More Related Content
Globo.com & Varnish
- 1. HTTP accelerator Cachos 2.0 Luis Henrique Okama Tollef Fog Heen Mario Carvalho
- 2. What is theproblem? GET / HTTP/1.1 Hang on, I need to look up a few hundred things in my database and then do a lot of editing controlled by a scripting language HEAD / HTTP/1.1 Hang on, I need to look up a few hundred things in my database and then do a lot of editing controlled by a scripting language, and then I will throw the result away.
- 3. Why are CMS-esslow? Complex content generation process Single database prevents clustering Expensive software ditto This means: we need server side caching
- 4. Why are theexisting solutions not good enough? Squid, ancient design, forward proxy Apache, not what it's built for, not what it's good at Akamai (and similar), expensive, vendor lock-in
- 5. What is Varnish? Dedicated HTTP accelerator Focus on server-side speedups Policy control High performance Varnish Configuration Language Shared memory log
- 6. High performance 11syscalls + 7 locks for a cache hit Work with the OS, not against it. Multi-CPU, multi-core 64 bit Use advanced OS features: Accept filters madvise(MADV_RANDOM) kqueue, epoll Don't copy data if you don't have to Use workspaces, not malloc/free Compiled configuration
- 7. Policy control Override TTLs Add, remove or change headers Strip cookies Rewrite URLs Invalidate objects in the cache
- 8. Varnish Configuration Language Simple domain specific language Compiled via C language to binary Transparently! Dynamically loaded Multiple configs loaded concurrently Instant switch from one VCL to another. Can be done from VCL
- 9. VCL Example acl some_acl { "10.0.0.0/8" } if (client.ip ~ some_acl) { pass; } if (req.http.host ~ "foo.com$") { set req.http.host = regsub(req.http.host, "foo.com", "bar.org"); } if (obj.valid) { set obj.ttl = 10m; deliver; }
- 10. Shared memory logfile Fast Custom log tailers varnishtop varnishlog varnishhist varnishncsa varnishstat
- 11.
- 12. Comparative scalability setup time cost open source throughput physical space
- 13. Comparative scalability setup time cost open source throughput physical space
- 14. Comparative scalability setup time cost open source throughput physical space
- 15. Comparative scalability setup time cost open source throughput physical space
- 16. Comparative scalability setup time cost open source throughput physical space
- 17. Comparative scalability setup time cost open source throughput physical space
- 18. Comparative scalability setup time cost open source throughput physical space
- 19.
- 20. Conclusion softwarecustomization work set
- 21.
- 22.
- 23. Contacts LuisH. Okama okama@corp.globo.com (www.globo.com) Mario Carvalho mariocar@corp.globo.com (www.globo.com) Tollef Fog Heen tfheen@redpill-linpro.com (www.varnish-cache.com) @ Stand Globo.com