Health Monitoring & Auto-Recovery Guide

⚠️ PLANNED FEATURE: This documentation describes features that are planned but not yet implemented. The HealthMonitor class referenced in this guide does not currently exist in the codebase. The code examples are illustrative of the intended API design.

NeuroLink Enhanced MCP Platform - Health Monitoring

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🏥 Overview: Connection Health Management

The NeuroLink MCP platform includes sophisticated health monitoring that provides real-time connection status tracking, automatic failure detection, and intelligent recovery mechanisms for all MCP servers.

Key Features

• 6-State Connection Lifecycle: Complete connection status management
• Periodic Health Checks: Configurable monitoring with latency tracking
• Auto-Recovery Logic: Exponential backoff with intelligent retry strategies
• Event-Driven Architecture: Real-time status notifications
• Performance Monitoring: Health metrics and trend analysis

---

🏗️ Architecture & Components

Connection Status States

export enum ConnectionStatus {
  DISCONNECTED = "DISCONNECTED", // No connection established
  CONNECTING = "CONNECTING", // Connection attempt in progress
  CONNECTED = "CONNECTED", // Successfully connected and operational
  CHECKING = "CHECKING", // Health check in progress
  ERROR = "ERROR", // Connection error detected
  RECOVERING = "RECOVERING", // Auto-recovery in progress
}

Health Monitor Core

export class HealthMonitor extends EventEmitter {
  private healthCheckTimers: Map<string, NodeJS.Timeout> = new Map();
  private serverStatus: Map<string, ServerHealth> = new Map();
  private recoveryAttempts: Map<string, number> = new Map();

  async startHealthMonitoring(registry: MCPRegistry): Promise<void> {
    const servers = await registry.listServers();

    for (const serverId of servers) {
      await this.initializeServerMonitoring(serverId);
    }

    this.emit("monitoring-started", { serverCount: servers.length });
  }

  async performHealthCheck(serverId: string): Promise<HealthCheckResult> {
    const startTime = Date.now();

    try {
      this.updateServerStatus(serverId, ConnectionStatus.CHECKING);

      const server = await this.registry.getServer(serverId);
      await server.ping(); // Custom ping implementation

      const result: HealthCheckResult = {
        success: true,
        status: ConnectionStatus.CONNECTED,
        latency: Date.now() - startTime,
        timestamp: Date.now(),
      };

      this.updateServerStatus(serverId, ConnectionStatus.CONNECTED);
      this.emit("health-check-success", { serverId, result });

      return result;
    } catch (error) {
      const result: HealthCheckResult = {
        success: false,
        status: ConnectionStatus.ERROR,
        error: error as Error,
        timestamp: Date.now(),
      };

      this.updateServerStatus(serverId, ConnectionStatus.ERROR);
      this.emit("health-check-failed", { serverId, result });

      // Trigger auto-recovery
      await this.attemptRecovery(serverId);

      return result;
    }
  }
}

Health Check Interface

export type HealthCheckResult = {
  success: boolean;
  status: ConnectionStatus;
  message?: string;
  latency?: number;
  error?: Error;
  timestamp: number;
  metadata?: {
    serverVersion?: string;
    capabilities?: string[];
    resourceUsage?: ResourceMetrics;
  };
};

export type ServerHealth = {
  serverId: string;
  status: ConnectionStatus;
  lastHealthCheck: HealthCheckResult;
  healthHistory: HealthCheckResult[];
  recoveryAttempts: number;
  uptime: number;
  lastSuccessfulConnection: number;
};

---

🔄 Auto-Recovery Mechanisms

Intelligent Recovery Logic

export class RecoveryManager {
  private maxRecoveryAttempts: number = 3;
  private baseRetryInterval: number = 5000; // 5 seconds
  private maxRetryInterval: number = 60000; // 1 minute

  async attemptRecovery(serverId: string): Promise<boolean> {
    const attempts = this.recoveryAttempts.get(serverId) || 0;

    if (attempts >= this.maxRecoveryAttempts) {
      console.warn(`Max recovery attempts reached for server ${serverId}`);
      this.emit("recovery-failed", { serverId, attempts });
      return false;
    }

    this.updateServerStatus(serverId, ConnectionStatus.RECOVERING);
    this.recoveryAttempts.set(serverId, attempts + 1);

    // Exponential backoff with jitter
    const delay =
      Math.min(
        this.baseRetryInterval * Math.pow(2, attempts),
        this.maxRetryInterval,
      ) +
      Math.random() * 1000; // Add jitter

    await new Promise((resolve) => setTimeout(resolve, delay));

    try {
      await this.reconnectServer(serverId);

      // Reset recovery attempts on success
      this.recoveryAttempts.delete(serverId);
      this.updateServerStatus(serverId, ConnectionStatus.CONNECTED);

      this.emit("recovery-success", { serverId, attempts: attempts + 1 });
      return true;
    } catch (error) {
      console.error(
        `Recovery attempt ${attempts + 1} failed for ${serverId}:`,
        error,
      );

      // Schedule next recovery attempt
      setTimeout(() => {
        this.attemptRecovery(serverId);
      }, delay);

      return false;
    }
  }
}

Connection Lifecycle Management

// State transition logic
const connectionLifecycle = {
  async connect(serverId: string): Promise<void> {
    this.updateStatus(serverId, ConnectionStatus.CONNECTING);

    try {
      await this.establishConnection(serverId);
      this.updateStatus(serverId, ConnectionStatus.CONNECTED);
      this.startPeriodicHealthChecks(serverId);
    } catch (error) {
      this.updateStatus(serverId, ConnectionStatus.ERROR);
      await this.attemptRecovery(serverId);
    }
  },

  async disconnect(serverId: string): Promise<void> {
    this.stopHealthChecks(serverId);
    await this.closeConnection(serverId);
    this.updateStatus(serverId, ConnectionStatus.DISCONNECTED);
  },
};

---

🚀 Usage Examples

Basic Health Monitoring Setup

import { HealthMonitor } from "@juspay/neurolink";

// Initialize health monitor
const healthMonitor = new HealthMonitor({
  healthCheckInterval: 30000, // 30 seconds
  recoveryRetryInterval: 5000, // 5 seconds
  maxRecoveryAttempts: 3,
  enableEventLogging: true,
});

// Start monitoring all servers
await healthMonitor.startHealthMonitoring(mcpRegistry);

// Listen for health events
healthMonitor.on("health-check-failed", ({ serverId, result }) => {
  console.warn(`Health check failed for ${serverId}:`, result.error?.message);
});

healthMonitor.on("recovery-success", ({ serverId, attempts }) => {
  console.log(`Server ${serverId} recovered after ${attempts} attempts`);
});

Custom Health Check Implementation

// Implement custom health checks
class CustomHealthMonitor extends HealthMonitor {
  async performAdvancedHealthCheck(
    serverId: string,
  ): Promise<HealthCheckResult> {
    const startTime = Date.now();

    try {
      const server = await this.registry.getServer(serverId);

      // Basic connectivity check
      await server.ping();

      // Advanced checks
      const capabilities = await server.listCapabilities();
      const resourceUsage = await server.getResourceUsage();
      const version = await server.getVersion();

      return {
        success: true,
        status: ConnectionStatus.CONNECTED,
        latency: Date.now() - startTime,
        timestamp: Date.now(),
        metadata: {
          serverVersion: version,
          capabilities: capabilities,
          resourceUsage: resourceUsage,
        },
      };
    } catch (error) {
      return {
        success: false,
        status: ConnectionStatus.ERROR,
        error: error as Error,
        timestamp: Date.now(),
      };
    }
  }
}

Health-Aware Tool Execution

// Execute tools with health awareness
const healthAwareExecution = async (
  toolName: string,
  args: any,
  context: any,
) => {
  const serverId = await registry.getServerForTool(toolName);
  const serverHealth = await healthMonitor.getServerHealth(serverId);

  if (serverHealth.status !== ConnectionStatus.CONNECTED) {
    // Try to recover connection first
    const recovered = await healthMonitor.attemptRecovery(serverId);

    if (!recovered) {
      throw new Error(`Server ${serverId} is unavailable for tool ${toolName}`);
    }
  }

  // Execute tool with health monitoring
  try {
    const result = await registry.executeTool(toolName, args, context);

    // Update health status on successful execution
    healthMonitor.recordSuccessfulOperation(serverId);

    return result;
  } catch (error) {
    // Report health issue on tool execution failure
    healthMonitor.recordFailedOperation(serverId, error);
    throw error;
  }
};

---

📊 Health Analytics & Monitoring

Health Metrics Collection

type HealthMetrics = {
  serverCount: number;
  healthyServers: number;
  unhealthyServers: number;
  recoveringServers: number;
  averageLatency: number;
  uptimePercentage: number;
  totalHealthChecks: number;
  failedHealthChecks: number;
  successfulRecoveries: number;
  failedRecoveries: number;
};

export class HealthAnalytics {
  async collectHealthMetrics(): Promise<HealthMetrics> {
    const allServers = await this.healthMonitor.getAllServerHealth();
    const now = Date.now();

    const healthyServers = allServers.filter(
      (s) => s.status === ConnectionStatus.CONNECTED,
    ).length;
    const unhealthyServers = allServers.filter(
      (s) => s.status === ConnectionStatus.ERROR,
    ).length;
    const recoveringServers = allServers.filter(
      (s) => s.status === ConnectionStatus.RECOVERING,
    ).length;

    const totalLatency = allServers.reduce((sum, server) => {
      return sum + (server.lastHealthCheck.latency || 0);
    }, 0);

    const uptimePercentage =
      allServers.reduce((sum, server) => {
        const uptime =
          (now - server.lastSuccessfulConnection) / (now - server.createdAt);
        return sum + Math.max(0, Math.min(1, uptime));
      }, 0) / allServers.length;

    return {
      serverCount: allServers.length,
      healthyServers,
      unhealthyServers,
      recoveringServers,
      averageLatency: totalLatency / allServers.length,
      uptimePercentage,
      totalHealthChecks: this.getTotalHealthChecks(),
      failedHealthChecks: this.getFailedHealthChecks(),
      successfulRecoveries: this.getSuccessfulRecoveries(),
      failedRecoveries: this.getFailedRecoveries(),
    };
  }
}

Real-time Health Dashboard

// Real-time health monitoring dashboard
export class HealthDashboard {
  private metrics: HealthMetrics;
  private updateInterval: NodeJS.Timeout;

  start(): void {
    this.updateInterval = setInterval(async () => {
      await this.updateDashboard();
    }, 5000); // Update every 5 seconds
  }

  private async updateDashboard(): Promise<void> {
    this.metrics = await this.healthAnalytics.collectHealthMetrics();

    console.clear();
    console.log("=== NeuroLink MCP Health Dashboard ===");
    console.log(
      `Servers: ${this.metrics.healthyServers}/${this.metrics.serverCount} healthy`,
    );
    console.log(`Average Latency: ${this.metrics.averageLatency.toFixed(2)}ms`);
    console.log(`Uptime: ${(this.metrics.uptimePercentage * 100).toFixed(2)}%`);
    console.log(
      `Recovery Success Rate: ${this.getRecoverySuccessRate().toFixed(2)}%`,
    );

    // Display server status
    const serverHealth = await this.healthMonitor.getAllServerHealth();
    console.log("\nServer Status:");
    serverHealth.forEach((server) => {
      const statusIcon = this.getStatusIcon(server.status);
      const latency = server.lastHealthCheck.latency || 0;
      console.log(
        `  ${statusIcon} ${server.serverId}: ${server.status} (${latency}ms)`,
      );
    });
  }

  private getStatusIcon(status: ConnectionStatus): string {
    switch (status) {
      case ConnectionStatus.CONNECTED:
        return "🟢";
      case ConnectionStatus.CONNECTING:
        return "🟡";
      case ConnectionStatus.CHECKING:
        return "🔵";
      case ConnectionStatus.RECOVERING:
        return "🟠";
      case ConnectionStatus.ERROR:
        return "🔴";
      case ConnectionStatus.DISCONNECTED:
        return "⚫";
      default:
        return "❓";
    }
  }
}

---

🧪 Testing & Validation

Health Check Testing

// Test health monitoring functionality
const testHealthMonitoring = async () => {
  console.log("=== Testing Health Monitoring ===");

  // Test basic health check
  const result = await healthMonitor.performHealthCheck("test-server");
  console.log("Health check result:", result);

  // Test recovery mechanism
  console.log("Testing recovery mechanism...");
  await healthMonitor.simulateServerFailure("test-server");

  // Wait for auto-recovery
  await new Promise((resolve) => {
    healthMonitor.once("recovery-success", () => {
      console.log("✅ Auto-recovery successful");
      resolve(undefined);
    });

    healthMonitor.once("recovery-failed", () => {
      console.log("❌ Auto-recovery failed");
      resolve(undefined);
    });
  });
};

Performance Testing

// Test health monitoring performance
const testHealthPerformance = async () => {
  const serverCount = 50;
  const healthCheckCount = 100;

  console.log(`Testing health checks for ${serverCount} servers...`);

  const startTime = Date.now();
  const promises = [];

  for (let i = 0; i < serverCount; i++) {
    for (let j = 0; j < healthCheckCount; j++) {
      promises.push(healthMonitor.performHealthCheck(`server-${i}`));
    }
  }

  const results = await Promise.all(promises);
  const duration = Date.now() - startTime;

  const successCount = results.filter((r) => r.success).length;
  const averageLatency =
    results.reduce((sum, r) => sum + (r.latency || 0), 0) / results.length;

  console.log("Performance Results:");
  console.log(`- Total checks: ${results.length}`);
  console.log(
    `- Success rate: ${((successCount / results.length) * 100).toFixed(2)}%`,
  );
  console.log(`- Average latency: ${averageLatency.toFixed(2)}ms`);
  console.log(`- Total duration: ${duration}ms`);
  console.log(
    `- Checks per second: ${((results.length / duration) * 1000).toFixed(2)}`,
  );
};

---

🔧 Configuration & Customization

Advanced Configuration

type HealthMonitorConfig = {
  intervals: {
    healthCheck: number; // Health check interval (ms)
    recovery: number; // Recovery retry interval (ms)
    cleanup: number; // Cleanup interval for old data (ms)
  };
  thresholds: {
    maxRecoveryAttempts: number; // Max recovery attempts before giving up
    maxLatency: number; // Max acceptable latency (ms)
    minUptime: number; // Minimum uptime percentage
  };
  recovery: {
    strategy: "exponential" | "linear" | "custom";
    baseDelay: number; // Base delay for recovery attempts
    maxDelay: number; // Maximum delay between attempts
    jitter: boolean; // Add random jitter to delays
  };
  alerting: {
    enableAlerts: boolean; // Enable health alerts
    alertThresholds: {
      consecutiveFailures: number; // Alert after N consecutive failures
      uptimeBelow: number; // Alert when uptime drops below percentage
      latencyAbove: number; // Alert when latency exceeds threshold
    };
  };
};

const healthMonitor = new HealthMonitor({
  intervals: {
    healthCheck: 30000, // 30 seconds
    recovery: 5000, // 5 seconds
    cleanup: 3600000, // 1 hour
  },
  thresholds: {
    maxRecoveryAttempts: 5,
    maxLatency: 5000, // 5 seconds
    minUptime: 0.95, // 95%
  },
  recovery: {
    strategy: "exponential",
    baseDelay: 1000, // 1 second
    maxDelay: 60000, // 1 minute
    jitter: true,
  },
  alerting: {
    enableAlerts: true,
    alertThresholds: {
      consecutiveFailures: 3,
      uptimeBelow: 0.9, // 90%
      latencyAbove: 3000, // 3 seconds
    },
  },
});

---

🎯 Best Practices

Monitoring Strategy

// Implement tiered monitoring
const tieredMonitoring = {
  // Critical servers: frequent monitoring
  critical: {
    interval: 15000, // 15 seconds
    maxLatency: 1000, // 1 second
    immediateRecovery: true,
  },

  // Important servers: standard monitoring
  important: {
    interval: 30000, // 30 seconds
    maxLatency: 3000, // 3 seconds
    recoveryDelay: 5000, // 5 seconds
  },

  // Background servers: light monitoring
  background: {
    interval: 60000, // 1 minute
    maxLatency: 10000, // 10 seconds
    recoveryDelay: 30000, // 30 seconds
  },
};

Resource Optimization

// Optimize health monitoring resources
const optimizeMonitoring = {
  // Batch health checks
  async batchHealthChecks(serverIds: string[]): Promise<HealthCheckResult[]> {
    const batchSize = 10;
    const results: HealthCheckResult[] = [];

    for (let i = 0; i < serverIds.length; i += batchSize) {
      const batch = serverIds.slice(i, i + batchSize);
      const batchResults = await Promise.all(
        batch.map((id) => this.performHealthCheck(id)),
      );
      results.push(...batchResults);
    }

    return results;
  },

  // Adaptive monitoring intervals
  adjustMonitoringInterval(
    serverId: string,
    healthHistory: HealthCheckResult[],
  ): number {
    const recentFailures = healthHistory
      .slice(-5)
      .filter((h) => !h.success).length;
    const baseInterval = 30000;

    if (recentFailures === 0) {
      return baseInterval * 2; // Healthy servers need less frequent checks
    } else if (recentFailures >= 3) {
      return baseInterval / 2; // Unhealthy servers need more frequent checks
    }

    return baseInterval;
  },
};

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STATUS: Planned health monitoring system (not yet implemented)