Recently I wanted to make myself a short url host. Really, I made this not to make short urls, but to make memorable urls for myself.
tl;dr click here
When we talk about capturing metrics in applications. One server/service that constantly is in all conversations monitoring, is statsd. Incase you have never heard of it, statsd is a udp/tcp server that you send your in-code metrics to. These metrics get aggregated by statsd, and are forwarded to various backends. Some backends are services like librato or sumologic. Other times you are sending metrics to time series databases such as graphite or god forbid influxdb.
This boils down to in code you can say "log whenever this block of code is hit" or say "measure how long this function takes to execute". These stories come together to form pretty graphs, and rich alerts. All of this enabled by statsd.
For a while now I have been playing with rails, and rack webapps. If you are not familiar with these, they are webservers created in ruby. One of the features I ran into during my journey into ruby land is Turbolinks. Incase you are not familiar, Turbolinks is basically a simplified pjax, with a lot of flexibility. When you click on a link in a page with turbolinks, the link action is hijacked and the target page is loaded via ajax. The result of the ajax call (which is presumed to be html) will replace the document of the body tag. At the end of the day its a technology to load your server side pages via ajax.