Varnish is a reverse proxy cache that can make eZ Publish sites faster by caching pages, assets, and database queries. It handles caching on the reverse proxy level by checking requests for cache hits and fetching content from the web server only on misses. Configuring Varnish involves writing VCL configuration files to define caching rules and purge mechanisms. Integrating it with eZ Publish also requires customizations and extensions to leverage caching and purging features. Proper configuration of caching rules, TTLs, and purge handling is needed to optimize performance.

1. Varnish
Making eZ Publish sites fly
Peter Keung
http://www.mugo.ca

2. eZ DFS
Web Web Web
NFS MySQL
http://www.mugo.ca

3. Predictably unpredictable
http://www.mugo.ca

4. Varnish: What
Reverse proxy
1. request 2. MISS
Visitor #1 Varnish Web app
4. response 3. response
Web app
1. request
Visitor #2 Varnish
zzzzzz
zzzzzzz
2. HIT zzzzz
http://www.mugo.ca

5. Varnish: What
https://www.varnish-cache.org/
Example: Varnish on port 80; Apache on port
88
Serve HTTP GET requests: HTML and assets
very very very very very fast
Can sit on each web server
Can be a load balancer
Saint and grace modes
http://www.mugo.ca

6. Varnish: Why
Traffic spikes!
vs more hardware
Cost
Reliance on NFS
vs CDN
Cost
Closer to the application, more hands on
Not closer to the user
Use together
http://www.mugo.ca

7. Optimize everywhere
Apache, MySQL, eZ Publish
Browser caching
Minifying CSS and JS
http://www.mugo.ca

8. Varnish + eZ Publish
eZ Market extension
http://ez.no/Products/eZ-Market
Mugo Varnish extension:
https://github.com/mugoweb/mugo_varnish
http://www.mugo.ca

9. How to integrate
Custom static cache handler
https://github.com/ezsystems/ezpublish/pull/119
eZ Publish 2011.9 or 4.7
ezpEvent since 4.5
Purge specific URLs in Administration Interface
http://www.mugo.ca

10. Configuring Varnish
VCL
Similar to C
vcl_recv: what to do with the request
vcl_hit / vcl_miss
vcl_fetch: what to do with the response
vcl_deliver: send the response back
TTL
http://www.mugo.ca

11. vcl_recv: purge
if( req.request == "PURGE" )
{
# Limit access for security reasons
if( !client.ip ~ purge )
{
error 405 "Not allowed.";
}
# URL purges -- one for the URL and one for all view parameter variations
if( req.http.X-Purge-Url )
{
set req.http.X-Purge-Url1 = "^" + req.http.X-Purge-Url + "$";
set req.http.X-Purge-Url2 = "^" + req.http.X-Purge-Url + "/(";
ban( "obj.http.x-url ~ " + req.http.X-Purge-Url1 );
ban( "obj.http.x-url ~ " + req.http.X-Purge-Url2 );
error 200 "URL Purged.";
}
# Any regular expressions here
if( req.http.X-Purge-Reg )
{
ban( "obj.http.x-url ~ " + req.http.X-Purge-Reg );
error 200 "Regular Expression Purged.";
}
error 405 "Missing X-Purge-Url or X-Purge-Reg header.";
}
http://www.mugo.ca

12. vcl_fetch: setting TTL
# Only cache www.yoursite.com
# Only 200 responses
if( req.http.host == "www.yoursite.com" &&
beresp.status == 200
)
{
if( req.url ~ "^/var/plain/storage/images/.*" )
{
set beresp.ttl = 30d;
set beresp.http.X-Ttl = "30d";
}
else
{
# Default caching time
set beresp.ttl = 300s;
set beresp.http.X-Ttl = "300s";
}
}
http://www.mugo.ca

13. vcl_deliver: adding diagnostic info
set resp.http.X-Served-By = server.hostname;
if (obj.hits > 0)
{
set resp.http.X-Cache = "HIT";
set resp.http.X-Cache-Hits = obj.hits;
}
else
{
set resp.http.X-Cache = "MISS";
}
http://www.mugo.ca

14. Tweaks
Cookies: eZ Publish < 4.4
Controlling TTL and excluding pages
header( 'Edge-control: cache-maxage=86400s' );
{ezpagedata_append( 'http_headers', 'Edge-
Control: cache-maxage=0s' )}
Edge Side Includes
http://www.mugo.ca

15. Ongoing maintenance
varnishstat
varnishadm
curl -I http://www.yoursite.com
HTTP/1.1 200 OK
Server: Apache
X-Cache-Hits: 17
X-Cache: HIT
X-Served-By: CloudWeb2
Via: 1.1 varnish
X-Ttl: 300s
X-Powered-By: eZ Publish
Age: 206
http://www.mugo.ca

16. Relax
Questions? hi@mugo.ca
http://www.mugo.ca