cobalt/docs/websocket-stability-completion.md

WebSocket Connection Stability Improvements - Completion Report

Overview

Successfully implemented comprehensive WebSocket connection stability improvements to resolve the production environment disconnection issues in the clipboard sharing application.

Completed Improvements

1. GKE Load Balancer Configuration ✅

Helm Chart Enhancements

• File: cobalt-chart/values.yaml
• Changes: Added WebSocket-specific timeout configurations in Ingress annotations
• Impact: 1-hour connection timeout instead of default 30 seconds

BackendConfig Resource

• File: cobalt-chart/templates/backendconfig.yaml
• Features:
  • 1-hour backend timeout (timeoutSec: 3600)
  • Connection draining (60 seconds)
  • Client IP session affinity for WebSocket persistence
  • Custom health check targeting /health endpoint
  • CDN disabled for WebSocket compatibility

Service Annotations

• File: cobalt-chart/templates/service.yaml
• Features:
  • Links to WebSocket BackendConfig
  • GKE NEG annotations for proper load balancer integration

2. Server-Side Connection Monitoring ✅

Enhanced WebSocket Server

• File: api/src/core/signaling.js
• Features:
  • Advanced ping/pong monitoring with missed pong detection (max 3 missed)
  • Health check interval every 60 seconds
  • Connection age and activity tracking
  • Automatic cleanup of stale connections (2+ hours old with 5+ minutes inactivity)
  • Proper timer cleanup on connection close
  • Enhanced logging for connection diagnostics

Configuration Summary

Load Balancer Timeouts

# Ingress timeout
cloud.google.com/timeout-sec: "3600"

# Backend timeout  
timeoutSec: 3600
connectionDraining:
  drainingTimeoutSec: 60

Connection Monitoring

// Ping every 25 seconds
const pingInterval = setInterval(() => {
  // Check for missed pongs (max 3)
  // Send ping to keep connection alive
}, 25000);

// Health check every 60 seconds
const healthCheckInterval = setInterval(() => {
  // Monitor connection age and activity
  // Auto-cleanup stale connections
}, 60000);

Deployment Instructions

1. Deploy Updated Helm Chart

cd cobalt-chart
helm upgrade cobalt-api . --namespace production

2. Verify Deployment

# Check BackendConfig
kubectl get backendconfig websocket-backendconfig -o yaml

# Check Service annotations
kubectl get service -o yaml | grep -A5 annotations

# Check Ingress configuration
kubectl get ingress -o yaml | grep timeout-sec

3. Monitor WebSocket Connections

# Check server logs for enhanced connection monitoring
kubectl logs -f deployment/cobalt-api | grep -E "(WebSocket|Ping|Pong|Health check)"

Expected Results

Before Implementation

• WebSocket connections disconnecting after ~30 seconds in production
• Error codes: 1005 (No status received), 1006 (Abnormal closure)
• Manual reconnection required

After Implementation

• WebSocket connections stable for hours in production
• Automatic handling of network interruptions
• Proactive connection health monitoring
• Graceful cleanup of inactive connections

Monitoring and Validation

Connection Stability Metrics

• Average connection duration should increase from ~30 seconds to hours
• Reduction in abnormal closure codes (1005/1006)
• Improved user experience with fewer reconnection prompts

Health Check Validation

# Test health endpoints
curl https://api.freesavevideo.online/health
curl https://api.freesavevideo.online/ws/health

WebSocket Connection Test

// Browser console test
const ws = new WebSocket('wss://api.freesavevideo.online/ws');
ws.onopen = () => console.log('WebSocket connected successfully');
ws.onclose = (event) => console.log(`WebSocket closed: ${event.code}`);

Files Modified

1. cobalt-chart/values.yaml - Ingress timeout configuration
2. cobalt-chart/templates/backendconfig.yaml - GKE WebSocket backend config
3. cobalt-chart/templates/service.yaml - Service annotations for BackendConfig
4. api/src/core/signaling.js - Enhanced connection monitoring and health checks

Resolution Status

✅ COMPLETED - All WebSocket connection stability improvements have been successfully implemented and are ready for production deployment.

The solution addresses the root cause of production disconnections by:

1. Configuring appropriate GKE load balancer timeouts for WebSocket connections
2. Adding robust server-side connection monitoring and automatic cleanup
3. Implementing proactive health checks and connection management
4. Providing comprehensive logging for ongoing monitoring