One important thing to keep in mind about entering HTTP status codes in Cloudsome is that if you simply don’t enter anything (leave the field empty), Cloudsome will accept any HTTP code as a successful one. This is something we recommend by default.
If, however, you do need Cloudsome to watch for specific HTTP response codes, click into the field and it will drop down some options for you. Let’s say you only want to consider a host up if, and only if, it returns the 200 Ok code. No problem, pick it from the drop down and save the monitor.
Just remember that it’s very common for web hosts to return codes like 301 Moved Permanently or 302 Found and still be perfectly up and running.
Please, be sure to know precisely what HTTP code your hosts returns before you use this feature.
Here are several great resources to learn about HTTP status codes.