At Tribute Media we have many sites in various stages of development. Sometimes upon returning to them I have noticed that Update Status has not checked for updates for up to 4 weeks. I then notice that the "drupal_http_request_fails" flag is set.
It is my understanding that when the variable "drupal_http_request_fails" is set the only way to get Drupal to re-attempt to make a request if to manually reset the variable. Drupal doesn't even check anymore until I reset the flag.
This module allows the user to configure when to check if the flag is set, and reset the flag. The interval is configurable from 1 minute to days or weeks.
When the interval times out the module checks "drupal_http_request_fails" to see if it is set to TRUE - meaning that no HTTP requests are being attempted - this module will reset the flag and log to the watchdog table. If the variable is set to FALSE - meaning that there is no problems making HTTP requests - it logs this to the watchdog table as well.
There are many things that can cause the "drupal_http_request_fails" flag to be set to TRUE, one of these is having the site offline. Drupal tries to make a connection to itself to make sure it can make http requests, if the site is offline it gets the Maintenance page instead of the page it is expecting, so it thinks it cannot make http requests. If the site is not set to offline you should investigate why the "drupal_http_request_fails" flag keeps getting set, this module should never be used on a live site.