pool failure

/*
 *  SQL & Node.JS test program
 *  Joseph Burger
 *
 *  Notes:
 *  According to documentation @ "https://github.com/felixge/node-mysql#terminating-connections",
 *  I should call pool.end(). However if I do, the rest of the program doesn't run, and the program
 *  also hangs on the command line - unacceptable.
 *
 *  After hours, I arrived at this solution: rather than call connection.release() as the documentation
 *  recommended, I call destroy (and not end() either). Additionally I don't call connection.release().
 *
 *  It's probably a bad answer to the problem but at least it works.
 *
 *  A bigger question is how the heck do I get results back from these asynchronous callbacks?
 *  Sure, I can call functions from within callbacks. But that requires me to plan my programming
 *  around that. Ugh.
 *
 */
var mysql      = require('mysql');
var pool = mysql.createPool({
    host     : 'localhost',
    user     : '*******',
    password : '*******',
    database : 'users',
});

var fns = ["lina", "lanna", "cheryl", "heinrick", "bob", "larry", "william", "alice", "stewey", "jiang"],
    lns = ["anderson", "bojangles", "williamson", "polerson", "dottson", "bjarnes", "gandertronf"];

var post = { username: fns[Math.floor(Math.random() * fns.length)],
             password: lns[Math.floor(Math.random() * lns.length)] }
function complex()
{
    pool.getConnection(function(err, connection)
    {
        console.log("Inserting: " + post.username + "\t" + post.password);
        connection.query('insert into `user_info` SET ?', post,
             function(err, result) {
                  if (err) console.log (err);
                  connection.destroy();
                  getNum(); // +=+=+=+=+=
                  console.log("\t\t-!-!- Exiting complex()");
              });
    });
}

function getNum()
{
    pool.getConnection(function(err, connection){
        connection.query('select * from `user_info`', function (error, rows, fields) {
            if (error) throw error;

            ident = rows[Math.floor(Math.random() * rows.length)].ID;
            console.log("Number of rows:\t" + rows.length);
            console.log("ID to be deleted:\t" + ident);
            connection.destroy();
            del(ident); // +=+=+=+=+=
            console.log("\t\t-!-!- Exiting getNum()");
        });
    });
}

function del(ident)
{
    post = ['user_info', 'id', ident];

    pool.getConnection(function(err, connection)
    {
        var query = connection.query('DELETE FROM ?? WHERE ?? = ?', post, function(err, result)
        {
            if (err) throw err;
            console.log('deleted ' + result.affectedRows + ' rows');
            connection.destroy();
            console.log("\t\t-!-!- Exiting del()");
        });
        console.log(query.sql);
    });
}

complex(); // +=+=+=+=+=

console.log("Heya bud! It's over!");

//pool.end();

// Output:
/*
Heya bud! It's over!
Inserting: lina polerson
        -!-!- Exiting complex()
Number of rows: 72
ID to be deleted:   2
        -!-!- Exiting getNum()
DELETE FROM `user_info` WHERE `id` = 2
deleted 1 rows
        -!-!- Exiting del()
*/