15.6.11

Gold Sponsor ofDrupalCamp Kyiv 2011

15.6.11

Silver Sponsors ofDrupalCamp Kyiv 2011

What is Varnish and how it Works

Varnish caches backend responsesand delivers from the cache

Varnish stores cache entryfor each Host + URL

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

Pressflow Pros and Cons

Server Config

Tuning and administering Varnish

VCL - Varnish configuration language – allows to hook most of the events during handling requestsCommand line optionsVarnish Tools – cache viewer, stats viewer,

Varnish Configuration Language

C-like syntaxSupports regular expressionsGets translated to C code then compiled and executedHooks: vcl_recv, vcl_pipe, vcl_pass, vcl_hash, vcl_hit, vcl_miss, vcl_fetch, vcl_deliver, vcl_discard, vcl_errors

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; }}

Case StudiesNon-Drupal Websites

livejournal.com weather.com slideshare.netDrupal Websites drupal.org fusemusic.com

Read more

http://www.varnish-cache.orghttp://www.pressflow.orghttp://www.google.com