memcache-session-multi.md

APACHE

  Apache Using

update the repository and install Apache.

apt-get update
apt-get install apache2

Install PHP and Apache's mod_php extension.

apt-get install php5 libapache2-mod-php5 php5-mcrypt

Install Memcache Packages

apt-get install php5-memcache memcached

Config memcache

nano /etc/memcached.conf

#host 1
-l 1.1.1.1

#host 2
-l 2.2.2.2

#host 3
-l 3.3.3.3

service memcached restart

Set Memcache as PHP's Session Handler

session.save_handler = memcache
session.save_path = 'tcp://1.1.1.1:11211,tcp://2.2.2.2:11211,tcp://3.3.3.3:11211'

Configure Memcache for Session Redundancy

memcache.allow_failover=1
memcache.session_redundancy=4

restart Apache

service apache2 reload

Test Session Redundancy

<?php
    header('Content-Type: text/plain');
    session_start();
    if(!isset($_SESSION['visit']))
    {
        echo "This is the first time you're visiting this server\n";
        $_SESSION['visit'] = 0;
    }
    else
            echo "Your number of visits: ".$_SESSION['visit'] . "\n";

    $_SESSION['visit']++;

    echo "Server IP: ".$_SERVER['SERVER_ADDR'] . "\n";
    echo "Client IP: ".$_SERVER['REMOTE_ADDR'] . "\n";
    print_r($_COOKIE);
?>

NGINX

   Install Nginx with PHP-FPM and Memcached Support

[x] Step 1: Install Nginx

sudo apt update
sudo apt install nginx
sudo systemctl stop nginx.service
sudo systemctl start nginx.service
sudo systemctl enable nginx.service

[x] Step 2: Install Memcached

sudo apt install memcached
sudo systemctl stop memcached.service
sudo systemctl start memcached.service
sudo systemctl enable memcached.service

[x] Step 3: Install PHP-FPM with Related Nginx Memcached Modules

sudo apt-get install php-fpm php-memcached php-cli