How to Optimize Varnish Cache server for WordPress Blog.

For optimizing Varnish cache server for WordPress you need to tell varnish  server, which pages of your site to cache and which one not to cache. You need to write rules to normalize URL’s, time to serve content from cache and much more. All is possible by using the Varnish VCL, Language, the more you optimize your varnish VCL more you can handle the traffic.
Some points when using Varnish to Cache WordPress Blog.

1. Don’t cache WP-admin, so you can Login to WordPress dashboard.
2. Forward user IP to Backend Apache server so WordPress can obtain an origin IP in the comments instead of Varnish cache server IP address.
3. Remove cookies from static pages so that Varnish can cache Pages Properly.
4. Auto purge (Remove cached content) Varnish cache when someone comment or you publish new Post.
5. Don’t cache WordPress Post preview, to keep that feature working.
6. Don’t cache sitemap Page of your site, else when you purge your cache search engine bots again read your site whole sitemap.(This i come to Know From Google Webmaster Tools, when i use to cache Makeyouadmin sitemap, Every time I purge Varnish cache Google Webmaster tools shows URLs submitted and URLs indexed 0 in Sitemap section. When the Google bots visit my site again, everything becomes normal.).
7. Don’t cache search results, so that user can see fresh content when they search something from your site.

Keeping above mentioned points in mind, I have created Varnish VCL which is best suited for a simple WordPress blog. It is fork of TheNextWeb site Varnish VCL file with some of the customization.

Optimize Varnish Cache Server for WordPress


Before you get started with this Part of tutorial you need to setup Varnish cache server on your server. Please Follow Install Varnish cache server on Ubuntu and then come back and use this tutorial to optimize Varnish for WordPress.
First of Backup, your current default VCL, use below command to make Backup of file.

cd /etc/varnish
cp varnish.vcl varnishbkp.vcl

After that delete current default.

rm default.vcl

Then create new vcl with your favorite text editor.

nano default.vcl

After that copy paste below content into it.

backend default {
.host = "127.0.0.1";
.port = "8000";
.connect_timeout = 600s;
.first_byte_timeout = 600s;
.between_bytes_timeout = 600s;
}
acl purge {
"localhost";
"127.0.0.1";
"Server Public IP";
}
sub vcl_recv {
# set standard proxied ip header for getting original remote address
set req.http.X-Forwarded-For = client.ip;
set req.grace = 30m;
if (req.request == "PURGE") {
if (!client.ip ~ purge) {
error 405 "Not allowed.";
}
ban("req.url ~ "+req.url);
error 200 "Purged";
}
### NORMALIZE
# Cleanup URLs like /iframe=true&width=90%&height=90%
if(req.url ~ "iframe=true(.*)$") {
set req.url = regsub(req.url,"iframe=true(.*)$","");
error 301;
}
# Normalize the url - first remove any hashtags (shouldn't make it to the server anyway, but just in case)
if (req.url ~ "\#") {
set req.url=regsub(req.url,"\#.*$","");
}
# Strip out Google Analytics campaign variables. They are only needed
# by the javascript running on the page
# utm_source, utm_medium, utm_campaign, gclid
if(req.url ~ "(\?|&)(gclid|utm_[a-z]+)=") {
set req.url = regsuball(req.url, "(gclid|utm_[a-z]+)=[-_A-z0-9]+&?", "");
set req.url = regsub(req.url, "(\?|&)$", "");
}
# remove awesm referrers from query string
if(req.url ~ "(\?|&)awesm=") {
set req.url = regsub(req.url, "\?.*$", "");
}
# remove startIndex from query string
# not sure what this does
if(req.url ~ "(\?|&)startIndex=") {
set req.url = regsub(req.url, "\?.*$", "");
}
# remove fb_xd_fragment from query string
if(req.url ~ "\?fb_xd_fragment") {
set req.url = regsub(req.url, "\?.*$", "");
}
# remove comment-page-1 from query string
# this is the same page as the post page
if(req.url ~ "comment-page-1") {
set req.url = regsub(req.url, "comment-page-1", "");
}
# remove double // in urls,
set req.url = regsuball( req.url, "//", "/" );
// remove extra http:// calls at the end of the url
if (req.url ~ "^/\?http://") {
set req.url = regsub(req.url, "\?http://.*", "");
}
### END NORMALIZE
# Normalize Content-Encoding
if (req.http.Accept-Encoding)
{
if (req.url ~ "\.(jpg|png|gif|gz|tgz|bz2|lzma|tbz)(\?.*|)$") {
remove req.http.Accept-Encoding;
} else if (req.url ~ "\.(js|css|txt|html|htm)(\?.*|)$") {
# text files - do compression
if (req.http.Accept-Encoding ~ "gzip") {
set req.http.Accept-Encoding = "gzip";
} elsif (req.http.Accept-Encoding ~ "deflate") {
set req.http.Accept-Encoding = "deflate";
} else {
remove req.http.Accept-Encoding;
}
}
}
# never cache twitter oauth login unless it are images
if (req.url ~ "^/[^?]+\.(jpeg|jpg|png|gif|ico|js|css|txt|gz|zip|lzma|bz2|tgz|tbz|html|htm)(\?.*|)$") {
# Remove cookies and query string for real static files
unset req.http.cookie;
}
else if(req.url ~ "/sitemap.xml"){
return (pass);
}
# File type that we will always cache
if (req.request == "GET" && req.url ~ "\.(gif|jpg|swf|css|js|png|jpg|jpeg|gif|png|tiff|tif|svg|swf|ico|css|js|vsd|doc|ppt|pps|xls|pdf|mp3|mp4|m4a|ogg|mov|avi|wmv|sxw|zip|gz|bz2|tgz|tar|rar|odc|odb|odf|odg|odi|odp|ods|odt|sxc|sxd|sxi|sxw|dmg|torrent|deb|msi|iso|rpm)$") {
return(lookup);
}
# logged in users must always pass
# Removed req.http.Cookie ~ "wordpress_logged_in_"
if(req.url ~ "\?esi$") {
} else if( req.url ~ "^/[^?]+/wp-(login|admin)" || req.url ~ "^/wp-(login|admin)" || req.url ~ "preview=true") {
return (pass);
}
# Resize images
if( req.url ~ "\.png\?s=60" ){
}
elsif( req.url ~ "\?s="){
# don't cache search results
return (pass);
}
# always pass through posted requests and those with basic auth
if ( req.request == "POST" || req.http.Authorization ) {
return (pass);
}
# else ok to fetch a cached page
unset req.http.Cookie;
return (lookup);
}
sub vcl_fetch {
# Serve items up to half an hour past their expire time
set beresp.grace = 30m;
set beresp.ttl = 48h;
# cache ESI requests for 5 minutes
if (req.url ~ "\?esi$") {
set beresp.ttl = 5m;
}
if (beresp.http.esi-enabled == "1") {
set beresp.do_esi = true;
#unset beresp.http.esi-enabled;
}
# You are respecting the Cache-Control=private header from the backend
if (beresp.http.Cache-Control ~ "private") {
set beresp.http.X-Cacheable = "NO:Cache-Control=private";
# You are extending the lifetime of the object artificially
} elsif (beresp.ttl < 1s) { set beresp.ttl = 5s; set beresp.grace = 5s; set beresp.http.X-Cacheable = "YES:FORCED"; # Varnish determined the object was cacheable } else { set beresp.http.X-Cacheable = "YES"; } # don't cache response to posted requests or those with basic auth if ( req.request == "POST" || req.http.Authorization ) { return (hit_for_pass); } # cache 404s and 301s for 1 minute if (beresp.status == 404 || beresp.status == 500 || beresp.status == 301 || beresp.status == 302) { set beresp.ttl = 1m; return (deliver); } # any other request except 200 if ( beresp.status != 200) { return (hit_for_pass); } # else ok to cache the response #set beresp.http.X-expires = beresp.ttl; return (deliver); } sub vcl_deliver { # add debugging headers, so we can see what's cached if (obj.hits > 0) {
set resp.http.X-Cache = "HIT";
}
else {
set resp.http.X-Cache = "MISS";
}
}
sub vcl_hash {
# convert request in hash for cache lookup
hash_data(req.url);
}
sub vcl_error {
# retry connecting to apache 3 times before giving up
if (obj.status == 503 && req.restarts < 2) {
set obj.http.X-Restarts = req.restarts;
return(restart);
}
if (obj.status == 301) {
set obj.http.Location = req.url;
set obj.status = 301;
return(deliver);
}
}
sub vcl_hit {
if (req.request == "PURGE") {
error 200 "OK";
}
}
sub vcl_miss {
if (req.request == "PURGE") {
error 404 "Not cached";
}
}

Before saving changes, make sure change Highlighted Red IP address and Port number with your server port.After that press ctrl+x and press enter to save changes.

service varnish restart

Now you can Browse your website in your browser, in my next post i will share some tools and tips which help you know whether the Varnish cache server is working properly and healthy.

URL: http://gtmetrix.com or http://www.webpagetest.org