AWS RDS MySQL Connection count - mysql

Question

I have a simple program that connects to an AWS MySQL DB via Lambda.
Every request from the app is basically a single query on the database. So if I have 3 users using the app, it would be impossible for more than 3 queries to be run on the database at the same time.
Yet when I look at my connection count it could be as high as 15. I've been having trouble understanding exactly how this should work.
If the code is written correctly does that mean if there's 3 users at once, I shouldn't have more than 3 connections?
I've been trying to find a basic article to explain this but obviously haven't hence I'm here.
Thank you.
EDITED TO ADD CODE
Below is a cut down version of my code
var mysql = require('mysql');
var pool =[];
exports.handler = (event, context, callback) => {
context.callbackWaitsForEmptyEventLoop = false;
pool = mysql.createPool({
host : 'host-details',
user : 'username',
password : 'password',
database : 'db'
});
return myFunc(event, context, callback, data.Username);
}
};
const myFunc = async (event, context, callback) => {
const query = 'SELECT * from db.table';
const data = await dbQueryAsyncWL(context, callback, query);
return callback(null, {data: data});
}
const dbQueryAsyncWL = async (context, callback, query) => {
return new Promise((resolve) => {
context.callbackWaitsForEmptyEventLoop = false;
pool.getConnection(function(error, connection) {
connection.query(query, function (error, results, fields) {
connection.release();
if (error) {callback(error);} else {resolve(results);}
});
});
})
}

Answer 1

pool = mysql.createPool({
host : 'host-details',
user : 'username',
password : 'password',
database : 'db'
});
Check the size / minimum size of the connection pool.
What is the connection pool configuration, like idleTime etc before closing a connection.
What trends are you noticing around the size of connection pool, is it stable or increase/decreasing ?

Answer 2

Looks like my issue was that I was creating the pool inside the exports.handler. Once I moved it outside... well a picture says it all.
https://i.ibb.co/KDvfdhp/Screen-Shot-2020-06-29-at-10-26-49-pm.png