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