I'm currently working on design of small web service, and I have a following feature (simplified):
After some user actions, there is a wait period (ranging from 30sec to 40h) and after it's passed, the server should update database entry for the task, unless user cancelled it during the waiting period. Executed task is quite simple, just a few calculations, but it must be delayed.
And I have no idea how to do this...
I know that similar situation happens in some browser based games, where you upgrade a building and get bonuses from it after it's finished, but I was unable to find how this feature is achieved. So, my question is, is there a "state-of-art" method of dealing with such problems in backend, or any method at all?