W3 Total Cache + (optional) Domain Mapping

Update: This article is updated for WordPress 3.5 multisite’s file-handling and new W3-Total-Cache page-cache directory structure.

In this article, we will setup WordPress Multisite using subdomains with Nginx with added support for W3 Total Cache Plugin.

If you haven’t created a WordPress Multisite network, please check this guide first.

Nginx Config

Below is recommended Nginx configuration.

server {
        ##DM - uncomment following line for domain mapping	
        #listen 80 default_server;
	server_name example.com *.example.com ;
	##DM - uncomment following line for domain mapping
	#server_name_in_redirect off;

	access_log   /var/log/nginx/example.com.access.log;
	error_log    /var/log/nginx/example.com.error.log;

	root /var/www/example.com/htdocs;
	index index.php;

	set $cache_uri $request_uri;

	# POST requests and urls with a query string should always go to PHP
	if ($request_method = POST) {
		set $cache_uri 'NULL';
	}
	if ($query_string != "") {
		set $cache_uri 'NULL';
	}

	# Don't cache uris containing the following segments
	if ($request_uri ~* "(/wp-admin/|/xmlrpc.php|/wp-(app|cron|login|register|mail).php|wp-.*.php|/feed/|index.php|wp-comments-popup.php|wp-links-opml.php|wp-locations.php|sitemap(_index)?.xml|[a-z0-9_-]+-sitemap([0-9]+)?.xml)") {
		set $cache_uri 'NULL';
	}

	# Don't use the cache for logged in users or recent commenters
	if ($http_cookie ~* "comment_author|wordpress_[a-f0-9]+|wp-postpass|wordpress_logged_in") {
		set $cache_uri 'NULL';
	}

	# Use cached or actual file if they exists, otherwise pass request to WordPress
	location / {
		try_files /wp-content/cache/page_enhanced${cache_uri}_index.html $uri $uri/ /index.php?$args;
	}

	location ~ \.php$ {
		try_files $uri /index.php;
		include fastcgi_params;
		fastcgi_pass unix:/var/run/php5-fpm.sock;
	}

	location ~* ^.+\.(ogg|ogv|svg|svgz|eot|otf|woff|mp4|ttf|rss|atom|jpg|jpeg|gif|png|ico|zip|tgz|gz|rar|bz2|doc|xls|exe|ppt|tar|mid|midi|wav|bmp|rtf)$ {
		access_log off;	log_not_found off; expires max;
	}

	location = /robots.txt { access_log off; log_not_found off; }
	location ~ /\. { deny  all; access_log off; log_not_found off; }
	location ^~ /wp-content/w3tc- { deny  all; access_log off; log_not_found off; }
}

Above configuration is already tested for minification & browser caching. You can disable minification in  W3-Total-Cache settings.

Domain Mapping

You need to uncomment few lines in above nginx-config to get domain-mapping working. Apart from above config changes, you can read this guide to setup/configure domain-mapping.

Must Read:

• Checklist For Perfect WordPress-Nginx Setup - It will help you verify if your caching will work after PHP/MySQL crash.
• Nginx Maps for Better Static File Handling in WordPress-Multisite - useful for multisite created before WordPress 3.5 released
• WordPress-Nginx tutorials