#!/usr/bin/env node
/**
* SSE Connection Issues Fix Script
*
* This script provides comprehensive solutions for SSE connection close issues
* in the MCP Inspector and other SSE-based transports.
*
* Usage:
* node scripts/fix-sse-connection-issues.js [options]
*
* Options:
* --diagnose Run diagnostics only
* --fix Apply fixes
* --monitor Start monitoring mode
* --test Run connection stability test
*/
import fs from 'fs';
import path from 'path';
import { spawn, exec } from 'child_process';
import { fileURLToPath } from 'url';
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
class SSEConnectionFixer {
constructor() {
this.projectRoot = path.resolve(__dirname, '..');
this.fixes = [];
this.diagnostics = {};
}
async run() {
const args = process.argv.slice(2);
console.log('🔧 SSE Connection Issues Fix Script');
console.log('=====================================\n');
if (args.includes('--diagnose')) {
await this.runDiagnostics();
} else if (args.includes('--fix')) {
await this.applyFixes();
} else if (args.includes('--monitor')) {
await this.startMonitoring();
} else if (args.includes('--test')) {
await this.testConnection();
} else {
await this.runComplete();
}
}
async runDiagnostics() {
console.log('🔍 Running SSE Connection Diagnostics...\n');
// Check Node.js version
const nodeVersion = process.version;
console.log(`Node.js Version: ${nodeVersion}`);
if (this.compareVersions(nodeVersion, 'v18.0.0') < 0) {
this.fixes.push('upgrade-node');
console.log('⚠️ Node.js version is below recommended v18.0.0');
} else {
console.log('✅ Node.js version is compatible');
}
// Check MCP SDK version
const packageJson = this.readPackageJson();
const mcpSdkVersion = packageJson.dependencies?.['@modelcontextprotocol/sdk'];
console.log(`\nMCP SDK Version: ${mcpSdkVersion || 'not found'}`);
// Check for common issues
await this.checkCommonIssues();
// Check system resources
this.checkSystemResources();
// Generate recommendations
this.generateRecommendations();
}
async checkCommonIssues() {
console.log('\n🔍 Checking for common SSE issues...');
// Check for multiple inspector instances
try {
const { stdout } = await this.execCommand('lsof -i :6274 2>/dev/null || echo "No process found"');
if (stdout.includes('node')) {
console.log('⚠️ MCP Inspector port 6274 is in use');
this.fixes.push('kill-inspector-processes');
} else {
console.log('✅ MCP Inspector port is available');
}
} catch (error) {
console.log('ℹ️ Could not check port usage (lsof not available)');
}
// Check for zombie processes
try {
const { stdout } = await this.execCommand('ps aux | grep "mcp\\|inspector" | grep -v grep || echo "No processes found"');
const processes = stdout.split('\n').filter(line => line.trim() && !line.includes('No processes found'));
if (processes.length > 0) {
console.log(`⚠️ Found ${processes.length} MCP-related processes`);
processes.forEach(proc => console.log(` ${proc.trim()}`));
this.fixes.push('cleanup-processes');
} else {
console.log('✅ No zombie MCP processes found');
}
} catch (error) {
console.log('ℹ️ Could not check for zombie processes');
}
// Check file descriptors
try {
const { stdout } = await this.execCommand('ulimit -n');
const fdLimit = parseInt(stdout.trim());
if (fdLimit < 1024) {
console.log(`⚠️ Low file descriptor limit: ${fdLimit}`);
this.fixes.push('increase-fd-limit');
} else {
console.log(`✅ File descriptor limit is adequate: ${fdLimit}`);
}
} catch (error) {
console.log('ℹ️ Could not check file descriptor limit');
}
}
checkSystemResources() {
console.log('\n🔍 Checking system resources...');
const memUsage = process.memoryUsage();
const memUsedMB = memUsage.heapUsed / 1024 / 1024;
console.log(`Memory Usage: ${memUsedMB.toFixed(2)} MB`);
if (memUsedMB > 500) {
console.log('⚠️ High memory usage detected');
this.fixes.push('optimize-memory');
} else {
console.log('✅ Memory usage is normal');
}
// Check uptime
const uptimeSeconds = process.uptime();
console.log(`Process Uptime: ${(uptimeSeconds / 60).toFixed(1)} minutes`);
if (uptimeSeconds < 30) {
console.log('ℹ️ Process recently started, connections may still be stabilizing');
}
}
async applyFixes() {
console.log('🔧 Applying SSE Connection Fixes...\n');
for (const fix of this.fixes) {
await this.applyFix(fix);
}
if (this.fixes.length === 0) {
console.log('✅ No fixes needed - system appears healthy');
}
}
async applyFix(fixType) {
console.log(`\n🔧 Applying fix: ${fixType}`);
switch (fixType) {
case 'kill-inspector-processes':
await this.killInspectorProcesses();
break;
case 'cleanup-processes':
await this.cleanupProcesses();
break;
case 'increase-fd-limit':
this.increaseFDLimit();
break;
case 'optimize-memory':
this.optimizeMemory();
break;
case 'upgrade-node':
this.suggestNodeUpgrade();
break;
default:
console.log(`❓ Unknown fix type: ${fixType}`);
}
}
async killInspectorProcesses() {
try {
await this.execCommand('pkill -f "mcp.*inspector" || true');
await this.execCommand('pkill -f "inspector.*mcp" || true');
console.log('✅ Killed existing inspector processes');
// Wait a moment for cleanup
await new Promise(resolve => setTimeout(resolve, 2000));
} catch (error) {
console.log('⚠️ Could not kill inspector processes:', error.message);
}
}
async cleanupProcesses() {
try {
// Kill any hanging MCP processes
await this.execCommand('pkill -f "gmail-mcp-server" || true');
await this.execCommand('pkill -f "build/index.js" || true');
console.log('✅ Cleaned up MCP processes');
// Wait for cleanup
await new Promise(resolve => setTimeout(resolve, 2000));
} catch (error) {
console.log('⚠️ Could not cleanup processes:', error.message);
}
}
increaseFDLimit() {
console.log('ℹ️ To increase file descriptor limit, run:');
console.log(' ulimit -n 4096');
console.log(' Or add to ~/.bashrc or ~/.zshrc:');
console.log(' export ULIMIT_FD=4096');
}
optimizeMemory() {
console.log('ℹ️ Memory optimization suggestions:');
console.log(' - Restart the MCP server periodically');
console.log(' - Reduce batch sizes in operations');
console.log(' - Clear caches regularly');
console.log(' - Set NODE_OPTIONS="--max-old-space-size=2048"');
}
suggestNodeUpgrade() {
console.log('ℹ️ Node.js upgrade recommended:');
console.log(' - Current version may have SSE stability issues');
console.log(' - Upgrade to Node.js v18+ or v20+ for better SSE support');
console.log(' - Use nvm: nvm install 20 && nvm use 20');
}
async startMonitoring() {
console.log('📊 Starting SSE Connection Monitoring...\n');
// Build the project first
console.log('Building project...');
await this.execCommand('npm run build');
// Start monitoring
const monitorScript = `
const { globalConnectionMonitor } = require('./build/utils/ConnectionHealthMonitor.js');
const { monitorSSEIssues, logDiagnostics } = require('./build/tools/diagnostics.js');
console.log('🔍 SSE Connection Monitor Started');
console.log('Press Ctrl+C to stop monitoring\\n');
// Setup monitoring
monitorSSEIssues();
globalConnectionMonitor.startMonitoring();
// Log initial diagnostics
logDiagnostics();
// Periodic health checks
setInterval(() => {
const health = globalConnectionMonitor.getConnectionHealth();
console.log(\`[\${new Date().toISOString()}] Connection Health: \${health.quality} - \${health.isConnected ? 'Connected' : 'Disconnected'}\`);
}, 10000);
process.on('SIGINT', () => {
console.log('\\n🛑 Stopping monitor...');
globalConnectionMonitor.stopMonitoring();
process.exit(0);
});
`;
fs.writeFileSync(path.join(this.projectRoot, 'temp-monitor.js'), monitorScript);
try {
await this.execCommand('node temp-monitor.js');
} finally {
// Cleanup
try {
fs.unlinkSync(path.join(this.projectRoot, 'temp-monitor.js'));
} catch (e) {}
}
}
async testConnection() {
console.log('🧪 Testing SSE Connection Stability...\n');
// Build first
await this.execCommand('npm run build');
console.log('Starting MCP Inspector for testing...');
const inspector = spawn('npm', ['run', 'inspector'], {
cwd: this.projectRoot,
stdio: ['pipe', 'pipe', 'pipe']
});
let output = '';
inspector.stdout.on('data', (data) => {
output += data.toString();
process.stdout.write(data);
});
inspector.stderr.on('data', (data) => {
output += data.toString();
process.stderr.write(data);
});
// Wait for startup
await new Promise(resolve => setTimeout(resolve, 5000));
// Check for SSE connection issues in output
if (output.includes('SSE connection closed')) {
console.log('\n❌ SSE connection issues detected during test');
} else {
console.log('\n✅ No immediate SSE connection issues detected');
}
// Cleanup
inspector.kill('SIGTERM');
setTimeout(() => {
if (!inspector.killed) {
inspector.kill('SIGKILL');
}
}, 2000);
}
async runComplete() {
await this.runDiagnostics();
if (this.fixes.length > 0) {
console.log('\n🔧 Fixes recommended. Run with --fix to apply them.');
}
console.log('\n📋 Available commands:');
console.log(' --diagnose : Run diagnostics only');
console.log(' --fix : Apply recommended fixes');
console.log(' --monitor : Start connection monitoring');
console.log(' --test : Test connection stability');
}
generateRecommendations() {
console.log('\n📋 Recommendations:');
if (this.fixes.length === 0) {
console.log('✅ No immediate issues detected');
console.log('ℹ️ If you\'re still experiencing SSE connection issues:');
console.log(' 1. Run: node scripts/fix-sse-connection-issues.js --monitor');
console.log(' 2. Check browser console for client-side errors');
console.log(' 3. Verify network connectivity and firewall settings');
} else {
console.log('⚠️ Issues detected that may cause SSE connection problems:');
this.fixes.forEach(fix => {
console.log(` - ${fix}`);
});
console.log('\n🔧 Run with --fix to apply recommended fixes');
}
}
// Utility methods
readPackageJson() {
try {
return JSON.parse(fs.readFileSync(path.join(this.projectRoot, 'package.json'), 'utf8'));
} catch (error) {
return {};
}
}
compareVersions(version1, version2) {
const v1 = version1.replace('v', '').split('.').map(Number);
const v2 = version2.replace('v', '').split('.').map(Number);
for (let i = 0; i < Math.max(v1.length, v2.length); i++) {
const a = v1[i] || 0;
const b = v2[i] || 0;
if (a > b) return 1;
if (a < b) return -1;
}
return 0;
}
execCommand(command) {
return new Promise((resolve, reject) => {
exec(command, (error, stdout, stderr) => {
if (error) {
reject(error);
} else {
resolve({ stdout, stderr });
}
});
});
}
}
// Run the fixer
if (import.meta.url === `file://${process.argv[1]}`) {
const fixer = new SSEConnectionFixer();
fixer.run().catch(error => {
console.error('❌ Error running SSE connection fixer:', error);
process.exit(1);
});
}
export default SSEConnectionFixer;
