AWS Lambda: Redis ElastiCache connection timeout error

I have a lambda function using Node 12.

I need to add a new connection to a Redis database hosted in AWS ElastiCache.

Both are in one private VPC and the security groups/subnets are configured properly.

Solution:

globals.js:

const redis = require('redis');
const redisClient = redis.createClient(
  `redis://${process.env.REDIS_HOST}:${process.env.REDIS_PORT}/${process.env.REDIS_DB}`,
);
redisClient.on('error', (err) => {
  console.log('REDIS CLIENT ERROR:' + err);
});
module.exports.globals = {
  REDIS: require('../helpers/redis')(redisClient),
};

index.js (outside handler):

const { globals } = require('./config/globals');
global.app = globals;

const lambda_handler = (event, context, callback) => { ... }
exports.handler = lambda_handler;

helpers/redis/index.js:

const get = require('./get');
module.exports = (redisClient) => {
  return {
    get:  get(redisClient)
  };
};

helpers/redis/get.js:

module.exports = (redisClient) => {
  return (key, cb) => {
    redisClient.get(key, (err, reply) => {
      if (err) {
        cb(err);
      } else {
        cb(null, reply);
      }
    });
  };
};

Function call:

app.REDIS.get(redisKey, (err, reply) => {
  console.log(`REDIS GET: ${err} ${reply}`);
});

Problem: When increasing lambda timeout to a value greater than Redis timeout, I get this error:

REDIS CLIENT ERROR:Error: Redis connection to ... failed - connect ETIMEDOUT ...

Addition:

I tried quiting/closing the connection after each transaction:

module.exports = (redisClient) => {

  return (cb) => {

    redisClient.quit((err, reply) => {
      if (err) {
        cb(err);
      } else {
        cb(null, reply);
      }
    });
  };
};

app.REDIS.get(redisKey, (err, reply) => {
  console.log(`REDIS GET: ${err} ${reply}`);
  if (err) {
    cb(err);
  } else {
    if (reply) {
      app.REDIS.quit(() => {
        cb()
      });
    }
  }
})

Error:

REDIS GET: AbortError: GET can't be processed. The connection is already closed.

Extra Notes:

• I have to use callbacks, this is why I pass ones in the above examples
• I'm using "redis": "^3.0.2"
• It's not a configuration issue as the cache was accessed hundred of times in a small period of time but it then started giving the timeout errors.
• Everything works normally locally