Squid

When you're debugging a tough problem you sometimes need to analyze the HTTP traffic flowing between your machine and a webserver or proxy. Sometimes you can use firebug or chrome inspector for that. But here's a lowlevel alternative that I'm pretty excited about. Meet Tshark.

If you're running Squid to cache your website, you can use an htaccess file to control what kind of files should be cached, and for how long.

Let's say your site is becoming a big success and as a result it's becoming slower and slower. There are several things you can do without buying additional hardware:

I recently had to install a couple of squid servers to act as reverse proxies for a webcluster. You can teach the squid server to stand in between in the end users and the webservers, and to store all the static content ( .jpg .flv .css .htm for example ) in the RAM. This saves a lot of I/O and bandwidth on the webservers, and it can really speed up a site. At the end of the road the webservers' load dropped by 92%. But before all this worked, I had to run through a massive config file and since the squid config file is their manual at the same time, it's about 5000 lines long. So I had to find out a way to filter only the important settings from the config file.