I am working on a online exam website build in Laravel 5.5 and Mysql as database where student can login and give online exams in a duration of time.
Suppose there is a exam that has duration of 60 minutes (3000 seconds)
Now what i did is to track exam countdown timer is that i am sending a request to server each second. I am doing this because if in any case network lost, power cuts or student turns off his/her computer intentionally then I'll have a track that student has consumed how much time (in seconds).
So next time when student start that exam on the same/different computer i can resume that exam with the remaining time.
This worked quite fine with less number of students.
But when there are 150 students giving exam together then server is getting 150 requests each second. So Server load is about 135 (2 CPUs). I checked it in WHM.
Let me inform you that my client is using VPS having 2 CPUs processor with 4GB RAM.
My client says that number of students can increase. But increase server configuration is not a feasible solution.
So my question is how can i track the countdown timer and store that time on my server so that if for any reason exam stops then next time it can be resumed from the point it was stopped. No matter student is using same computer or not.
Please guide me.