tackle client disconnects

split-proxy/index.js

@@ -12,6 +12,31 @@ app.use(express.json({
   type: 'application/json'
 }));
 
+// Request timeout middleware
+app.use((req, res, next) => {
+  // Set request timeout
+  req.setTimeout(config.requestTimeout, () => {
+    logger.error({
+      method: req.method,
+      url: req.url,
+      timeout: config.requestTimeout,
+    }, 'Request timeout');
+    
+    if (!res.headersSent) {
+      res.status(504).json({
+        jsonrpc: '2.0',
+        error: {
+          code: -32000,
+          message: 'Request timeout',
+        },
+        id: req.body?.id,
+      });
+    }
+  });
+  
+  next();
+});
+
 // Health check endpoint
 app.get('/health', (req, res) => {
   res.json({
@@ -60,6 +85,19 @@ const server = app.listen(config.port, () => {
   }, 'ETH JSON-RPC proxy started');
 });
 
+// Set server timeouts to be longer than request timeout
+// This prevents the server from closing connections while requests are in flight
+server.timeout = config.requestTimeout + 5000; // Add 5 seconds buffer
+server.keepAliveTimeout = config.requestTimeout + 5000;
+server.headersTimeout = config.requestTimeout + 6000; // Should be > keepAliveTimeout
+
+logger.info({
+  serverTimeout: server.timeout,
+  keepAliveTimeout: server.keepAliveTimeout,
+  headersTimeout: server.headersTimeout,
+  requestTimeout: config.requestTimeout,
+}, 'Server timeout configuration');
+
 // Graceful shutdown
 process.on('SIGTERM', () => {
   logger.info('SIGTERM received, shutting down gracefully');

split-proxy/proxy.js

@@ -146,14 +146,54 @@ class RPCProxy {
 
     // Handle client disconnect
     let clientClosed = false;
+    let clientCloseReason = null;
+    
     req.on('close', () => {
+      if (!clientClosed) {
         clientClosed = true;
-      logger.warn({ requestId }, 'Client connection closed');
+        clientCloseReason = 'connection_closed';
+        logger.warn({ 
+          requestId,
+          reason: clientCloseReason,
+          headers: req.headers,
+          userAgent: req.headers['user-agent'],
+          contentLength: req.headers['content-length'],
+          method: requestBody.method,
+          elapsedMs: Date.now() - startTime,
+        }, 'Client connection closed');
+      }
     });
 
     req.on('error', (error) => {
+      if (!clientClosed) {
         clientClosed = true;
-      logger.error({ requestId, error: error.message }, 'Client connection error');
+        clientCloseReason = `connection_error: ${error.code || error.message}`;
+        logger.error({ 
+          requestId, 
+          error: error.message,
+          code: error.code,
+          reason: clientCloseReason,
+          headers: req.headers,
+          method: requestBody.method,
+          elapsedMs: Date.now() - startTime,
+        }, 'Client connection error');
+      }
+    });
+
+    // Also track response close events
+    res.on('close', () => {
+      if (!clientClosed) {
+        clientClosed = true;
+        clientCloseReason = 'response_closed';
+        logger.warn({
+          requestId,
+          reason: clientCloseReason,
+          finished: res.finished,
+          headersSent: res.headersSent,
+          method: requestBody.method,
+          elapsedMs: Date.now() - startTime,
+        }, 'Response connection closed');
+      }
     });
 
     try {
@@ -228,9 +268,15 @@ class RPCProxy {
       // Set response headers only if client hasn't closed
       if (!isClientClosed() && !res.headersSent) {
         res.status(response.status);
+        
+        // Ensure proper keep-alive handling
+        res.setHeader('Connection', 'keep-alive');
+        res.setHeader('Keep-Alive', `timeout=${Math.floor(config.requestTimeout / 1000)}`);
+        
         Object.entries(response.headers).forEach(([key, value]) => {
           // Remove content-encoding since we're requesting uncompressed
-          if (key.toLowerCase() !== 'content-encoding') {
+          // Don't override Connection header we just set
+          if (key.toLowerCase() !== 'content-encoding' && key.toLowerCase() !== 'connection') {
             res.setHeader(key, value);
           }
         });