Varnish for Beginners

An introduction to Varnish the caching http accelerator. Showing some stats and a live demo of Varnish this presentation aims to bring unfamiliar users into the fold and to start using Varnish.

Transcript

1. Varnish for Beginners Shielding Drupal from the internet http://adammalone.net | http://drupal.org/user/1295980 | @adammalone By Adam Malone
2. What is Varnish http://adammalone.net | http://drupal.org/user/1295980 | @adammalone • Reverse proxy HTTP accelerator • Apache/Nginx • Memory based
3. Varnish Installation (yum|apt-get|brew) install varnish CentOS installation requires varnish repo http://adammalone.net | http://drupal.org/user/1295980 | @adammalone
4. Varnish Configuration http://adammalone.net | http://drupal.org/user/1295980 | @adammalone DAEMON_OPTS="-a :80 \ -u varnish -g varnish \ -T localhost:6082 \ -f /etc/varnish/adam.vcl \ -S /etc/varnish/secret \ -s malloc,256M" backend default { .host = "127.0.0.1"; .port = "8234"; } sub vcl... /etc/varnish/default.vcl /etc/sysconfig/varnish
5. VCL sub vcl_recv vcl_pipe vcl_fetch vcl_deliver vcl_error http://adammalone.net | http://drupal.org/user/1295980 | @adammalone return() pipe fetch restart deliver pass lookup error VCL docs Four Kitchens VCL request objs req besresp
6. Shielding Drupal from the Internet http://adammalone.net | http://drupal.org/user/1295980 | @adammalone
7. Checking Varnish works • Inspecting Headers • Watch the network tab • Check varnishlog (more later) • isvarnishworking.com http://adammalone.net | http://drupal.org/user/1295980 | @adammalone
8. Breaking Varnish • Setting $_SESSION ◦ Authenticated users do not benefit ◦ Check {sessions} table • Cookies • Unique query paths • .htaccess http://adammalone.net | http://drupal.org/user/1295980 | @adammalone
9. Varnish and Drupal http://adammalone.net | http://drupal.org/user/1295980 | @adammalone
10. Comparison to other caches • Drupal cache tables • Boost • MongoDB • Memcache http://adammalone.net | http://drupal.org/user/1295980 | @adammalone
11. Varnish Tools • varnishstat • varnishlog • varnishncsa • varnishhist http://adammalone.net | http://drupal.org/user/1295980 | @adammalone
12. Extending Varnish • ESI • Varnish mods (vmods) • Don't be too greedy when caching • Don't deliver too promiscuously http://adammalone.net | http://drupal.org/user/1295980 | @adammalone Gotchas
13. Questions adam@adammalone.net http://adammalone.net http://adammalone.net | http://drupal.org/user/1295980 | @adammalone