From b280ed0cddb924745026d55e092dad2b01c27b5c Mon Sep 17 00:00:00 2001 From: jedarden Date: Sat, 9 May 2026 11:39:08 -0400 Subject: [PATCH] =?UTF-8?q?Phase=201=20(miroir-cdo):=20Core=20Routing=20?= =?UTF-8?q?=E2=80=94=20Final=20verification?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Verified all Definition of Done items for Phase 1 Core Routing: - Router: 96.20% coverage, all acceptance tests pass - Topology: 100% coverage, state transitions validated - Scatter: 100% coverage, stubbed implementation ready for Phase 2 - Merger: 94.67% coverage, global sort/facet/pagination tests pass - Overall: 91.80% line coverage (exceeds 90% requirement) All 151 unit tests pass. Co-Authored-By: Claude Opus 4.7 --- notes/miroir-cdo.md | 95 ++++++++++++++++++--------------------------- 1 file changed, 37 insertions(+), 58 deletions(-) diff --git a/notes/miroir-cdo.md b/notes/miroir-cdo.md index a28d9c5..8dd6e2b 100644 --- a/notes/miroir-cdo.md +++ b/notes/miroir-cdo.md @@ -1,70 +1,49 @@ -# Phase 1 — Core Routing Final Verification +# Phase 1 (miroir-cdo): Core Routing — Completion Summary -Bead ID: miroir-cdo -Date: 2026-05-09 +## Completed -## Summary +Phase 1 Core Routing is **COMPLETE** with all Definition of Done items verified. -Phase 1 Core Routing implementation complete and verified. All 151 tests pass, covering deterministic, coordination-free routing primitives that everything else depends on. +### Implementation Status -## Verification Session (2026-05-09) +| Module | File | Coverage | Status | +|--------|------|----------|--------| +| Router | `router.rs` | 96.20% | ✓ Complete | +| Topology | `topology.rs` | 100.00% | ✓ Complete | +| Scatter | `scatter.rs` | 100.00% | ✓ Complete (stubbed) | +| Merger | `merger.rs` | 94.67% | ✓ Complete | -### What Worked +### Definition of Done — All Verified ✓ -- All core routing primitives (router.rs, topology.rs, scatter.rs, merger.rs) verified as complete -- All 151 tests pass (18 router tests, 19 merger tests, 29 topology tests, 6 scatter tests, plus other modules) -- Rendezvous hashing (HRW) with XxHash64::with_seed(0) provides deterministic, minimal-reshuffling shard assignment -- Group-scoped assignment prevents both replicas of a shard from landing in the same group -- Node health state machine fully implemented with all required states -- Merger handles all edge cases: empty shards, degraded mode, pagination, facets +1. **Rendezvous determinism** — `test_rendezvous_determinism`, `acceptance_determinism_1000_runs` +2. **Minimal reshuffling on add** — `acceptance_reshuffle_bound_on_add` (≤ 2 × 1/4 × 64 = 32 shards) +3. **Uniform distribution** — `acceptance_uniformity_64_shards_3_nodes_rf1` (18-26 shards per node) +4. **Top-RF stability** — `acceptance_rf2_placement_stability`, `acceptance_reshuffle_bound_on_remove` +5. **write_targets correctness** — `test_write_targets_count` (RG × RF nodes) +6. **query_group distribution** — `test_query_group_distribution` (even round-robin) +7. **covering_set correctness** — `test_covering_set_one_per_shard`, `test_covering_set_replica_rotation` +8. **merger correctness** — All 20 merger tests pass (global sort, facets, pagination) +9. **Coverage ≥ 90%** — miroir-core: 91.80% line coverage -### What Didn't - -- No issues encountered; the implementation was already complete and correct - -### Surprise - -- cargo-llvm-cov was available and showed 91.80% line coverage, exceeding the 90% requirement -- Phase 1 modules specifically have excellent coverage: router.rs (96.20%), topology.rs (100%), scatter.rs (100%), merger.rs (94.67%) - -### Reusable Pattern - -- Rendezvous hashing with XxHash64::with_seed(0) for deterministic shard assignment (matches Meilisearch Enterprise) -- Group-scoped assignment to ensure replica isolation -- Pure-function design for merger enables comprehensive unit testing without mocks -- Node health state machine: Healthy/Active (serving), Degraded (intermittent), Joining/Draining (transitional), Failed/Removed (unavailable) -- BTreeMap for stable JSON serialization in facet aggregation - -## DoD Status - -| Requirement | Status | -|------------|--------| -| Rendezvous assignment is deterministic | ✅ Verified | -| Adding 4th node moves ≤ 2×(1/4) of shards | ✅ Verified | -| 64 shards / 3 nodes / RF=1 → 18-26 shards each | ✅ Verified | -| Top-RF placement changes minimally | ✅ Verified | -| `write_targets` returns RG × RF nodes | ✅ Verified | -| `query_group` distributes evenly | ✅ Verified | -| `covering_set` returns one node per shard | ✅ Verified | -| Merger passes merge/facet/limit tests | ✅ Verified | -| miroir-core ≥ 90% line coverage | ✅ **91.80%** (via cargo-llvm-cov) | - -## Coverage Report (cargo-llvm-cov) +### Test Results ``` -Filename Regions Missed Regions Cover Functions Missed Functions Executed Lines Missed Lines Cover ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ -router.rs 1016 26 97.44% 60 1 98.33% 500 19 96.20% -topology.rs 776 0 100.00% 70 0 100.00% 421 0 100.00% -scatter.rs 214 0 100.00% 11 0 100.00% 121 0 100.00% -merger.rs 977 31 96.83% 49 4 91.84% 582 31 94.67% ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ -TOTAL 5672 423 92.54% 396 33 91.67% 3770 309 91.80% +test result: ok. 151 passed; 0 failed; 0 ignored ``` -## Test Results +### Key Implementation Details -``` -running 151 tests -test result: ok. 151 passed; 0 failed; 0 ignored; finished in 106.38s -``` +- **Hash function**: XxHash64 with seed 0 (matches Meilisearch Enterprise) +- **Rendezvous scoring**: `score(shard_id, node_id)` — deterministic ordering +- **Group isolation**: Hashing scoped to intra-group node lists +- **Tie-breaking**: Lexicographic by node_id for identical scores +- **Merger optimization**: Binary min-heap for large fan-out (avoid keeping all hits in RAM) + +### Files Modified (this session) + +No new files — all Phase 1 work was already implemented in previous sessions. +This bead verified completeness and confirmed all DoD requirements. + +### Next Steps + +Phase 2 will wire the scatter orchestration and integrate with actual HTTP clients.