fe8d0c87e7
2 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
jordan
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8aa1fbb414 |
vector search: normalize the query, instrument the blob path, expose per-group vector counts
Three real defects, plus a retracted fourth that was a probe artifact. P3 (fixed) - query/stored normalization asymmetry. The write path L2-normalized every stored vector; the read path passed the caller's raw query straight to the index, so the two sides lived in different spaces. With unit v, d = |q|^2 - 2q.v + 1, so a non-unit query shifted and scaled every distance by |q|^2. Measured live: 591-1174 against a documented [0,4], and an exact match scoring |q|^2 - 1 instead of ~0. vector_search_items now normalizes with the canonical l2_normalize; a zero-norm query (no direction, so nearest-by-cosine is undefined) is rejected with 400. Ranking is unchanged - |q|^2 and 1 are constant across candidates - which is why it went unnoticed; what broke was every absolute use of the number. WIRE-VISIBLE, recorded in CHANGELOG. P2 (fixed) - the blob path had zero instrumentation. Added per-kind tidaldb_cluster_blobs_originated/applied/apply_failed totals. Label cardinality is fixed at 4 by construction via a new BlobKind enum, and BlobRecord::blob_kind is now the ONE exhaustive match over the variants (kind() derives from it), so a new variant is a compile error in one place instead of a silent zero in three. Only the live apply path is counted - boot replay would inflate applied past originated on every restart. Coverage gap (fixed) - tidaldb_usearch_vector_count rendered only the metrics owner's shard group, so on a 3-group node two thirds of the corpus had no vector-count series at all. Co-located groups now render shard="N"; the owner stays unlabeled for wire compatibility, so an alert grouped by (shard) buckets each replica set separately without double-counting. P1 (RETRACTED) - the "replica-divergent vector index" does not exist. Every probe wrote through the /sharded/ surface, which hash-partitions and applies to the owning region's local store with no WAL append, and therefore does not replicate BY DESIGN (cluster/node.rs:8828-8829). A controlled A/B settled it: on /items plus /embeddings all 6 entities reach all 3 replicas; on the sharded surface four of six reach exactly one node. Both are now pinned by tests. See tmp/vector-search-correctness/diagnosis.md and the k3s-fleet cluster-state.yaml entry RETRACTED_blob_replication_rf1_2026_08_30. Pre-work: usearch_index.rs 872 to 503 lines by extracting its tests to a sibling (the project's existing path-attribute convention), and the three hand-rolled l2_normalize copies collapsed to one. The two entity copies used a zero threshold about 2900x looser than the canonical one; normalize_centroid now names the centroid zero-tolerance policy once, and a test pins the tightened behavior. Tests: 2107 lib (+5), 8 vector_search e2e (+4, three of which fail without the P3 fix), 4 cluster_sharding e2e (+2). The heavy multiproc tests in cluster_sharding are now serialized - four concurrent 3-node clusters made the pre-existing failover test miss its 10s budget. |
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jx12n
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bb21e69ae6 |
feat(m12): vector retrieval G1/G2 — recall harness, ANN in RETRIEVE, index tuning
m12p1 (measurement truth): TidalDb::vector_search_items pure k-NN probe + POST /vector_search (standalone + region node, merge-by-distance) + tidal-stress --verify-recall (deterministic id-keyed corpus, in-RAM brute-force cosine oracle, open-loop ramp → recall@k + true p99 + read-knee + JSON/gate exit). Repaired fabricated p99 columns (mean-as-p99) in social-scale.md / scale.rs. Verified real: recall@10=0.9997 at 20k/1536-D vs brute-force. m12p2 (G1 unblock): ANN candidate-gen wired into RETRIEVE — for_you=preference vector, related=seed embedding (similar_to), graceful scan-fallback. Cached per-signal-type top-K (signals/ledger/hot_top_k.rs, decay-order-invariant) so trending serves O(K). related over HTTP (FeedQuery.similar_to). Harness gains --feed-profile / --seed-preferences. Verified: trending retrieve p99 3.5-7.7ms. m12p3 (G2): per-query ef_search now honored (RwLock epoch-guard with_expansion, shared guard for same-ef concurrency) + dimension-aware brute→HNSW crossover usearch_min_vectors(dim) + memory_usage() + examples/ann_grid_search.rs. Measured 1536-D/100k clustered: default M=16/ef_c=400/F16/ef_s=200 clears G1+G2 (recall 0.997, p99 1.4ms); F16 -0.25% vs F32; Int8 rejected (-28%). Recall corpus is now clustered (Gaussian mixture) in grid + harness. |