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Evolved Caching is a highly performance orientated, advanced full page caching solution for Magento developed by Hussey Coding. It offers performance and functionality that we truly believe make it the premier choice for full page caching in the market place.As well as being an extremely effective caching solution in it's own right, Evolved Caching also integrates directly with Varnish by way of it's caching key cookie. This cookie is generated for every page as you navigate through your site and it contains a unique hash which describes many things about the way that page is displayed, such as the current store, the currency, any category or layered navigation filtering applied, whether the page is secure or insecure, the browser user agent, the tax rate according to the customers address, and of course the URL.
Varnish is designed to cache by URL, but this results in an incomplete solution in the case of Magento as quite a few aspects which govern the way a page is displayed are stored in a users session and won't necessarily appear in the URL at all (category page filtering is one example of this). This means that Varnish can end up serving the wrong content to the user as it doesn't account for, amongst other things, session data.
The caching key cookie however is built using logic which considers all of the different ways in which this kind of data can effect a page, it's the same logic in fact Evolved Caching uses to store it's own cached content. So with Varnish using the unique hash contained in the cookie, you have an effective, complete Varnish caching solution driven by the complex logic Evolved Caching already has built in.
As well as the caching key cookie meaning that you don't need to take on the significant task of providing Varnish with enough data to cache properly, it also tells Varnish which pages it should and shouldn't cache according to the excluded pages you configure in admin.
The end result of all this is that your Varnish configuration file only needs to be relatively few lines as all Varnish needs to do is cache and serve content according to the content of the cookie.
Although this post includes the sample .vcl files below, we won't cover the initial installation and setup of Varnish here. Installation is straightforward and covered for a number of different Linux distributions in the Varnish documentation. Initial setup is again simple and for many configurations, nothing more than is outlined under the installation exercise here will be required.
With Varnish installed and setup, you then need to edit your Varnish configuration file, which unless you have changed it during setup, can be found here on your server.
/etc/varnish/default.vclAgain the Varnish documentation has plenty of information about building a VCL in case you want to modify the configuration below, but we expect for you to be able to use the sample .vcl as it is.
So all you need to do is open default.vcl at the location above (or the one you specified if you changed it), delete it's contents and copy and paste into it the first sample .vcl below for Varnish 3, or the second sample below for Varnish 4.
Varnish 3
backend default {
.host = "127.0.0.1";
.port = "8080";
}
sub vcl_recv {
if (req.request == "BAN_HTML") {
ban("obj.http.Evolved-Type == html");
error 200 "ban_html";
return (error);
} else if (req.request == "BAN_IMAGES") {
ban("obj.http.Evolved-Type == image");
error 200 "ban_images";
return (error);
} else if (req.request == "BAN_CSSJS") {
ban("obj.http.Evolved-Type == cssjs");
error 200 "ban_cssjs";
return (error);
} else if (req.request == "PURGE_SINGLE") {
return (lookup);
} else {
if (req.url ~ "/form_key/" && req.http.Cookie ~ "evolved_formkey") {
set req.url = regsub(req.url, "/form_key/[^/]*/", "/form_key/" + regsub(req.http.Cookie, ".*evolved_formkey=([^;]+).*", "\1") + "/");
}
if (req.restarts == 0) {
if (req.http.x-forwarded-for) {
set req.http.X-Forwarded-For =
req.http.X-Forwarded-For + ", " + client.ip;
} else {
set req.http.X-Forwarded-For = client.ip;
}
}
if (req.http.Cookie !~ "evolved_key") {
return (pass);
}
if (req.request != "GET" &&
req.request != "HEAD" &&
req.request != "PUT" &&
req.request != "POST" &&
req.request != "TRACE" &&
req.request != "OPTIONS" &&
req.request != "DELETE") {
return (pipe);
}
if (req.request != "GET" && req.request != "HEAD") {
return (pass);
}
if (req.http.Authorization) {
return (pass);
}
return (lookup);
}
}
sub vcl_hash {
if (req.url ~ "\.(png|gif|jpg|jpeg|swf|css|js)$" && req.http.Cookie ~ "evolved_key") {
hash_data(req.url);
} else if (req.http.Cookie ~ "evolved_key") {
hash_data(regsub(req.http.Cookie, ".*evolved_key=([^;]+).*", "\1"));
}
return (hash);
}
sub vcl_hit {
if (req.request == "PURGE_SINGLE") {
purge;
error 200 "purge_single";
return (error);
}
}
sub vcl_fetch {
if (req.http.Cookie ~ "evolved_key") {
unset beresp.http.Set-Cookie;
if (req.url ~ "\.(css|js)$") {
set beresp.http.Evolved-Type = "cssjs";
if (beresp.ttl <= 0s) {
set beresp.ttl = 120s;
}
} else if (req.url ~ "\.(png|gif|jpg|jpeg|swf)$") {
set beresp.http.Evolved-Type = "image";
if (beresp.ttl <= 0s) {
set beresp.ttl = 120s;
}
} else {
set beresp.http.Evolved-Type = "html";
if (beresp.ttl <= 0s) {
set beresp.ttl = 120s;
}
}
}
return (deliver);
}
sub vcl_deliver {
unset resp.http.Evolved-Type;
}
Varnish 4
vcl 4.0;
backend default {
.host = "127.0.0.1";
.port = "8080";
}
sub vcl_recv {
if (req.method == "BAN_HTML") {
ban("obj.http.Evolved-Type == html");
return (synth(200, "ban_html"));
} else if (req.method == "BAN_IMAGES") {
ban("obj.http.Evolved-Type == image");
return (synth(200, "ban_images"));
} else if (req.method == "BAN_CSSJS") {
ban("obj.http.Evolved-Type == cssjs");
return (synth(200, "ban_cssjs"));
} else if (req.method == "PURGE_SINGLE") {
return (purge);
} else {
if (req.url ~ "/form_key/" && req.http.Cookie ~ "evolved_formkey") {
set req.url = regsub(req.url, "/form_key/[^/]*/", "/form_key/" + regsub(req.http.Cookie, ".*evolved_formkey=([^;]+).*", "\1") + "/");
}
if (req.http.Cookie !~ "evolved_key") {
return (pass);
}
}
return (hash);
}
sub vcl_purge {
return (synth(200, "purge_single"));
}
sub vcl_hash {
if (req.url ~ "\.(png|gif|jpg|jpeg|swf|css|js)$" && req.http.Cookie ~ "evolved_key") {
hash_data(req.url);
} else if (req.http.Cookie ~ "evolved_key") {
hash_data(regsub(req.http.Cookie, ".*evolved_key=([^;]+).*", "\1"));
}
return (lookup);
}
sub vcl_backend_response {
if (bereq.http.Cookie ~ "evolved_key") {
unset beresp.http.Set-Cookie;
if (bereq.url ~ "\.(css|js)$") {
set beresp.http.Evolved-Type = "cssjs";
if (beresp.ttl <= 0s) {
set beresp.ttl = 120s;
}
} else if (bereq.url ~ "\.(png|gif|jpg|jpeg|swf)$") {
set beresp.http.Evolved-Type = "image";
if (beresp.ttl <= 0s) {
set beresp.ttl = 120s;
}
} else {
set beresp.http.Evolved-Type = "html";
if (beresp.ttl <= 0s) {
set beresp.ttl = 120s;
}
}
}
return (deliver);
}
sub vcl_deliver {
unset resp.http.Evolved-Type;
}
Once you have done that, check that the backend default section at the top is correct and points at the reconfigured web server (as set during the initial Varnish setup), and also edit the three instances of 120s in the vcl_fetch/vcl_backend_response section at the bottom to however long you want HTML, CSS/JS and images to remain in the Varnish cache. This is set at the default of 120 seconds in the above sample .vcl, but you will very likely want to increase it. How much you increase it by really depends on your caching strategy and the size of cache you want to make available to Varnish, but the longer you hold items in cache, the larger your cache is going to be. A side note is that you can use values other than seconds so the following would for instance tell Varnish to hold items in cache for a week.
set beresp.ttl = 1w;A couple of notes to add, the first being that the above samples are Varnish 3 and Varnish 4 configuration files rather than 2.1, a number of key things change after version 2.1 which means that these sample .vcl files will not work with version 2.1.
The second note is to say that the above sample .vcl has been updated to work with changes introduced in Magento 1.8 CE to use form keys on the frontend. Combined with version 1.6.6 of Evolved Caching, it resolves this issue in your Varnish cache.
Finally, if you want to make use of the Varnish cache deleting and warming rules inside this .vcl, you must use version 1.6.9 or greater of Evolved Caching.
The only other thing to point out is that we recommend you use Evolved Caching 1.5.2 or later when it's going to be in conjunction with Varnish. If you have already purchased a license and have an earlier version than this we we will be happy to send you a more recent version free of charge, just drop us an email at sales@husseycoding.co.uk. Also note that since version 1.6.0 of Evolved Caching you have the option of using non AJAX based dynamic content updating. When using Varnish together with Evolved Caching you can only use AJAX based dynamic content updating, if you disable this your dynamic content will not be correctly displayed.
We highly recommend you thoroughly test this setup in a staging/development environment first, only then installing to your main production environment.
Finally if you would like assistance with configuring Varnish to work with your copy of Evolved Caching, then please contact us at support@husseycoding.co.uk and we will be happy to help.
If you want more information on Evolved Caching, then have a look at the full guide here. You can also find a summary of functionality, chat to us about it, and purchase it from our store here.
