hs2-thrift/examples/example3.js

Hive Server 2 client using Apache Thrift RPC able to query Impala for Javascript.

// const client = require("hs2-thrift");  // Use this if example.js is outside hs2-thrift package e.g. used 'npm install hs2-thrift'
const client = require("../index.js");

const config = {
	host: "example.com.au", // Change to correspond with your config
	port: 1234, // Change to correspond with your config
	username: "", // Change to correspond with your config
	password: "", // Change to correspond with your config
	protocol_ver: 5, // Version 1 - 11. Change to suit your HS2 Protocol Version, defaults to V5
	retain_session: false 	// true - will NOT close connection and session
							// false - will close connection and session
							// Default: false, connection and session will close unless specified
};

var sqlQuery = "select * from default.temp"; // Change this query to suit your db/table

function getSession(config) {
	return new Promise((resolve, reject) => {
		console.log(
			"Attempting to connect to: " + config.host + ":" + config.port
		);
		client
			.connect(config)
			.then(session => {
				resolve(session);
			})
			.catch(error => {
				reject(error);
			});
	});
}

function endSession(session) {
	return new Promise((resolve, reject) => {
		console.log("Attempting to disconnect from server and close session.");
		client
			.disconnect(session)
			.then(response => {
				resolve(response);
			})
			.catch(error => {
				reject(error);
			});
	});
}

function sendQuery(session) {
	return new Promise((resolve, reject) => {
		console.log("Sending query: " + sqlQuery);
		client
			.query(session, sqlQuery)
			.then(result => {
				resolve(result);
			})
			.catch(error => {
				reject(error);
			});
	});
}

async function queryImpala() {
	try {
		const session = await getSession(config);
		console.log("Session created.");
		const result = await sendQuery(session);
		console.log("Result: " + sqlQuery + " => \n" + JSON.stringify(result));
		const response = await endSession(session);
		console.log(
			"Disconnected from server and closed session successfully. " +
				JSON.stringify(response)
		);
		process.exit(0);
	} catch (error) {
		console.log(JSON.stringify(error));
	}
}
queryImpala();