# UAT Report: Phase 6 — The Mesh (Distributed Writes)

**Date:** 2026-02-02
**Phase/Feature:** Phase 6 (Distributed Writes) + Quickstart Update
**Tester:** Claude Opus 4.5
**Status:** PASS

## Summary

Full product walkthrough of StemeDB after Phase 6 completion. All existing functionality works correctly, all Phase 6 test suites pass, and the new cluster node binary demonstrates distributed routing. Quickstart updated with runnable cluster examples.

## Scope

What was tested:
- Full build and lint (`cargo build`, `cargo clippy`)
- Validation script (`scripts/validate.sh`)
- Single-node API server (`stemedb-api`)
- Swagger UI accessibility
- Go SDK examples (basic, conflict, skeptic)
- curl-based assertion/query workflow
- Skeptic and Layered endpoints
- Phase 6 crates: merkle, rpc, sync, cluster
- Replication battery tests (battery11)
- New cluster node binary (`stemedb-node`)
- Cluster gateway endpoints

What was NOT tested:
- Multi-node cluster with actual network communication (RPC forwarding not yet wired)
- Failure detection scenarios (SWIM probing)
- Range split/merge under load
- Production deployment configurations

## Environment

- Rust version: 1.75+ (stable)
- OS: Darwin 23.6.0 (macOS)
- Commit: main branch, post-Phase 6

## Test Results

### Build & Lint

| Test | Expected | Actual | Status |
|------|----------|--------|--------|
| `cargo build --workspace` | Compiles without errors | Compiled in 36.82s | PASS |
| `cargo clippy --workspace` | No warnings | 1 doc-comment warning (fixed) | PASS |
| `cargo fmt --all --check` | No diffs | Minor formatting diff (fixed) | PASS |

### Validation Script

| Test | Expected | Actual | Status |
|------|----------|--------|--------|
| Build complete | PASS | PASS | PASS |
| Server is healthy | PASS | PASS | PASS |
| Assertion created | PASS | Hash returned | PASS |
| Query returned data | PASS | 1 assertion | PASS |
| Lens query (Recency) | PASS | Winner returned | PASS |

### Go SDK Examples

| Test | Expected | Actual | Status |
|------|----------|--------|--------|
| `basic/main.go` | Creates assertion, queries back | Hash created, 1 result | PASS |
| `conflict/main.go` | Creates conflict, shows Skeptic/Layered | Contested status, tier resolution | PASS |
| `skeptic/main.go` | Seeds claims, analyzes conflict | 2 competing claims, conflict score 1.0 | PASS |

### API Endpoints (Single-Node)

| Test | Expected | Actual | Status |
|------|----------|--------|--------|
| `GET /v1/health` | 200, healthy status | `{"status":"healthy","version":"0.1.0"}` | PASS |
| `POST /v1/assert` | 201, hash returned | `{"hash":"...","status":"created"}` | PASS |
| `GET /v1/query` | 200, assertions array | `{"assertions":[...],"total_count":1}` | PASS |
| `GET /v1/skeptic` | 200, conflict analysis | Contested status, 2 claims | PASS |
| `GET /v1/layered` | 200, tier resolution | Clinical wins over Anecdotal | PASS |
| `GET /swagger-ui/` | 200 | HTTP 200 | PASS |

### Phase 6 Test Suites

| Crate | Tests | Expected | Actual | Status |
|-------|-------|----------|--------|--------|
| stemedb-merkle | 16 | All pass | 16/16 | PASS |
| stemedb-rpc | 5 | All pass | 5/5 | PASS |
| stemedb-sync | 10 | All pass | 10/10 | PASS |
| stemedb-cluster (gateway) | 10 | All pass | 10/10 | PASS |
| stemedb-cluster (membership) | 8 | All pass | 8/8 | PASS |
| stemedb-cluster (sharding) | 10 | All pass | 10/10 | PASS |
| battery11 replication | 8 | All pass | 8/8 | PASS |

### Cluster Node Binary

| Test | Expected | Actual | Status |
|------|----------|--------|--------|
| Binary builds | Compiles | Built in 3.54s | PASS |
| Node starts | Binds to port 4000 | Gateway listening | PASS |
| `GET /v1/health` | healthy: true | `{"healthy":true,"joined":true}` | PASS |
| `GET /v1/cluster/status` | Shows shards | 4 shards, version 1 | PASS |
| `GET /v1/route?subject=Tesla_Inc` | Returns shard | shard_id: 0 | PASS |
| `GET /v1/route?subject=Bitcoin` | Different shard | shard_id: 3 | PASS |
| `GET /v1/shards/0` | Shard metadata | replicas, size, generation | PASS |

### Routing Distribution

| Subject | Shard |
|---------|-------|
| Apple | 0 |
| Google | 2 |
| Semaglutide | 1 |
| Bitcoin | 3 |
| Central_Bank | 0 |
| Machine_Learning | 0 |
| Rust_Language | 3 |
| Climate_Change | 3 |

## Issues Found

### 1. Doc Comment Formatting in swim.rs

**Severity:** Low
**Status:** Fixed

Clippy flagged `doc_lazy_continuation` error at line 407 — missing blank line before continuation.

**Fix:** Added blank line in doc comment.

### 2. Health Endpoint Returns Unhealthy for Bootstrap Node

**Severity:** Medium
**Status:** Fixed

Single-node cluster reported `healthy: false` because the health check required `joined && !members.is_empty()`. A bootstrap node has no peers, so `members.is_empty()` was true.

**Fix:** Changed health check to just `joined` — a bootstrap node is healthy if it has joined (even with zero peers).

## Fixes Applied

1. `crates/stemedb-cluster/src/membership/swim.rs:407` — Added blank line in doc comment
2. `crates/stemedb-cluster/src/gateway/handlers.rs:275` — Changed health logic from `joined && !members.is_empty()` to `joined`
3. `cargo fmt --all` — Applied formatting fixes

## Artifacts

- Cluster node binary: `crates/stemedb-cluster/src/bin/node.rs`
- Updated quickstart: `quickstart.md` (Section 8: Distributed Mode)
- Test output: All 67 Phase 6 tests pass

## Recommendations

1. **Add multi-node integration test** — Spin up 2-3 nodes, verify SWIM discovery and gossip
2. **Wire RPC forwarding** — Gateway currently returns routing info but doesn't forward to storage nodes
3. **Add cluster validation script** — Similar to `scripts/validate.sh` but for cluster mode
4. **Document seed node configuration** — How to bootstrap a 3-node cluster

## Sign-Off

- [x] All critical tests pass
- [x] No blocking issues remain
- [x] Documentation updated (quickstart.md)
- [x] Ready for release
