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| — | varnish [2012/02/15 04:00] (current) – created - external edit 127.0.0.1 | ||
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| + | ====== varnish ====== | ||
| + | |||
| + | Varnish is a web accelerator. | ||
| + | |||
| + | Wikipedia: A web accelerator is a proxy server that reduces web site access times. They can be a self-contained hardware appliance or installable software. | ||
| + | |||
| + | ==== Configuration ==== | ||
| + | |||
| + | Edit ''/ | ||
| + | < | ||
| + | backend default { | ||
| + | .host = " | ||
| + | .port = " | ||
| + | } | ||
| + | </ | ||
| + | |||
| + | The web server must accept connections on that IP address and serve the content. | ||
| + | |||
| + | Start varnishd: | ||
| + | < | ||
| + | varnishd -f / | ||
| + | </ | ||
| + | |||
| + | ==== Notes ==== | ||
| + | |||
| + | * Varnish can have several backends defined and can you can even join several backends together into clusters of backends for load balancing purposes. | ||
| + | * Be aware that every object that is stored also carries overhead that is kept outside the actually storage area. So, even if you specify -s malloc,16G varnish might actually use double that. Varnish has a overhead of about 1k per object. So, if you have lots of small objects in your cache the overhead might be significant. | ||
| + | * You can use Varnish to cache content from different servers, effectively splitting URLs across many backends. | ||
| + | * Varnish has a "saint mode" where it will only send a cache if there is a bad request returnedV from the original webserver. | ||
| + | * Varnish can act as a high availability server, balancing load between two backends. | ||
| + | |||
| + | ==== Ubuntu ==== | ||
| + | |||
| + | < | ||
| + | curl http:// | ||
| + | echo "deb http:// | ||
| + | apt-get update | ||
| + | apt-get install varnish | ||
| + | </ | ||
