<?php

ini_set('session.save_handler', 'redis');
ini_set('session.save_path', 'tcp://localhost:6379');

session_name('FOOBAR');
session_start();

if (!array_key_exists('visit', $_SESSION)) {
    $_SESSION['visit'] = 0;
}
$_SESSION['visit']++;

echo 'You have been here ' . $_SESSION['visit'] . ' times.';

/**
 * This produces an error:
 * Warning: session_start(): Failed to read session data: redis (path: tcp://localhost:6379) in session.php on line 7
 */