tidaldb/docs
jx12n 44b768b8c6 feat(m11): sharding × replication + rebalancing (m11p6 L3-L5)
End the "replicated XOR sharded" split: S shard groups, each a
replication group at RF with its own elected leader, leaders balanced
across nodes; any gateway hash-routes.

- One unified write surface: /items,/embeddings,/signals hash-route to
  the owning shard group's leader (ShardRouter FNV-1a) AND replicate at
  RF. x-tidal-ack/x-tidal-seq, quorum await, NotLeader/QuorumTimeout are
  per-group; NotLeader names the group.
- Rebalance verbs (L3): POST /cluster/shards/{id}/transfer (fenced
  leadership move) + /cluster/shards/{id}/replicas (add/remove replica).
  A ?shard= selector threads through every per-shard admin verb and is
  propagated on intra-group forwards (ShardReplica::admin_path). S=1 is
  byte-for-byte (no selector, no shard in NotLeader body).
- Tier-3 exit gate (cluster_sharding.rs): 3 nodes × 3 shards × RF=3 over
  real OS processes — SIGKILL a node under ack=quorum load → only its
  shard-leaderships re-elect, reads never stop, zero acked loss across
  random kill points; plus a rebalance-verb test. Harness:
  MultiProcCluster::start_sharded.
- tidal-stress drives the single path (WritePath::Leader|Sharded gone),
  spreading writes round-robin across gateways or pinning --leader-url.
- Throughput: local 3×3 sustains 3,000 quorum signal-writes/s @ 0% err,
  ~30% CPU, lag ~0 (generator-bound). ≥5,000/s + ≥2.5× scaling is Ref-A.

Known follow-up (tracked): per-group-aware node readiness and cross-node
read fan-out under PARTIAL placement.
2026-06-13 18:23:43 -06:00
..
guides feat(m11): cluster security (m11p7) + perf instrumentation floor 2026-06-13 01:25:35 -06:00
ops feat(m11): observability+ops (m11p8) + perf-sweep wave 2 T2 2026-06-13 09:17:49 -06:00
planning feat(m11): sharding × replication + rebalancing (m11p6 L3-L5) 2026-06-13 18:23:43 -06:00
profiling feat(m11): cluster security (m11p7) + perf instrumentation floor 2026-06-13 01:25:35 -06:00
research chore: doc consolidation, seven-dimension review fixes, and commit hooks 2026-06-08 22:46:28 -06:00
reviews feat(m11): observability+ops (m11p8) + perf-sweep wave 2 T2 2026-06-13 09:17:49 -06:00
runbooks feat(m11): sharding × replication + rebalancing (m11p6 L3-L5) 2026-06-13 18:23:43 -06:00
specs feat(m11): sharding × replication + rebalancing (m11p6 L3-L5) 2026-06-13 18:23:43 -06:00
content-strategy.md feat: complete Milestone 5 — full-text search, RRF fusion, and creator search 2026-02-21 23:53:16 -07:00
personal-briefing-beachhead.md feat: M0p1 runtime skeleton, M0p2 tooling & diagnostics, m1p4 signal ledger 2026-02-20 20:32:00 -07:00
README.md feat(m11): membership, snapshot install, and reseed (m11p5) 2026-06-12 19:55:54 -06:00
roadmap-to-cluster.md feat(m11): sharding × replication + rebalancing (m11p6 L3-L5) 2026-06-13 18:23:43 -06:00

tidalDB Engineering Docs

The engineering documentation home. Top-level product docs (VISION, USE_CASES, SEQUENCE, ARCHITECTURE, API, QUICKSTART, CODING_GUIDELINES, thoughts) live at the repository root; everything below is the deeper engineering record.

This and the repo root are the two canonical doc homes. There is intentionally no per-crate doc mirror (no tidal/docs/). Edit the canonical file, never a copy.

Component specs — specs/

The authoritative component specifications (status: Implemented, M0M8).

# Spec # Spec
00 Architecture overview 08 Query engine
01 Storage engine 09 Ranking & scoring
02 Entity model 10 Feedback loop
03 Signal system 11 Schema
04 Relationships 12 Cold start
05 Cohorts 13 Concurrency
06 Text retrieval 14 Scale architecture
07 Vector retrieval

Planning — planning/

Code reviews — reviews/

Guides — guides/

Task-oriented, build-an-app docs (complements the root QUICKSTART.md and API.md):

Operations — ops/ and runbooks/

Research — research/

ANN (1, 2) · Tantivy (1, 2) · Signal ledger (1, 2) · WAL · Type system · Tooling & diagnostics · Enterprise-readiness risks

Profiling — profiling/

Hotspot analysis · Scale baselines · Signal memory · Signal rollup eval · Social scale · Tantivy merge tuning · USearch tuning

Strategy

Content strategy · Personal-briefing beachhead