AWS Lambda: Reusing database connections

index.js

const Redis = require('ioredis');
const redis = new Redis();

exports.handler = (event, context, callback) => {
    context.callbackWaitsForEmptyEventLoop = false;

    redis.pipeline()
        .set('a', 'b')
        .get('a')
        .exec()
        .then(response => callback(null, response))
        .catch(err => callback(err));
};