Commit graph

13 commits

Author SHA1 Message Date
jedarden
096b43ccab P12.OP4: Implement dfs_query_then_fetch for cross-shard comparability
Implements the Elasticsearch dfs_query_then_fetch pattern as a pre-query
phase in Miroir to resolve cross-shard score comparability issues caused
by differing local IDF values across shards with skewed document distributions.

Core changes:
- scatter.rs: New PreflightRequest/PreflightResponse types, GlobalIdf
  aggregation, execute_preflight and dfs_query_then_fetch_search functions
- Proxy client: preflight_node implementation for term-frequency gathering
- Search routes: Integration of DFS preflight before main search phase
- Integration test: dfs_skewed_corpus.rs with 10 tests covering aggregation
  and serialization
- Benchmark: dfs_preflight_bench.rs measuring preflight overhead

Validation results (1,443 queries, 10-shard skewed corpus):
- Average Kendall tau: 0.9815 (95% CI: [0.9809, 0.9821])
- Min tau: 0.9523 (zero queries below 0.95 threshold)
- Per-type: common-term +0.84, single-term +0.11, filtered +0.11

The preflight phase adds one network round-trip before the search phase,
with requests parallelized across shards. Estimated overhead: +1-2 RTTs.

Resolves bead miroir-yio: Global-IDF preflight implementation.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-19 03:43:10 -04:00
jedarden
b201f0ff58 P12.OP4: Finalize score normalization validation — RRF τ=0.14, score τ=0.79
Research complete: both score-based and RRF merge fail 0.95 threshold.
Updated research doc with full RRF validation results and confidence intervals.
Added benchmark result reports and helper tests. Follow-up bead miroir-n6v
created for global-IDF preflight (dfs_query_then_fetch pattern).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-19 02:40:54 -04:00
jedarden
9ce1b36206 P12.OP4: Add confidence intervals to score comparability benchmark
Research doc updated with precise 95% CIs per query type. compare.py
now computes and reports confidence intervals. Kendall τ = 0.79
(95% CI [0.7873, 0.8006]) confirms raw score merging is not viable;
RRF already implemented in merger.rs as mitigation. Follow-up bead
created (miroir-zfo) for RRF quality validation.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-19 00:07:42 -04:00
jedarden
72f9a197b5 P12.OP4: Score normalization at scale — research & benchmark infrastructure
Completed Plan §15 Open Problem #4 research on cross-shard score comparability.

## Key Finding
Average Kendall tau: 0.79 vs. 0.95 threshold — FAIL

Cross-shard score comparability is a significant issue:
- Common-term queries: τ = 0.15 (catastrophic)
- Local IDF statistics cause score inflation on small shards
- Documents from 10-doc shards outrank 93K-doc shard results

## Recommendation
Implement Reciprocal Rank Fusion (RRF) for result merging.
Follow-up bead: miroir-nsu

## Artifacts Added
- Benchmark infrastructure: tests/benches/score-comparability/
  - Corpus generator with extreme shard skew (100× variance)
  - Query generator (10K random queries across 5 types)
  - BM25-based simulation with global vs local IDF
  - Kendall tau comparison tool
  - Full experimental results (τ = 0.79 ± 0.01, 95% CI)
- Research writeup: docs/research/score-normalization-at-scale.md

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-18 23:58:08 -04:00
jedarden
c30d867d27 P0.7: Update plan with chaos-test results, sync beads
Verified CI smoke pipeline runs end-to-end in ~5:39 on iad-ci.
All three checks pass: fmt, clippy, test.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-18 23:03:21 -04:00
jedarden
111a128278 P12.OP2: Update Raft vs Redis research with web survey findings
Add rrqlite/openraft+SQLite reference project, correct raft-rs status
to maintenance mode, note openraft 0.10 edition 2024 requirement, and
add additional production users (Helyim, RobustMQ, rrqlite).

Decision unchanged: do not ship Raft in v0.x or v1.0, revisit before v2.0.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-18 22:03:29 -04:00
jedarden
e47c1c2f73 P12.OP3: Validate 2× transient load caveat and add CLI schedule window guard
- Add resharding load simulation model with real router hash functions
- Benchmark confirms storage amplification is exactly 2.0× and dual-write
  amplification is exactly 2.0× across all test matrix scenarios (1KB/10GB,
  10KB/100GB, 1MB/1TB), with hash distribution CV < 5% in all cases
- CLI window guard: resharding.allowed_windows config restricts resharding
  to named time windows (e.g. "02:00-06:00 UTC"), CLI refuses outside
  windows without --force
- Integration tests confirm rejection outside window, --force override,
  no-restriction mode, and disabled config handling

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-18 22:00:57 -04:00
jedarden
fec5aa5e74 P12.OP1: Chaos-test cutover race window + hard refusal policy
14 chaos tests validate shard migration write safety at every cutover
boundary. Key findings:

- AE on + delta pass: 0/1M loss (production default)
- AE off + delta pass: 0/50K loss (delta pass is sufficient alone)
- AE off + delta skipped: ~2% loss → hard refusal at config validation
- 3-node cluster cutover: 0 loss with delta pass

Hard-coded policy: MigrationCoordinator refuses migrations when both
anti-entropy is disabled and delta pass is skipped. Warning logged when
AE is disabled but delta pass remains active.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-18 22:00:21 -04:00
jedarden
81155beb0d P12.OP1: Shard migration write safety — cutover race window analysis
Adds 14 chaos tests validating zero-data-loss at the migration cutover
boundary under all AE/delta-pass configurations. Two new 3-node cluster
variants exercise multi-owner shard migration with cross-node drain
tracking.

Key results: 0/1M loss with AE+delta; 0/50K loss with delta alone;
~2% hypothetical loss with neither (hard-refused by policy). The
MigrationCoordinator blocks migration when both anti-entropy and delta
pass are disabled.

Also includes: anti-entropy cross-module validation gate, warning log
when AE disabled during migration, empirical results table in
docs/trade-offs.md, and plan §15 OP#1 status update to verified.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-18 21:52:34 -04:00
jedarden
232092ffbb P0.5: Implement Config struct mirroring plan §4/§13 YAML schema
Full serde-derived struct tree covering every block in plan §4 (MiroirConfig,
NodeConfig, TaskStoreConfig, AdminConfig, HealthConfig, ScatterConfig,
RebalancerConfig, ServerConfig, ConnectionPoolConfig, TaskRegistryConfig) and
all 21 §13 advanced-capability sub-structs (ReshardingConfig through
SearchUiConfig with nested auth/rate-limit/CSP/analytics structs), plus §14
horizontal-scaling structs (PeerDiscoveryConfig, LeaderElectionConfig, HpaConfig).

Includes:
- Layered loading via config crate: built-in defaults → file → env overrides
- Config::validate() with 14 cross-field rules (HA requires redis, scoped_key
  timing inversion, node group bounds, tenant affinity range checks, etc.)
- 10 unit tests: round-trip YAML, full plan example, minimal YAML defaults,
  and validation rejection cases

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-18 21:46:12 -04:00
jedarden
188fd5404c P12.OP5: Add dump import compatibility matrix
Enumerates dump variants that streaming mode can/can't handle.

- Added docs/dump-import/compatibility-matrix.md with comprehensive
  compatibility matrix covering Meilisearch versions, dump variants,
  and workarounds
- Added docs/dump-import/README.md as entry point
- Updated miroir-ctl dump command to reference matrix with helpful
  error messages for unimplemented subcommands (import, export, analyze)

Addresses Open Problem #5: identifies what "can't reconstruct" means
in concrete terms, giving operators clear guidance on when broadcast
fallback is needed and what alternatives exist.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-18 21:06:46 -04:00
jedarden
fe274a5c0e P12.OP2: Add Raft vs Redis task store HA research doc
Survey openraft, raft-rs, and async-raft crates. Design a Raft-backed
TaskStore prototype using openraft with SQLite state machine. Analytical
benchmark against Redis across latency, throughput, memory, and ops
complexity. Decision: revisit before v2.0, do not ship in v0.x/v1.0 —
Raft fails the decision gate (worse on write latency and correctness
maturity despite removing the Redis dependency).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-18 21:00:53 -04:00
jedarden
409f952f59 Add repo hygiene: LICENSE, CHANGELOG, .gitignore
- LICENSE: MIT (per plan §12)
- CHANGELOG.md: Keep a Changelog 1.1.0 skeleton with [Unreleased]
  and [0.1.0] sections matching the awk extractor from plan §7
- .gitignore: Rust target/, editor junk; Cargo.lock kept in VCS

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-04-18 20:47:36 -04:00