I have been stumped on this for a few days now and have been running multiple tests, and the Time To First Byte is always “F” and as this test result shows it is just over a second. The site is running on sitefinity, and seems sometimes can be really fast as the test results show (2.9 seconds to me seems quite fast! Although there is always room for improvement) it can take up to 20 seconds to load the home page (this seems to be when a connection has been opened for a little while).
I have moved the site form its own server to the database server (to check for any connectivity issues but this seems to be hte same sort of speed (although I cannot check as the database server is not public facing).
Anyway any improvements suggestions would be greatly appreciated.
First byte problems are hard to solve from the outside because we generally don’t have the visibility to see what is causing the issues.
It can be anything from:
Database performance issues (check your slow query log if you are using a database)
External web service calls made by the server
Overloaded server
Server that has run out of available processes to handle requests
and a bunch of other things
If you don’t have an obvious smoking gun to look at and you have root/sudo access to the server I’m a huge fan of New Relic ( http://newrelic.com ) which gives you a breakdown of where your server time is going and it is usually just a matter of minutes to figure out what is going on (they have a 14 day free trial which is plenty of time to debug/fix/test). Otherwise you can also do manual logging/instrumentation.
I dont know if its me having one of those days but unfortunatly I cannot get the New Relic tool installed correctly (dont worry i am not asking for support!)
I am wondering if you have any other words of wisdom I also apologise as i forgot to post a link to the test result so here it is!
I haven’t done a lot of .net profiling but it looks like there are quite a few options. Here are a couple that came up when I searched:
Otherwise, there is always the tried and true method of sprinkling log messages through the code (you can output the timings to the page HTML as hidden comments or log to somewhere on disk).