Add live server performance monitoring

server/server.js

@@ -71,6 +71,7 @@ import { createYtdlpPool } from './ytdlp-pool.js';
 import { createWarmQueue } from './warm-queue.js';
 import { registerDeepSearchRoutes } from './deep-search.js';
 import { dirname, join as pathJoin } from 'node:path';
+import { createRequestMonitor, registerRequestMonitorRoutes } from './request-monitor.js';
 
 // A media proxy must not die because one client's stream hit an edge case
 // (see /api/play cancel()): log and keep serving instead of crash-looping.
@@ -346,6 +347,17 @@ function channelToUrl(c) {
 
 const app = new Hono();
 app.use('*', logger());
+const requestMonitor = createRequestMonitor({
+  snapshotFile: pathJoin(dirname(process.env.DB_PATH || './data/ytplayer.db'), 'ops-metrics.jsonl'),
+  diskPaths: [{ name: 'app-data', path: dirname(process.env.DB_PATH || './data/ytplayer.db') }, { name: 'media', path: process.env.MEDIA_DIR || './data/media' }],
+  adapters: {
+    ytdlp: () => ytdlpPool ? ytdlpPool.stats() : null,
+    media: () => media?.stats ? media.stats() : null,
+    transcription: () => notesDb.transcriptionStats?.() || null,
+    cache: () => ({ ...searchCacheCounters, memoryEntries: searchCache.size }),
+  },
+});
+app.use('*', requestMonitor.middleware());
 registerCatalogRoutes(app, { resolveListener: recommendationListener });
 
 // ============================================================================
@@ -383,6 +395,7 @@ const SEARCH_CACHE_TTL_MS = 10 * 60_000;          // fresh: answered from memory
 const SEARCH_CACHE_STALE_MS = 15 * 24 * 3600_000; // persistent copy: stale-while-revalidate for 15 days
 const searchCache = new Map(); // lowercased q -> { yt, fetchedAt }  (YouTube cards only)
 const inflightSearches = new Map(); // lowercased q -> Promise<{ yt, youtubeError? }>
+const searchCacheCounters = { hits: 0, misses: 0 };
 
 // The YouTube side of one search (up to 200 cards), shared by every caller asking
 // the same thing at the same time, and written to memory + the persistent cache.
@@ -452,11 +465,13 @@ app.get('/api/search', async (c) => {
       if (row) { hit = { yt: row.results, fetchedAt: row.fetchedAt }; searchCache.set(key, hit); }
     }
     const age = hit ? Date.now() - hit.fetchedAt : Infinity;
-    if (hit && age < SEARCH_CACHE_TTL_MS) return answer(hit.yt, { fetchedAt: hit.fetchedAt });
+    if (hit && age < SEARCH_CACHE_TTL_MS) { searchCacheCounters.hits++; return answer(hit.yt, { fetchedAt: hit.fetchedAt }); }
     if (hit && age < SEARCH_CACHE_STALE_MS) {
+      searchCacheCounters.hits++;
       fetchYoutube(q).catch(() => { /* keep serving the stale copy */ });
       return answer(hit.yt, { stale: true, fetchedAt: hit.fetchedAt });
     }
+    searchCacheCounters.misses++;
   }
   try {
     const { yt, fetchedAt } = await fetchYoutube(q);
@@ -2340,6 +2355,7 @@ const uploads = registerUploadRoutes(app, {
   parseLrc,
   sanitizeLyrics,
 });
+registerRequestMonitorRoutes(app, { adminAuth: notes.requireAdminOrToken, monitor: requestMonitor });
 const isUpload = (id) => uploads.isUploadId(id);
 
 // ============================================================================