/metrics (post-C3b / C3c-lite) — all shipped; see cluster status doc. Still open: membership, InstallSnapshot SM payload, multi-DB raft.