fix(server): use separate writable DB for access logs

The memory_access_log table was created in the main MCP DB which is
opened readonly, so the table never existed and usage-stats always
returned empty accesses. Move access logs to a dedicated writable
SQLite DB injected via RouterOptions.accessLogDb.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: pfillion42

PLAN.md

@@ -194,6 +194,26 @@ avec une interface web moderne et une API backend. Interfacable avec Claude.
 - Build client OK
 - Audit securite : pas de vulnerabilite specifique au sprint, points preexistants (rate-limit, helmet, zod) dans backlog Sprint 8.2
 
+## Sprint 14 - DB separee pour les logs d'acces
+
+### 14.1 Refactoring access log DB - COMPLETE
+- Nouveau fichier `server/src/access-log-db.ts` : singleton writable (pattern identique a db.ts)
+- Chemin : `ACCESS_LOG_DB_PATH` env var, ou derive de `MEMORY_DB_PATH` (remplace .db par _access.db)
+- Table `memory_access_log` + index crees au premier appel, pas de sqlite-vec requis
+- `RouterOptions.accessLogDb` optionnel dans createMemoriesRouter
+- POST /:hash/access : UPDATE metadata dans main DB (try/catch readonly), INSERT dans accessLogDb
+- GET /usage-stats : lecture des acces depuis accessLogDb au lieu de la DB principale
+- Comportement graceful si accessLogDb absent (tableau vide, pas d'erreur)
+- `memory_access_log` retiree du schema test principal, nouvelle fonction `createTestAccessLogDb()`
+- 2 nouveaux tests : POST /access avec main DB readonly + GET /usage-stats lit depuis DB separee
+- Correction lint pre-existante (hasRating non utilise)
+
+### Bilan Sprint 14
+- 2 nouveaux tests backend
+- Total : 339 tests (213 serveur + 126 client), tous verts
+- Lint serveur OK
+- Build client inchange
+
 ## Backlog - Fonctionnalites futures
 
 ### Exploration et comprehension
@@ -228,7 +248,8 @@ avec une interface web moderne et une API backend. Interfacable avec Claude.
 - Chemin DB : via variable d'environnement `MEMORY_DB_PATH` (requis, defini dans server/.env)
 - Schema : 5 tables (memories, memory_content_fts fts5, memory_embeddings vec0, memory_graph, metadata)
 - Embedding : all-MiniLM-L6-v2 (384 dims, cosine distance)
-- Injection de dependance : `createMemoriesRouter(db)` pour faciliter les tests
+- Injection de dependance : `createMemoriesRouter(db, { accessLogDb, embedFn })` pour faciliter les tests
+- Access log : DB separee writable (`access-log-db.ts`), derive de MEMORY_DB_PATH si ACCESS_LOG_DB_PATH absent
 - Frontend : React Query + React Router, hooks custom, theme sombre via CSS custom properties
 - Navigation : / (Dashboard), /timeline (Timeline), /memories (MemoryList), /memories/:hash (MemoryDetail), /duplicates (Duplicates), /tags (Tags), /stale (Stale), /embeddings (EmbeddingView), /clusters (ClusterView), /graph (GraphView)
 - Embedder : @huggingface/transformers (all-MiniLM-L6-v2), injection de dependance pour tests
@@ -258,3 +279,4 @@ avec une interface web moderne et une API backend. Interfacable avec Claude.
 | 2026-02-15 | Sprint 13 clustering semantique | UnionFind classe, GET clusters, ClusterView, ScatterPlot colorMap, 314 tests verts |
 | 2026-02-15 | Sprint 8.2 securite secondaire | helmet, rate-limit, token API, validation zod (8 schemas), 337 tests verts |
 | 2026-02-15 | Lanceur desktop | start/stop-memviz.bat/.ps1, raccourci bureau avec icone SVG→ICO, detection services existants |
+| 2026-02-15 | Sprint 14 DB separee access log | access-log-db.ts singleton, refactoring POST /access + GET /usage-stats, 339 tests verts |

server/.env.example

@@ -7,5 +7,8 @@ MEMORY_DB_PATH=/chemin/vers/sqlite_vec.db
 # Origines CORS autorisees (separer par des virgules)
 # CORS_ORIGINS=http://localhost:5173,http://127.0.0.1:5173
 
+# Chemin vers la base access log (optionnel, derive de MEMORY_DB_PATH si absent)
+# ACCESS_LOG_DB_PATH=/chemin/vers/sqlite_vec_access.db
+
 # Interface d'ecoute (127.0.0.1 par defaut = localhost seulement)
 # HOST=127.0.0.1

server/src/access-log-db.ts

@@ -0,0 +1,36 @@
+import Database, { Database as DatabaseType } from 'better-sqlite3';
+
+const ACCESS_LOG_SCHEMA = `
+  CREATE TABLE IF NOT EXISTS memory_access_log (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    content_hash TEXT NOT NULL,
+    accessed_at REAL NOT NULL
+  );
+  CREATE INDEX IF NOT EXISTS idx_access_log_at ON memory_access_log(accessed_at);
+`;
+
+let accessLogDb: DatabaseType | null = null;
+
+function deriveAccessLogPath(): string {
+  const mainPath = process.env.MEMORY_DB_PATH;
+  if (!mainPath) {
+    throw new Error('ACCESS_LOG_DB_PATH ou MEMORY_DB_PATH requis pour la base access log.');
+  }
+  return mainPath.replace(/\.db$/, '_access.db');
+}
+
+export function getAccessLogDb(): DatabaseType {
+  if (!accessLogDb) {
+    const dbPath = process.env.ACCESS_LOG_DB_PATH || deriveAccessLogPath();
+    accessLogDb = new Database(dbPath);
+    accessLogDb.exec(ACCESS_LOG_SCHEMA);
+  }
+  return accessLogDb;
+}
+
+export function closeAccessLogDb(): void {
+  if (accessLogDb) {
+    accessLogDb.close();
+    accessLogDb = null;
+  }
+}

server/src/index.ts

@@ -4,6 +4,7 @@ import cors from 'cors';
 import helmet from 'helmet';
 import rateLimit from 'express-rate-limit';
 import { getDb, closeDb } from './db';
+import { getAccessLogDb, closeAccessLogDb } from './access-log-db';
 import { createMemoriesRouter } from './routes/memories';
 import { initEmbedder, getEmbedder } from './embedder';
 
@@ -71,8 +72,8 @@ async function start() {
     console.warn('Embedder non disponible - recherche vectorielle desactivee.', err);
   }
 
-  // Routes memories (avec embedder si disponible)
-  app.use('/api', createMemoriesRouter(getDb(), { embedFn }));
+  // Routes memories (avec embedder et access log DB si disponibles)
+  app.use('/api', createMemoriesRouter(getDb(), { embedFn, accessLogDb: getAccessLogDb() }));
 
   if (process.env.NODE_ENV !== 'test') {
     // Securite : ecouter uniquement sur localhost (pas expose au reseau)
@@ -85,9 +86,10 @@ async function start() {
 
 start();
 
-// Fermer la DB proprement a l'arret
+// Fermer les DB proprement a l'arret
 process.on('SIGINT', () => {
   closeDb();
+  closeAccessLogDb();
   process.exit(0);
 });
 

server/src/routes/memories.ts

@@ -108,6 +108,7 @@ function parseMemory(row: MemoryRow) {
 
 interface RouterOptions {
   embedFn?: EmbedFn;
+  accessLogDb?: DatabaseType;
 }
 
 // Securite : assainir les entrees FTS5 MATCH (retirer les operateurs speciaux)
@@ -175,20 +176,6 @@ export class UnionFind {
 export function createMemoriesRouter(db: DatabaseType, options: RouterOptions = {}): Router {
   const router = Router();
 
-  // Creer la table memory_access_log si elle n'existe pas (try/catch pour DB readonly)
-  try {
-    db.exec(`
-      CREATE TABLE IF NOT EXISTS memory_access_log (
-        id INTEGER PRIMARY KEY AUTOINCREMENT,
-        content_hash TEXT NOT NULL,
-        accessed_at REAL NOT NULL
-      );
-      CREATE INDEX IF NOT EXISTS idx_access_log_at ON memory_access_log(accessed_at);
-    `);
-  } catch {
-    // DB en lecture seule, la table n'existe peut-etre pas
-  }
-
   // GET /api/memories/vector-search - recherche par similarite vectorielle
   router.get('/memories/vector-search', async (req: Request, res: Response) => {
     const q = req.query.q as string | undefined;
@@ -748,17 +735,19 @@ export function createMemoriesRouter(db: DatabaseType, options: RouterOptions =
       ORDER BY date ASC
     `).all() as { date: string; count: number }[];
 
-    // Acces par periode (depuis memory_access_log)
+    // Acces par periode (depuis la DB de log separee)
     let accesses: { date: string; count: number }[] = [];
-    try {
-      accesses = db.prepare(`
-        SELECT ${accessDateExpr} as date, COUNT(*) as count
-        FROM memory_access_log
-        GROUP BY date
-        ORDER BY date ASC
-      `).all() as { date: string; count: number }[];
-    } catch {
-      // Table absente
+    if (options.accessLogDb) {
+      try {
+        accesses = options.accessLogDb.prepare(`
+          SELECT ${accessDateExpr} as date, COUNT(*) as count
+          FROM memory_access_log
+          GROUP BY date
+          ORDER BY date ASC
+        `).all() as { date: string; count: number }[];
+      } catch {
+        // Table absente
+      }
     }
 
     res.json({ period, creations, accesses });
@@ -1011,19 +1000,22 @@ export function createMemoriesRouter(db: DatabaseType, options: RouterOptions =
     const now = Math.floor(Date.now() / 1000);
     metadata.last_accessed_at = now;
 
-    db.prepare(`
-      UPDATE memories
-      SET metadata = ?
-      WHERE content_hash = ?
-    `).run(JSON.stringify(metadata), hash);
-
-    // Enregistrer l'acces dans le log
+    // Mise a jour metadata dans la DB principale (try/catch pour DB readonly)
     try {
       db.prepare(`
+        UPDATE memories
+        SET metadata = ?
+        WHERE content_hash = ?
+      `).run(JSON.stringify(metadata), hash);
+    } catch {
+      // DB en lecture seule, la mise a jour de metadata est ignoree
+    }
+
+    // Enregistrer l'acces dans la DB de log separee
+    if (options.accessLogDb) {
+      options.accessLogDb.prepare(`
         INSERT INTO memory_access_log (content_hash, accessed_at) VALUES (?, ?)
       `).run(hash, now);
-    } catch {
-      // Table absente (DB readonly sans migration), on ignore
     }
 
     res.json({
@@ -1042,7 +1034,6 @@ export function createMemoriesRouter(db: DatabaseType, options: RouterOptions =
     const { rating, score } = body;
 
     const hasScore = score !== undefined && score !== null;
-    const hasRating = rating !== undefined && rating !== null;
 
     const row = db.prepare(
       'SELECT * FROM memories WHERE content_hash = ? AND deleted_at IS NULL'

server/tests/helpers/test-db.ts

@@ -77,12 +77,6 @@ const SCHEMA = `
     value TEXT NOT NULL
   );
 
-  CREATE TABLE IF NOT EXISTS memory_access_log (
-    id INTEGER PRIMARY KEY AUTOINCREMENT,
-    content_hash TEXT NOT NULL,
-    accessed_at REAL NOT NULL
-  );
-  CREATE INDEX IF NOT EXISTS idx_access_log_at ON memory_access_log(accessed_at);
 `;
 
 const SEED_DATA: TestMemory[] = [
@@ -248,15 +242,6 @@ const SEED_METADATA = [
   { key: 'fts5_enabled', value: 'true' },
 ];
 
-// Acces seed : quelques entrees sur 2 jours differents
-const SEED_ACCESS_LOG = [
-  { content_hash: 'hash_aaa111', accessed_at: 1771000100 }, // 2026-02-13
-  { content_hash: 'hash_aaa111', accessed_at: 1771000200 }, // 2026-02-13
-  { content_hash: 'hash_bbb222', accessed_at: 1771088500 }, // 2026-02-14
-  { content_hash: 'hash_eee555', accessed_at: 1771088600 }, // 2026-02-14
-  { content_hash: 'hash_eee555', accessed_at: 1771088700 }, // 2026-02-14
-];
-
 export function createTestDb(): DatabaseType {
   const db = new Database(':memory:');
   sqliteVec.load(db);
@@ -291,15 +276,10 @@ export function createTestDb(): DatabaseType {
     INSERT INTO metadata (key, value) VALUES (@key, @value)
   `);
 
-  const insertAccessLog = db.prepare(`
-    INSERT INTO memory_access_log (content_hash, accessed_at) VALUES (@content_hash, @accessed_at)
-  `);
-
   const seedAll = db.transaction(() => {
     for (const m of SEED_DATA) insertMemory.run(m);
     for (const g of SEED_GRAPH) insertGraph.run(g);
     for (const m of SEED_METADATA) insertMeta.run(m);
-    for (const a of SEED_ACCESS_LOG) insertAccessLog.run(a);
 
     // Inserer des embeddings factices pour les memoires (id 1-5)
     for (let i = 1; i <= SEED_DATA.length; i++) {
@@ -315,6 +295,35 @@ export function createTestDb(): DatabaseType {
   return db;
 }
 
+// Acces seed : quelques entrees sur 2 jours differents
+const SEED_ACCESS_LOG = [
+  { content_hash: 'hash_aaa111', accessed_at: 1771000100 }, // 2026-02-13
+  { content_hash: 'hash_aaa111', accessed_at: 1771000200 }, // 2026-02-13
+  { content_hash: 'hash_bbb222', accessed_at: 1771088500 }, // 2026-02-14
+  { content_hash: 'hash_eee555', accessed_at: 1771088600 }, // 2026-02-14
+  { content_hash: 'hash_eee555', accessed_at: 1771088700 }, // 2026-02-14
+];
+
+export function createTestAccessLogDb(): DatabaseType {
+  const db = new Database(':memory:');
+  db.exec(`
+    CREATE TABLE memory_access_log (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      content_hash TEXT NOT NULL,
+      accessed_at REAL NOT NULL
+    );
+    CREATE INDEX idx_access_log_at ON memory_access_log(accessed_at);
+  `);
+
+  const insert = db.prepare(
+    'INSERT INTO memory_access_log (content_hash, accessed_at) VALUES (@content_hash, @accessed_at)'
+  );
+
+  for (const a of SEED_ACCESS_LOG) insert.run(a);
+
+  return db;
+}
+
 // Nombre de memoires non-supprimees dans le seed
 export const ACTIVE_MEMORY_COUNT = SEED_DATA.filter(m => m.deleted_at === null).length;
 export const TOTAL_MEMORY_COUNT = SEED_DATA.length;