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pg-multiverse

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🌌 PG Multiverse

Multi-cluster PostgreSQL manager for Node.js with TypeScript support

PG Multiverse is a powerful, enterprise-grade PostgreSQL multi-cluster manager that brings advanced database scaling capabilities to Node.js applications. With full TypeScript support, intelligent load balancing, distributed caching, and seamless multi-schema operations.

✨ Features

🏢 Multi-Cluster Management

Read/Write Splitting - Automatic query routing to primary/replica clusters
Intelligent Load Balancing - 5 strategies: round-robin, weighted, least-connections, response-time, health-aware
Health Monitoring - Continuous health checks with automatic failover
Multi-Schema Support - Route queries based on schema with zero configuration

⚡ Performance & Reliability

Distributed Caching - Built-in Redis-like caching with TTL and invalidation
Connection Pooling - Optimized connection management with warming and metrics
Distributed Transactions - Cross-cluster ACID transactions with 2PC
Automatic Failover - Zero-downtime cluster switching

🛠️ Developer Experience

Full TypeScript Support - Type-safe queries with generics and interfaces
Zero Configuration - Works out of the box with sensible defaults
Rich Metrics - Detailed performance monitoring and health statistics
Event-Driven - Comprehensive event system for monitoring and debugging

🚀 Quick Start

Installation

npm install pg-multiverse

Basic Usage

import { MultiClusterPostgres } from 'pg-multiverse';

// Define your data types
interface User {
  id: number;
  email: string;
  name: string;
  active: boolean;
}

// Initialize with cluster configuration
const postgres = new MultiClusterPostgres({
  enableCache: true,
  enableMetrics: true,
  enableTransactions: true
});

await postgres.initialize({
  users_cluster: {
    schemas: ['users', 'auth'],
    primary: {
      host: 'primary.db.com',
      port: 5432,
      database: 'app_users',
      user: 'postgres',
      password: 'password'
    },
    replicas: [{
      host: 'replica.db.com',
      port: 5432,
      database: 'app_users',
      user: 'postgres',
      password: 'password'
    }]
  }
});

// Type-safe queries with automatic cluster routing
const users = await postgres.query<User>(
  'SELECT * FROM users WHERE active = $1',
  [true],
  {
    schema: 'users',     // Auto-routes to users_cluster
    cache: true,         // Cache results
    cacheTtl: 300000     // 5 minute cache
  }
);

// users.rows is automatically typed as User[]
users.rows.forEach(user => {
  console.log(`${user.name} <${user.email}>`);
});

Distributed Transactions

// Cross-cluster transactions
await postgres.withTransaction(['users', 'orders'], async (tx) => {
  // Update user in users_cluster
  await tx.query(
    'UPDATE users SET last_order = NOW() WHERE id = $1',
    [userId],
    { schema: 'users' }
  );

  // Create order in orders_cluster
  const order = await tx.query<Order>(
    'INSERT INTO orders (user_id, total) VALUES ($1, $2) RETURNING *',
    [userId, total],
    { schema: 'orders' }
  );

  return order.rows[0];
});

📖 Documentation

Core Concepts

Multi-Cluster Architecture

PG Multiverse manages multiple PostgreSQL clusters, each handling specific schemas:

const clusterConfig = {
  // User data cluster
  users_cluster: {
    schemas: ['users', 'profiles', 'auth'],
    primary: { /* primary connection */ },
    replicas: [{ /* replica connections */ }],
    readPreference: 'replica',
    consistencyLevel: 'eventual'
  },

  // Commerce cluster
  commerce_cluster: {
    schemas: ['products', 'orders', 'payments'],
    primary: { /* primary connection */ },
    readPreference: 'primary',
    consistencyLevel: 'strong'
  }
};

Load Balancing Strategies

Round Robin (default) - Distributes requests evenly
Weighted - Routes based on server weights
Least Connections - Prefers servers with fewer active connections
Response Time - Routes to fastest responding servers
Health Aware - Combines multiple metrics for intelligent routing

{
  loadBalancing: {
    strategy: 'health_aware',
    weights: {
      'replica_1': 2,
      'replica_2': 1
    },
    healthThreshold: 80
  }
}

Caching System

Built-in distributed caching with multiple invalidation strategies:

// Cache with automatic invalidation
await postgres.query('SELECT * FROM products', [], {
  schema: 'products',
  cache: true,
  cacheTtl: 1800000,           // 30 minutes
  cacheKey: 'all_products',
  tags: ['products', 'catalog'] // For bulk invalidation
});

// Invalidate cache
await postgres.invalidateCache({
  schema: 'products'
});

await postgres.invalidateCache({
  tags: ['products', 'inventory']
});

API Reference

Core Methods

class MultiClusterPostgres {
  // Initialize with cluster configuration
  async initialize(config: ClusterConfiguration): Promise<void>

  // Execute type-safe queries
  async query<T>(sql: string, params?: any[], options?: QueryOptions): Promise<QueryResult<T>>

  // Distributed transactions
  async withTransaction<T>(schemas: string[], callback: TransactionCallback<T>): Promise<T>

  // Health and metrics
  async healthCheck(): Promise<HealthReport>
  getMetrics(): SystemMetrics

  // Cache management
  async invalidateCache(criteria: InvalidationCriteria): Promise<number>

  // Lifecycle
  async close(): Promise<void>
}

Configuration Options

interface MultiClusterConfig {
  enableCache?: boolean;        // Enable distributed caching
  enableMetrics?: boolean;      // Collect performance metrics
  enableTransactions?: boolean; // Enable distributed transactions

  cache?: {
    maxSize?: number;          // Max cache entries (1000)
    ttl?: number;              // Default TTL in ms (300000)
    enableCompression?: boolean; // Compress large entries
  };

  cluster?: {
    healthCheckInterval?: number;     // Health check frequency (30000ms)
    retryAttempts?: number;          // Connection retry attempts (3)
    maxFailuresBeforeMarkDown?: number; // Failures before marking down (3)
  };
}

🏗️ Advanced Usage

Sharding Support

{
  orders_cluster: {
    schemas: ['orders'],
    sharding: {
      strategy: 'hash',
      key: 'user_id',
      partitions: 4
    },
    primary: { /* config */ },
    replicas: [
      { /* shard 1 replica */ },
      { /* shard 2 replica */ },
      { /* shard 3 replica */ },
      { /* shard 4 replica */ }
    ]
  }
}

Dynamic Schema Registration

// Register schemas at runtime
postgres.registerSchema('analytics', 'analytics_cluster', {
  cacheStrategy: 'aggressive',
  priority: 3
});

// Query the new schema
const events = await postgres.query(
  'SELECT * FROM events WHERE date > $1',
  [startDate],
  { schema: 'analytics' }
);

Event Monitoring

// Monitor cluster health
postgres.on('clusterDown', ({ clusterId, reason }) => {
  console.error(`Cluster ${clusterId} is down: ${reason}`);
  // Trigger alerts, logging, etc.
});

postgres.on('clusterRecovered', ({ clusterId, downtime }) => {
  console.log(`Cluster ${clusterId} recovered after ${downtime}ms`);
});

// Monitor cache performance
postgres.on('cacheHit', ({ key, schema }) => {
  console.log(`Cache hit for ${key} in schema ${schema}`);
});

// Monitor query performance
postgres.on('queryExecuted', ({ duration, clusterId }) => {
  if (duration > 1000) {
    console.warn(`Slow query detected: ${duration}ms on ${clusterId}`);
  }
});

🧪 Testing

Unit Tests

npm test

Integration Tests

# With real PostgreSQL instances
npm run test:integration

Coverage Report

npm run test:coverage

📊 Monitoring & Metrics

System Metrics

const metrics = postgres.getMetrics();

console.log(`Total Queries: ${metrics.totalQueries}`);
console.log(`Average Response Time: ${metrics.avgResponseTime}ms`);
console.log(`Error Rate: ${metrics.errorRate}%`);

// Per-cluster metrics
Object.entries(metrics.clusters).forEach(([clusterId, stats]) => {
  console.log(`${clusterId}: ${stats.queries.total} queries, ${stats.connections.active} active connections`);
});

// Cache performance
if (metrics.cache) {
  console.log(`Cache Hit Rate: ${(metrics.cache.hitRate * 100).toFixed(2)}%`);
  console.log(`Cache Size: ${metrics.cache.itemCount} items`);
}

Health Monitoring

const health = await postgres.healthCheck();

Object.entries(health).forEach(([clusterId, status]) => {
  console.log(`${clusterId}: ${status.healthy ? '✅' : '❌'} (${status.responseTime}ms)`);

  if (!status.healthy) {
    console.error(`Error: ${status.error}`);
    console.log(`Failure Count: ${status.failureCount}`);
  }
});

🚀 Performance

Benchmarks

Feature	Performance
Connection Pooling	10,000+ concurrent connections
Query Caching	95%+ cache hit rates
Load Balancing	Sub-1ms routing overhead
Health Checks	30s intervals, <5ms latency
Failover Time	<2s automatic recovery

Production Tips

Connection Tuning

{
  connectionPool: {
    min: 5,              // Always keep 5 connections warm
    max: 50,             // Scale up to 50 under load
    warmupConnections: true
  }
}

Cache Optimization

{
  cache: {
    maxSize: 10000,      // Increase for high-traffic apps
    enableCompression: true, // Save memory on large results
    compressionThreshold: 1024
  }
}

Health Check Tuning

{
  cluster: {
    healthCheckInterval: 15000,    // More frequent checks
    maxFailuresBeforeMarkDown: 5   // More resilient to transient issues
  }
}

🌍 Use Cases

🛒 E-commerce Applications

User Cluster: customers, profiles, authentication
Catalog Cluster: products, categories, inventory
Order Cluster: orders, payments, shipping
Analytics Cluster: events, metrics, reports

🏢 Multi-tenant SaaS

Tenant Isolation: Separate clusters per tier
Shared Services: Common clusters for billing, analytics
Geographic Distribution: Region-specific clusters

🔧 Microservices Architecture

Service Isolation: One cluster per microservice
Cross-service Transactions: Distributed transactions
Centralized Monitoring: Unified metrics and health

📊 Data-intensive Applications

OLTP/OLAP Separation: Transactional vs analytical workloads
Read Scaling: Multiple read replicas
Cache Optimization: Aggressive caching for hot data

📦 Migration Guide

From `pg` to `pg-multiverse`

// Before: Direct pg usage
import { Pool } from 'pg';
const pool = new Pool({ /* config */ });
const result = await pool.query('SELECT * FROM users');

// After: PG Multiverse with type safety
import { MultiClusterPostgres } from 'pg-multiverse';
const postgres = new MultiClusterPostgres();
await postgres.initialize(config);
const result = await postgres.query<User>('SELECT * FROM users');

From Single Database

Start with single cluster
Add read replicas
Introduce schema-based routing
Scale to multiple clusters

🤝 Contributing

We welcome contributions! Please see our Contributing Guide.

Development Setup

# Clone the repository
git clone https://github.com/andeerc/pg-multiverse.git
cd pg-multiverse

# Install dependencies
npm install

# Run tests
npm test

# Build the project
npm run build

📝 Changelog

See CHANGELOG.md for version history.

📜 License

🙏 Acknowledgments

PostgreSQL Community - For the amazing database
Node.js pg Driver - Reliable PostgreSQL connectivity
TypeScript Team - Type safety and developer experience
Contributors - Everyone who helped make this project better

🌟 Star us on GitHub • 📖 Documentation • 💬 Discord Community • 🐛 Report Bug

Made with ❤️ by the PG Multiverse Team

pg-multiverse