multi-node.ts

/**
 * Multi-Node Example
 * 
 * This example demonstrates how to configure SessionPool to work with
 * multiple IoTDB nodes for load balancing using the new nodeUrls API.
 */

import { SessionPool, PoolConfigBuilder } from '../src';

async function main() {
 console.log('=== Multi-Node Example ===\n');

 // Method 1: Using nodeUrls with string array format (RECOMMENDED)
 console.log('Method 1: Using nodeUrls in string array format (host:port)');
 const pool1 = new SessionPool({
 nodeUrls: [
 'node1.example.com:6667',
 'node2.example.com:6668',
 'node3.example.com:6669',
 ],
 username: 'root',
 password: 'root',
 maxPoolSize: 15, // 5 connections per node
 minPoolSize: 3, // 1 connection per node initially
 });

 // Method 2: Using Builder pattern with string array format (RECOMMENDED)
 console.log('Method 2: Using Builder pattern with string array');
 const pool2 = new SessionPool(
 new PoolConfigBuilder()
 .nodeUrls([
 'node1.example.com:6667',
 'node2.example.com:6668',
 'node3.example.com:6669',
 ])
 .username('root')
 .password('root')
 .maxPoolSize(15)
 .minPoolSize(3)
 .build()
 );

 // Method 3: Using nodeUrls with object format (also supported)
 console.log('Method 3: Using nodeUrls in object format');
 const pool3 = new SessionPool({
 nodeUrls: [
 { host: 'node1.example.com', port: 6667 },
 { host: 'node2.example.com', port: 6668 },
 { host: 'node3.example.com', port: 6669 },
 ],
 username: 'root',
 password: 'root',
 maxPoolSize: 15,
 minPoolSize: 3,
 });

 // Method 4: Backward compatible - same port for all hosts
 console.log('Method 4: Backward compatible (same port for all hosts)');
 const pool4 = new SessionPool(
 [
 'node1.example.com',
 'node2.example.com',
 'node3.example.com',
 ],
 6667,
 {
 username: 'root',
 password: 'root',
 maxPoolSize: 15,
 minPoolSize: 3,
 }
 );

 // For demo purposes, we'll use pool1
 const pool = pool1;

 try {
 console.log('\nInitializing multi-node session pool...');
 await pool.init();
 console.log('Pool initialized with', pool.getPoolSize(), 'connections across 3 nodes');

 // Execute operations
 // Connections will be distributed across all nodes using round-robin
 console.log('\nExecuting operations across nodes...');
 
 for (let i = 0; i < 10; i++) {
 const dataSet = await pool.executeQueryStatement('SHOW DATABASES');
 let count = 0;
 while (await dataSet.hasNext()) {
 dataSet.next();
 count++;
 }
 await dataSet.close();
 console.log(`Query ${i + 1} executed (result count: ${count})`);
 }

 console.log('\nAll operations completed');
 console.log('Final pool size:', pool.getPoolSize());
 console.log('Available connections:', pool.getAvailableSize());

 } catch (error) {
 console.error('Error:', error);
 } finally {
 await pool.close();
 console.log('Pool closed');
 }
}

main().catch(console.error);