I followed the tutorial about Health Checks and implemented the example of the check for the Robots.txt file. => https://our.umbraco.com/documentation/Extending/Health-Check/

I did get some unexpected behaviour however not described in the manual.

It seems that in the backed when you to the health check section, group SEO and perform all checks that it works.

What I didn't know is when you don't go to health check the health check still seems to run periodically, I noticed this because I had a breakpoint in this code and was running in the backend with Debug enabled.

This has some implications, for instance this line in the example is incorrect: var success = File.Exists(HttpContext.Current.Server.MapPath("~/robots.txt"));

Because HttpContext.Current is null when it's run automatically.

Also I was planning to create a health check on all pages to check for broken links, this will however require a lot of resources and should run attended because you want to see the list of pages with errors. It has to run attended in order to function properly. Also if you make an error in your health check wordt case scenario it can crash your website at a random time ?

So my questions is basicly how to control it?

And is there a way for me to fix this documentation, because it has to mention the automatic running of these custom health checkes.

And there has to be a check for HttpContext.Current != null in the code sample.