19.5.26

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@push.rocks/smartproxy",
-  "version": "19.5.24",
+  "version": "19.5.26",
   "private": false,
   "description": "A powerful proxy package with unified route-based configuration for high traffic management. Features include SSL/TLS support, flexible routing patterns, WebSocket handling, advanced security options, and automatic ACME certificate management.",
   "main": "dist_ts/index.js",

readme.connections.md

@@ -548,4 +548,177 @@ Debug scripts confirmed:
 - The zombie detection successfully identifies and cleans up these connections
 - Both full zombies (both sockets destroyed) and half-zombies (one socket destroyed) are handled
 
-This fix addresses the specific issue where "connections that are closed on the inner proxy, always also close on the outer proxy" as requested by the user.
+This fix addresses the specific issue where "connections that are closed on the inner proxy, always also close on the outer proxy" as requested by the user.
+
+## 🔍 Production Diagnostics (January 2025)
+
+Since the zombie detection fix didn't fully resolve the issue, use the ProductionConnectionMonitor to diagnose the actual problem:
+
+### How to Use the Production Monitor
+
+1. **Add to your proxy startup script**:
+```typescript
+import ProductionConnectionMonitor from './production-connection-monitor.js';
+
+// After proxy.start()
+const monitor = new ProductionConnectionMonitor(proxy);
+monitor.start(5000); // Check every 5 seconds
+
+// Monitor will automatically capture diagnostics when:
+// - Connections exceed threshold (default: 50)
+// - Sudden spike occurs (default: +20 connections)
+```
+
+2. **Diagnostics are saved to**: `.nogit/connection-diagnostics/`
+
+3. **Force capture anytime**: `monitor.forceCaptureNow()`
+
+### What the Monitor Captures
+
+For each connection:
+- Socket states (destroyed, readable, writable, readyState)
+- Connection flags (closed, keepAlive, TLS status)
+- Data transfer statistics
+- Time since last activity
+- Cleanup queue status
+- Event listener counts
+- Termination reasons
+
+### Pattern Analysis
+
+The monitor automatically identifies:
+- **Zombie connections**: Both sockets destroyed but not cleaned up
+- **Half-zombies**: One socket destroyed
+- **Stuck connecting**: Outgoing socket stuck in connecting state
+- **No outgoing**: Missing outgoing socket
+- **Keep-alive stuck**: Keep-alive connections with no recent activity
+- **Old connections**: Connections older than 1 hour
+- **No data transfer**: Connections with no bytes transferred
+- **Listener leaks**: Excessive event listeners
+
+### Common Accumulation Patterns
+
+1. **Connecting State Stuck**
+   - Outgoing socket shows `connecting: true` indefinitely
+   - Usually means connection timeout not working
+   - Check if backend is reachable
+
+2. **Missing Outgoing Socket**
+   - Connection has no outgoing socket but isn't closed
+   - May indicate immediate routing issues
+   - Check error logs during connection setup
+
+3. **Event Listener Accumulation**
+   - High listener counts (>20) on sockets
+   - Indicates cleanup not removing all listeners
+   - Can cause memory leaks
+
+4. **Keep-Alive Zombies**
+   - Keep-alive connections not timing out
+   - Check keepAlive timeout settings
+   - May need more aggressive cleanup
+
+### Next Steps
+
+1. **Run the monitor in production** during accumulation
+2. **Share the diagnostic files** from `.nogit/connection-diagnostics/`
+3. **Look for patterns** in the captured snapshots
+4. **Check specific connection IDs** that accumulate
+
+The diagnostic files will show exactly what state connections are in when accumulation occurs, allowing targeted fixes for the specific issue.
+
+## ✅ FIXED: Stuck Connection Detection (January 2025) 
+
+### Additional Root Cause Found
+Connections to hanging backends (that accept but never respond) were not being cleaned up because:
+- Both sockets remain alive (not destroyed)
+- Keep-alive prevents normal timeout
+- No data is sent back to the client despite receiving data
+- These don't qualify as "zombies" since sockets aren't destroyed
+
+### Fix Implemented
+Added stuck connection detection to the periodic inactivity check:
+
+```typescript
+// Check for stuck connections: no data sent back to client
+if (!record.connectionClosed && record.outgoing && record.bytesReceived > 0 && record.bytesSent === 0) {
+  const age = now - record.incomingStartTime;
+  // If connection is older than 60 seconds and no data sent back, likely stuck
+  if (age > 60000) {
+    logger.log('warn', `Stuck connection detected: ${connectionId} - received ${record.bytesReceived} bytes but sent 0 bytes`, {
+      connectionId,
+      remoteIP: record.remoteIP,
+      age: plugins.prettyMs(age),
+      bytesReceived: record.bytesReceived,
+      targetHost: record.targetHost,
+      targetPort: record.targetPort,
+      component: 'connection-manager'
+    });
+    
+    // Clean up
+    this.cleanupConnection(record, 'stuck_no_response');
+  }
+}
+```
+
+### What This Fixes
+- Connections to backends that accept but never respond
+- Proxy chains where inner proxy connects to unresponsive services
+- Scenarios where keep-alive prevents normal timeout mechanisms
+- Connections that receive client data but never send anything back
+
+### Detection Criteria
+- Connection has received bytes from client (`bytesReceived > 0`)
+- No bytes sent back to client (`bytesSent === 0`)
+- Connection is older than 60 seconds
+- Both sockets are still alive (not destroyed)
+
+This complements the zombie detection by handling cases where sockets remain technically alive but the connection is effectively dead.
+
+## 🚨 CRITICAL FIX: Cleanup Queue Bug (January 2025)
+
+### Critical Bug Found
+The cleanup queue had a severe bug that caused connection accumulation when more than 100 connections needed cleanup:
+
+```typescript
+// BUG: This cleared the ENTIRE queue after processing only the first batch!
+const toCleanup = Array.from(this.cleanupQueue).slice(0, this.cleanupBatchSize);
+this.cleanupQueue.clear(); // ❌ This discarded all connections beyond the first 100!
+```
+
+### Fix Implemented
+```typescript
+// Now only removes the connections being processed
+const toCleanup = Array.from(this.cleanupQueue).slice(0, this.cleanupBatchSize);
+for (const connectionId of toCleanup) {
+  this.cleanupQueue.delete(connectionId); // ✅ Only remove what we process
+  const record = this.connectionRecords.get(connectionId);
+  if (record) {
+    this.cleanupConnection(record, record.incomingTerminationReason || 'normal');
+  }
+}
+```
+
+### Impact
+- **Before**: If 150 connections needed cleanup, only the first 100 would be processed and the remaining 50 would accumulate forever
+- **After**: All connections are properly cleaned up in batches
+
+### Additional Improvements
+
+1. **Faster Inactivity Checks**: Reduced from 30s to 10s intervals
+   - Zombies and stuck connections are detected 3x faster
+   - Reduces the window for accumulation
+
+2. **Duplicate Prevention**: Added check in queueCleanup to prevent processing already-closed connections
+   - Prevents unnecessary work
+   - Ensures connections are only cleaned up once
+
+### Summary of All Fixes
+
+1. **Connection Timeout** (already documented) - Prevents accumulation when backends are unreachable
+2. **Zombie Detection** - Cleans up connections with destroyed sockets
+3. **Stuck Connection Detection** - Cleans up connections to hanging backends
+4. **Cleanup Queue Bug** - Ensures ALL connections get cleaned up, not just the first 100
+5. **Faster Detection** - Reduced check interval from 30s to 10s
+
+These fixes combined should prevent connection accumulation in all known scenarios.

readme.monitoring.md

@@ -0,0 +1,202 @@
+# Production Connection Monitoring
+
+This document explains how to use the ProductionConnectionMonitor to diagnose connection accumulation issues in real-time.
+
+## Quick Start
+
+```typescript
+import ProductionConnectionMonitor from './.nogit/debug/production-connection-monitor.js';
+
+// After starting your proxy
+const monitor = new ProductionConnectionMonitor(proxy);
+monitor.start(5000); // Check every 5 seconds
+
+// The monitor will automatically capture diagnostics when:
+// - Connections exceed 50 (default threshold)
+// - Sudden spike of 20+ connections occurs
+// - You manually call monitor.forceCaptureNow()
+```
+
+## What Gets Captured
+
+When accumulation is detected, the monitor saves a JSON file with:
+
+### Connection Details
+- Socket states (destroyed, readable, writable, readyState)
+- Connection age and activity timestamps
+- Data transfer statistics (bytes sent/received)
+- Target host and port information
+- Keep-alive status
+- Event listener counts
+
+### System State
+- Memory usage
+- Event loop lag
+- Connection count trends
+- Termination statistics
+
+## Reading Diagnostic Files
+
+Files are saved to `.nogit/connection-diagnostics/` with names like:
+```
+accumulation_2025-06-07T20-20-43-733Z_force_capture.json
+```
+
+### Key Fields to Check
+
+1. **Socket States**
+   ```json
+   "incomingState": {
+     "destroyed": false,
+     "readable": true,
+     "writable": true,
+     "readyState": "open"
+   }
+   ```
+   - Both destroyed = zombie connection
+   - One destroyed = half-zombie
+   - Both alive but old = potential stuck connection
+
+2. **Data Transfer**
+   ```json
+   "bytesReceived": 36,
+   "bytesSent": 0,
+   "timeSinceLastActivity": 60000
+   ```
+   - No bytes sent back = stuck connection
+   - High bytes but old = slow backend
+   - No activity = idle connection
+
+3. **Connection Flags**
+   ```json
+   "hasReceivedInitialData": false,
+   "hasKeepAlive": true,
+   "connectionClosed": false
+   ```
+   - hasReceivedInitialData=false on non-TLS = immediate routing
+   - hasKeepAlive=true = extended timeout applies
+   - connectionClosed=false = still tracked
+
+## Common Patterns
+
+### 1. Hanging Backend Pattern
+```json
+{
+  "bytesReceived": 36,
+  "bytesSent": 0,
+  "age": 120000,
+  "targetHost": "backend.example.com",
+  "incomingState": { "destroyed": false },
+  "outgoingState": { "destroyed": false }
+}
+```
+**Fix**: The stuck connection detection (60s timeout) should clean these up.
+
+### 2. Zombie Connection Pattern
+```json
+{
+  "incomingState": { "destroyed": true },
+  "outgoingState": { "destroyed": true },
+  "connectionClosed": false
+}
+```
+**Fix**: The zombie detection should clean these up within 30s.
+
+### 3. Event Listener Leak Pattern
+```json
+{
+  "incomingListeners": {
+    "data": 15,
+    "error": 20,
+    "close": 18
+  }
+}
+```
+**Issue**: Event listeners accumulating, potential memory leak.
+
+### 4. No Outgoing Socket Pattern
+```json
+{
+  "outgoingState": { "exists": false },
+  "connectionClosed": false,
+  "age": 5000
+}
+```
+**Issue**: Connection setup failed but cleanup didn't trigger.
+
+## Forcing Diagnostic Capture
+
+To capture current state immediately:
+```typescript
+monitor.forceCaptureNow();
+```
+
+This is useful when you notice accumulation starting.
+
+## Automated Analysis
+
+The monitor automatically analyzes patterns and logs:
+- Zombie/half-zombie counts
+- Stuck connection counts
+- Old connection counts
+- Memory usage
+- Recommendations
+
+## Integration Example
+
+```typescript
+// In your proxy startup script
+import { SmartProxy } from '@push.rocks/smartproxy';
+import ProductionConnectionMonitor from './production-connection-monitor.js';
+
+async function startProxyWithMonitoring() {
+  const proxy = new SmartProxy({
+    // your config
+  });
+  
+  await proxy.start();
+  
+  // Start monitoring
+  const monitor = new ProductionConnectionMonitor(proxy);
+  monitor.start(5000);
+  
+  // Optional: Capture on specific events
+  process.on('SIGUSR1', () => {
+    console.log('Manual diagnostic capture triggered');
+    monitor.forceCaptureNow();
+  });
+  
+  // Graceful shutdown
+  process.on('SIGTERM', async () => {
+    monitor.stop();
+    await proxy.stop();
+    process.exit(0);
+  });
+}
+```
+
+## Troubleshooting
+
+### Monitor Not Detecting Accumulation
+- Check threshold settings (default: 50 connections)
+- Reduce check interval for faster detection
+- Use forceCaptureNow() to capture current state
+
+### Too Many False Positives
+- Increase accumulation threshold
+- Increase spike threshold
+- Adjust check interval
+
+### Missing Diagnostic Data
+- Ensure output directory exists and is writable
+- Check disk space
+- Verify process has write permissions
+
+## Next Steps
+
+1. Deploy the monitor to production
+2. Wait for accumulation to occur
+3. Share diagnostic files for analysis
+4. Apply targeted fixes based on patterns found
+
+The diagnostic data will reveal the exact state of connections when accumulation occurs, enabling precise fixes for your specific scenario.

test/test.cleanup-queue-bug.node.ts

@@ -0,0 +1,93 @@
+import { expect, tap } from '@git.zone/tstest/tapbundle';
+import { SmartProxy } from '../ts/index.js';
+
+tap.test('cleanup queue bug - verify queue processing handles more than batch size', async (tools) => {
+  console.log('\n=== Cleanup Queue Bug Test ===');
+  console.log('Purpose: Verify that the cleanup queue correctly processes all connections');
+  console.log('even when there are more than the batch size (100)');
+  
+  // Create proxy
+  const proxy = new SmartProxy({
+    routes: [{
+      name: 'test-route',
+      match: { ports: 8588 },
+      action: {
+        type: 'forward',
+        target: { host: 'localhost', port: 9996 }
+      }
+    }],
+    enableDetailedLogging: false,
+  });
+  
+  await proxy.start();
+  console.log('✓ Proxy started on port 8588');
+  
+  // Access connection manager
+  const cm = (proxy as any).connectionManager;
+  
+  // Create mock connection records
+  console.log('\n--- Creating 150 mock connections ---');
+  const mockConnections: any[] = [];
+  
+  for (let i = 0; i < 150; i++) {
+    const mockRecord = {
+      id: `mock-${i}`,
+      incoming: { destroyed: true, remoteAddress: '127.0.0.1' },
+      outgoing: { destroyed: true },
+      connectionClosed: false,
+      incomingStartTime: Date.now(),
+      lastActivity: Date.now(),
+      remoteIP: '127.0.0.1',
+      remotePort: 10000 + i,
+      localPort: 8588,
+      bytesReceived: 100,
+      bytesSent: 100,
+      incomingTerminationReason: null,
+      cleanupTimer: null
+    };
+    
+    // Add to connection records
+    cm.connectionRecords.set(mockRecord.id, mockRecord);
+    mockConnections.push(mockRecord);
+  }
+  
+  console.log(`Created ${cm.getConnectionCount()} mock connections`);
+  expect(cm.getConnectionCount()).toEqual(150);
+  
+  // Queue all connections for cleanup
+  console.log('\n--- Queueing all connections for cleanup ---');
+  for (const conn of mockConnections) {
+    cm.initiateCleanupOnce(conn, 'test_cleanup');
+  }
+  
+  console.log(`Cleanup queue size: ${cm.cleanupQueue.size}`);
+  expect(cm.cleanupQueue.size).toEqual(150);
+  
+  // Wait for cleanup to complete
+  console.log('\n--- Waiting for cleanup batches to process ---');
+  
+  // The first batch should process immediately (100 connections)
+  // Then additional batches should be scheduled
+  await new Promise(resolve => setTimeout(resolve, 500));
+  
+  // Check final state
+  const finalCount = cm.getConnectionCount();
+  console.log(`\nFinal connection count: ${finalCount}`);
+  console.log(`Cleanup queue size: ${cm.cleanupQueue.size}`);
+  
+  // All connections should be cleaned up
+  expect(finalCount).toEqual(0);
+  expect(cm.cleanupQueue.size).toEqual(0);
+  
+  // Verify termination stats
+  const stats = cm.getTerminationStats();
+  console.log('Termination stats:', stats);
+  expect(stats.incoming.test_cleanup).toEqual(150);
+  
+  // Cleanup
+  await proxy.stop();
+  
+  console.log('\n✓ Test complete: Cleanup queue now correctly processes all connections');
+});
+
+tap.start();

test/test.stuck-connection-cleanup.node.ts

@@ -0,0 +1,144 @@
+import { expect, tap } from '@git.zone/tstest/tapbundle';
+import * as net from 'net';
+import { SmartProxy } from '../ts/index.js';
+import * as plugins from '../ts/plugins.js';
+
+tap.test('stuck connection cleanup - verify connections to hanging backends are cleaned up', async (tools) => {
+  console.log('\n=== Stuck Connection Cleanup Test ===');
+  console.log('Purpose: Verify that connections to backends that accept but never respond are cleaned up');
+  
+  // Create a hanging backend that accepts connections but never responds
+  let backendConnections = 0;
+  const hangingBackend = net.createServer((socket) => {
+    backendConnections++;
+    console.log(`Hanging backend: Connection ${backendConnections} received`);
+    // Accept the connection but never send any data back
+    // This simulates a hung backend service
+  });
+  
+  await new Promise<void>((resolve) => {
+    hangingBackend.listen(9997, () => {
+      console.log('✓ Hanging backend started on port 9997');
+      resolve();
+    });
+  });
+  
+  // Create proxy that forwards to hanging backend
+  const proxy = new SmartProxy({
+    routes: [{
+      name: 'to-hanging-backend',
+      match: { ports: 8589 },
+      action: {
+        type: 'forward',
+        target: { host: 'localhost', port: 9997 }
+      }
+    }],
+    keepAlive: true,
+    enableDetailedLogging: false,
+    inactivityTimeout: 5000, // 5 second inactivity check interval for faster testing
+  });
+  
+  await proxy.start();
+  console.log('✓ Proxy started on port 8589');
+  
+  // Create connections that will get stuck
+  console.log('\n--- Creating connections to hanging backend ---');
+  const clients: net.Socket[] = [];
+  
+  for (let i = 0; i < 5; i++) {
+    const client = net.connect(8589, 'localhost');
+    clients.push(client);
+    
+    await new Promise<void>((resolve) => {
+      client.on('connect', () => {
+        console.log(`Client ${i} connected`);
+        // Send data that will never get a response
+        client.write(`GET / HTTP/1.1\r\nHost: localhost\r\n\r\n`);
+        resolve();
+      });
+      
+      client.on('error', (err) => {
+        console.log(`Client ${i} error: ${err.message}`);
+        resolve();
+      });
+    });
+  }
+  
+  // Wait a moment for connections to establish
+  await plugins.smartdelay.delayFor(1000);
+  
+  // Check initial connection count
+  const initialCount = (proxy as any).connectionManager.getConnectionCount();
+  console.log(`\nInitial connection count: ${initialCount}`);
+  expect(initialCount).toEqual(5);
+  
+  // Get connection details
+  const connections = (proxy as any).connectionManager.getConnections();
+  let stuckCount = 0;
+  
+  for (const [id, record] of connections) {
+    if (record.bytesReceived > 0 && record.bytesSent === 0) {
+      stuckCount++;
+      console.log(`Stuck connection ${id}: received=${record.bytesReceived}, sent=${record.bytesSent}`);
+    }
+  }
+  
+  console.log(`Stuck connections found: ${stuckCount}`);
+  expect(stuckCount).toEqual(5);
+  
+  // Wait for inactivity check to run (it checks every 30s by default, but we set it to 5s)
+  console.log('\n--- Waiting for stuck connection detection (65 seconds) ---');
+  console.log('Note: Stuck connections are cleaned up after 60 seconds with no response');
+  
+  // Speed up time by manually triggering inactivity check after simulating time passage
+  // First, age the connections by updating their timestamps
+  const now = Date.now();
+  for (const [id, record] of connections) {
+    // Simulate that these connections are 61 seconds old
+    record.incomingStartTime = now - 61000;
+    record.lastActivity = now - 61000;
+  }
+  
+  // Manually trigger inactivity check
+  console.log('Manually triggering inactivity check...');
+  (proxy as any).connectionManager.performOptimizedInactivityCheck();
+  
+  // Wait for cleanup to complete
+  await plugins.smartdelay.delayFor(1000);
+  
+  // Check connection count after cleanup
+  const afterCleanupCount = (proxy as any).connectionManager.getConnectionCount();
+  console.log(`\nConnection count after cleanup: ${afterCleanupCount}`);
+  
+  // Verify termination stats
+  const stats = (proxy as any).connectionManager.getTerminationStats();
+  console.log('\nTermination stats:', stats);
+  
+  // All connections should be cleaned up as "stuck_no_response"
+  expect(afterCleanupCount).toEqual(0);
+  
+  // The termination reason might be under incoming or general stats
+  const stuckCleanups = (stats.incoming.stuck_no_response || 0) + 
+                       (stats.outgoing?.stuck_no_response || 0);
+  console.log(`Stuck cleanups detected: ${stuckCleanups}`);
+  expect(stuckCleanups).toBeGreaterThan(0);
+  
+  // Verify clients were disconnected
+  let closedClients = 0;
+  for (const client of clients) {
+    if (client.destroyed) {
+      closedClients++;
+    }
+  }
+  console.log(`Closed clients: ${closedClients}/5`);
+  expect(closedClients).toEqual(5);
+  
+  // Cleanup
+  console.log('\n--- Cleanup ---');
+  await proxy.stop();
+  hangingBackend.close();
+  
+  console.log('✓ Test complete: Stuck connections are properly detected and cleaned up');
+});
+
+tap.start();

ts/proxies/smart-proxy/connection-manager.ts

@@ -140,10 +140,10 @@ export class ConnectionManager extends LifecycleComponent {
    * Start the inactivity check timer
    */
   private startInactivityCheckTimer(): void {
-    // Check every 30 seconds for connections that need inactivity check
+    // Check more frequently (every 10 seconds) to catch zombies and stuck connections faster
     this.setInterval(() => {
       this.performOptimizedInactivityCheck();
-    }, 30000);
+    }, 10000);
     // Note: LifecycleComponent's setInterval already calls unref()
   }
 
@@ -194,6 +194,13 @@ export class ConnectionManager extends LifecycleComponent {
    * Queue a connection for cleanup
    */
   private queueCleanup(connectionId: string): void {
+    // Check if connection is already being processed
+    const record = this.connectionRecords.get(connectionId);
+    if (!record || record.connectionClosed) {
+      // Already cleaned up or doesn't exist, skip
+      return;
+    }
+    
     this.cleanupQueue.add(connectionId);
     
     // Process immediately if queue is getting large
@@ -217,9 +224,10 @@ export class ConnectionManager extends LifecycleComponent {
     }
     
     const toCleanup = Array.from(this.cleanupQueue).slice(0, this.cleanupBatchSize);
-    this.cleanupQueue.clear();
     
+    // Remove only the items we're processing, not the entire queue!
     for (const connectionId of toCleanup) {
+      this.cleanupQueue.delete(connectionId);
       const record = this.connectionRecords.get(connectionId);
       if (record) {
         this.cleanupConnection(record, record.incomingTerminationReason || 'normal');
@@ -495,6 +503,32 @@ export class ConnectionManager extends LifecycleComponent {
             this.cleanupConnection(record, 'half_zombie_cleanup');
           }
         }
+        
+        // Check for stuck connections: no data sent back to client
+        if (!record.connectionClosed && record.outgoing && record.bytesReceived > 0 && record.bytesSent === 0) {
+          const age = now - record.incomingStartTime;
+          // If connection is older than 60 seconds and no data sent back, likely stuck
+          if (age > 60000) {
+            logger.log('warn', `Stuck connection detected: ${connectionId} - received ${record.bytesReceived} bytes but sent 0 bytes`, {
+              connectionId,
+              remoteIP: record.remoteIP,
+              age: plugins.prettyMs(age),
+              bytesReceived: record.bytesReceived,
+              targetHost: record.targetHost,
+              targetPort: record.targetPort,
+              component: 'connection-manager'
+            });
+            
+            // Set termination reason and increment stats
+            if (record.incomingTerminationReason == null) {
+              record.incomingTerminationReason = 'stuck_no_response';
+              this.incrementTerminationStat('incoming', 'stuck_no_response');
+            }
+            
+            // Clean up
+            this.cleanupConnection(record, 'stuck_no_response');
+          }
+        }
       }
     }