pooling.js

#!/usr/bin/env node

const { Sema } = require('async-sema');
const redis = require('promise-redis');

async function f() {
	const red = new Sema(3, {
		initFn: () => redis().createClient(process.env.REDIS_URL)
	});

	const db = await red.acquire();
	console.log(await db.get('id'));
	red.release(db);

	const dbs = await red.drain();
	dbs.map(db => db.quit());
}
f()
	.catch(e => console.log(e))
	.then(() => console.log('READY'));