Q:

What would cause civicrm_invoke to submit a large number of server requests?

Earlier today, the civicrm_invoke process submitted a large number of requests to our server – so many requests that it took our site down. An agent at our host (Pantheon) had to restart our application instance to get our site back on-line.
My goal is to prevent this from happening again. To do that, I need to better understand why this happened, so I'm turning to y'all for some guidance:

What is civicrm_invoke?
What causes it to instantiate?
If there are obvious possible causes for a (seemingly) spontaneous "burst" of civicrm_invoke requests, what are they?

We're on a virtual server on Pantheon, running CiviCRM 4.7.8, Drupal 7.44, PHP 5.5.24. Our database is: 5.5.5-10.0.23-MariaDB-log. No extensions are installed. Cron has not run since April 18th (Yes, that's a problem. No, I don't know how I managed to get it to run in April. If anyone can point me at a way to manually force Civi's Cron to run, that'd be keen.).
Thanks!

A:

It isn't a process it's a function in the drupal module. It mostly gets called when a web request comes in. Check your apache logs for a large number of requests, maybe your site was hit by a botnet. At least the logs would tell you IPs.

