添加valkey support

server/cache.js

@@ -0,0 +1,59 @@
+const Redis = require('ioredis');
+
+const host = process.env.VALKEY_HOST || 'localhost';
+const port = parseInt(process.env.VALKEY_PORT) || 6379;
+const password = process.env.VALKEY_PASSWORD || undefined;
+const db = parseInt(process.env.VALKEY_DB) || 0;
+const ttl = parseInt(process.env.VALKEY_TTL) || 30;
+
+let redis = null;
+
+try {
+  redis = new Redis({
+    host,
+    port,
+    password,
+    db,
+    lazyConnect: true,
+    maxRetriesPerRequest: 1
+  });
+
+  redis.on('error', (err) => {
+    // Fail silently after one retry, we just won't cache
+    console.warn('[Cache] Valkey connection failed, caching disabled:', err.message);
+  });
+} catch (err) {
+  console.warn('[Cache] Valkey init failed:', err.message);
+}
+
+const cache = {
+  async get(key) {
+    if (!redis) return null;
+    try {
+      const data = await redis.get(key);
+      return data ? JSON.parse(data) : null;
+    } catch (e) {
+      return null;
+    }
+  },
+
+  async set(key, value, customTtl = ttl) {
+    if (!redis) return;
+    try {
+      await redis.set(key, JSON.stringify(value), 'EX', customTtl);
+    } catch (e) {
+      // ignore
+    }
+  },
+
+  async del(key) {
+    if (!redis) return;
+    try {
+      await redis.del(key);
+    } catch (e) {
+      // ignore
+    }
+  }
+};
+
+module.exports = cache;

server/index.js

@@ -4,6 +4,7 @@ const cors = require('cors');
 const path = require('path');
 const db = require('./db');
 const prometheusService = require('./prometheus-service');
+const cache = require('./cache');
 const checkAndFixDatabase = require('./db-integrity-check');
 
 const app = express();
@@ -462,12 +463,20 @@ app.get('/api/metrics/overview', async (req, res) => {
       });
     }
 
-    const allMetrics = await Promise.all(sources.map(source =>
-      prometheusService.getOverviewMetrics(source.url, source.name).catch(err => {
+    const allMetrics = await Promise.all(sources.map(async (source) => {
+      const cacheKey = `source_metrics:${source.url}:${source.name}`;
+      const cached = await cache.get(cacheKey);
+      if (cached) return cached;
+
+      try {
+        const metrics = await prometheusService.getOverviewMetrics(source.url, source.name);
+        await cache.set(cacheKey, metrics, 15); // Cache for 15s
+        return metrics;
+      } catch (err) {
         console.error(`Error fetching metrics from ${source.name}:`, err.message);
         return null;
-      })
-    ));
+      }
+    }));
 
     const validMetrics = allMetrics.filter(m => m !== null);