Long story short: one thing we did today was thinking what would be best language/framework to build an API: it should be stable under heavy load, fast, and capable of cpu-intensive operations; we ended up with 2 alternatives: PHP5 and Node.js and decided to do a little benchmarking to find out which one would be the best.

For the first test, we set up a server with virtual machines of Apache + PHP5 and another with Express + Node.js and used Siege, a stress tester, to benchmark both servers. Siege creates several connections and produces some statistics, such as number of hits, Mb transferred, transaction rate, etc. For both servers, we used 4 combinations of settings:

1. 1 core and 1,000 concurrent users
2. 4 cores and 1,500 concurrent users
3. 1 core and 1,500 concurrent users
4. 4 cores and 1,500 concurrent users

The tests consisted in a very simple task: receive the request of the user, perform a SELECT query in a database, and return the raw results back - we tried to keep the tests as similar as possible. The database used was PostgreSQL, located in another virtual machine.

These are the source codes we used for the tests:

// JavaScript
var express = require('express');
var pg = require('pg');

var config = {
  user: 'postgres',
  database: '...',
  password: '...',
  host: '...',
  max: 10,
  idleTimeoutMillis: 30000
};

var app = express();
var pool = new pg.Pool(config);

var query = 'SELECT * FROM testtable;';

function siege(req, res, next) {
    pool.connect(function (err, client, done) {
        if (err) throw err;

        client.query(query, function (err, result) {
            done();
            if (err) throw err;
            res.json(result.rows);
        });
    });
}

app.get('/siege', siege);

app.listen(3000, function () {
  console.log('Example app listening on port 3000!');
});

// php
$connection = pg_connect("host=... dbname=... user=... password=...");
$result = pg_query($connection, "SELECT * FROM testtable");
echo $result;
pg_close($connection);

These are the results:

• Aborted (too many errors)

I really was expecting the opposite result, Node.js seems to be incredibly fast in comparison to PHP for these operations.

For the next test, we tried to focus on cpu-intensive operations by running the following algorithm that searches for the first N prime numbers (yes, they could be optimized, but the purpose of the test was to make them cpu-intensive):

// JavaScript
var express = require('express');
var app = express();

app.get('/', function (req, res) {
    function isPrime(num) {
        for (var i = 2; i < num; i++) {
            if (num % i === 0) { return false; }
        }
        return true;
    }

    function display(n) {
        var count = 0;
        for (var i = 3; i < n; i += 2) {
            if (isPrime(i)) { count++; }
        }
        console.log(count);
    }
    display(70000);
    res.json({});
});

app.listen(3000, function () {
  console.log('Example app listening on port 3000!');
});

// php
function isPrime($num) {
    for ($i = 2; $i < $num; $i++) {
        if ($num % $i === 0) { return false; }
    }
    return true;
}

function display($n) {
    $count = 0;
    for ($i = 3; $i < $n; $i += 2) {
        if (isPrime($i)) { $count++; }
    }
    echo $count;
}

display(70000);

My expectations were that PHP would perform much better for this kind of tasks. These were the results:

I don't know what to think anymore. I guess we are not using PHP.