Apache is a great web-server, but it has a pretty heavy memory footprint. It can get quite restrictive quite quickly, especially if you’re on a system will limited resources (given how many people now run on a VPS, and the poor disk IO of these systems it’s all the more important – swapping is slow).
The way around it, is to configure your system to use NGinx as a reverse-proxy. Depending how many virtualhosts you have, you can make the changes almost completely transparently within about 10 minutes.
Pre-Requisites
First, we need to be able to install NGinx, which means setting up the EPEL repo (if you already have it enabled, skip this step)
CentOS 6.x
rpm -Uvh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
Now that the repo is installed, we need to install NGinx
yum install nginx
Configuring NGinx
Now that NGinx is installed we need to create a VirtualHost (actually NGinx calls them Server Blocks) for each site we are hosting.
nano /etc/nginx/conf.d/virtual.conf
#Insert one of these for each of the virtualhosts you have configured in Apache
server {
listen 80;
root /path/to/site/root;
index index.php index.html index.htm;
server_name www.yourdomain.com yourdomain.com;
location / {
try_files $uri $uri/ /index.php;
}
location ~ \.php$ {
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $remote_addr;
proxy_set_header Host $host;
proxy_pass http://127.0.0.1:8080;
}
location ~ /\.ht {
deny all;
}
}
This configuration tells NGinx to try and serve the requested file, but to pass the request onto Apache if it’s unable to do so. Requests for PHP files should be forwarded automatically. Apache will be told who requested the file in the ‘X-Forwarded-For’ header.
