2. Gold Sponsor of
DrupalCamp Kyiv 2011
15.6.11

3. Silver Sponsors of
DrupalCamp Kyiv 2011
15.6.11

4. What is Varnish and how it Works

5. Varnish caches backend responses
and delivers from the cache

6. Varnish stores cache entry
for each Host + URL

7. Pressflow
Pressflow = Drupal 6 with many performance
tweaks
Pressflow allows:
-
Lazy sessions creation
-
No cookies for anonynous users
- Lots of Drupal 7 performance tweaks
implemented

8. Pressflow Pros and Cons

9. Server Config

10. Tuning and administering Varnish
VCL - Varnish configuration language – allows to hook most of the events
during handling requests
Command line options
Varnish Tools – cache viewer, stats viewer,

11. Varnish Configuration Language
C-like syntax
Supports regular expressions
Gets translated to C code then compiled and executed
Hooks: vcl_recv, vcl_pipe, vcl_pass, vcl_hash, vcl_hit, vcl_miss, vcl_fetch,
vcl_deliver, vcl_discard, vcl_errors

12. Code Example
backend image_server {
.host = 127.0.0.1
.port = 1080
}
sub vcl_recv {
#direct image requests to image server
if(req.url ~ “(jpg|gif|png)”){
set req.backend = image_server;
}
}

13. Case Studies
Non-Drupal Websites
livejournal.com
weather.com
slideshare.net
Drupal Websites
drupal.org
fusemusic.com

14. Read more
http://www.varnish-cache.org
http://www.pressflow.org
http://www.google.com