cosmostat working

files/web/node_server/server.js

@@ -61,65 +61,66 @@ io.on('connection', async socket => {
 /* ---------- 3. Serve static files ----------------------------------- */
 /* --------------------------------------------------------------------- */
 app.use(express.static('public'));
+/* --- 4. Redis subscriber (patched) --------------------------------- */
+const redisClient = createClient({
+  url:      'redis://192.168.37.1:6379',
+  socket: { keepAlive: 60000, // 60 s TCP keep-alive
+            reconnectStrategy: attempts => Math.min(attempts * 100, 3000) } // back-off
+});
 
-/* --------------------------------------------------------------------- */
-/* ---------- 4. Redis subscriber ------------------------------------- */
-/* --------------------------------------------------------------------- */
-const redisClient = createClient({ url: 'redis://192.168.37.1:6379' });
 redisClient.on('error', err => console.error('Redis error', err));
 
 (async () => {
   await redisClient.connect();
-  const sub = redisClient.duplicate(); // duplicate to keep separate pub/sub
+
+  const sub = redisClient.duplicate();
   await sub.connect();
 
-  // Subscribe to the channel that sends host stats
-  await sub.subscribe(
-    ['host_metrics'],
-    (message, channel) => {
-      let payload;
-      try {
-        payload = JSON.parse(message); // message is a JSON string
-      } catch (e) {
-        console.error(`Failed to parse ${channel}`, e);
-        return;
-      }
-      io.emit(channel, payload);
+  // --------------------------------------------------------------------
+  // Helper that re-subscribes to a channel (and re-sends the handler)
+  // --------------------------------------------------------------------
+  async function safeSubscribe(channel, handler) {
+    try {
+      await sub.subscribe(channel, handler);
+      console.log(`Subscribed to ${channel}`);
+    } catch (e) {
+      console.error(`Failed to subscribe to ${channel}`, e);
     }
-  );
+  }
 
-  // Subscribe to the channel that sends host stats
-  await sub.subscribe(
-    ['client_summary'],
-    (message, channel) => {
-      let payload;
-      try {
-        payload = JSON.parse(message); // message is a JSON string
-      } catch (e) {
-        console.error(`Failed to parse ${channel}`, e);
-        return;
-      }
+  // ---------------------------------------------------------------
+  // Subscribe to all required channels
+  // ---------------------------------------------------------------
+  await safeSubscribe('host_metrics',   (msg) => forward('host_metrics',   msg));
+  await safeSubscribe('client_summary', (msg) => forward('client_summary', msg));
+
+  // ---------------------------------------------------------------
+  // Forward messages to Socket.io
+  // ---------------------------------------------------------------
+  function forward(channel, message) {
+    try {
+      const payload = JSON.parse(message);
       io.emit(channel, payload);
+    } catch (e) {
+      console.error(`Failed to parse message from ${channel}`, e);
     }
-  );
+  }
 
-  // Subscribe to the channel that sends host stats
-  await sub.subscribe(
-    ['client_hostnames'],
-    (message, channel) => {
-      let payload;
-      try {
-        payload = JSON.parse(message); // message is a JSON string
-      } catch (e) {
-        console.error(`Failed to parse ${channel}`, e);
-        return;
-      }
-      io.emit(channel, payload);
-    }
-  );
+  // ----------------------------------------------------------------
+  // Re-subscribe automatically when the Redis connection reconnects
+  // ----------------------------------------------------------------
+  sub.on('reconnecting', () => console.log('Redis reconnecting…'));
+  sub.on('ready', async () => {
+    console.log('Redis ready - re-subscribing to all channels');
+    await safeSubscribe('host_metrics',   (msg) => forward('host_metrics',   msg));
+    await safeSubscribe('client_summary', (msg) => forward('client_summary', msg));
+  });
 
-
-  sub.on('error', err => console.error('Subscriber error', err));
+  // Optional: if the connection ends for any reason, close the process
+  sub.on('end', () => {
+    console.error('Redis connection closed - exiting');
+    process.exit(1);
+  });
 })();
 
 /* --------------------------------------------------------------------- */