Quiz

Will do! I'm trying to get more information about what exactly the students perceived. I'm guessing it might be something to do with the time on the PC shifting while the student was doing the quiz (maybe automatically syncing the time with the domain controller or something), but it really is only a guess at the moment.

I'll let you know if I get any further with it.

I'm still not completely sure what's going on here, but I think it may be a problem with the time on our servers. We have a 4-node cluster of app servers which are all being synchronised to the university's NTP servers, but (for some reason or another) it's being done with ntpdate in a cron job rather than ntpd, and we've discovered that the clocks on a couple of the servers were drifting almost 5 seconds out between runs. This, coupled with the fact that our load balancer is no longer using sticky sessions, may have meant that the remaining time being reported on changing quiz pages was inaccurate.

I'm going to speak to our infrastructure guys to see if they can either get the server clocks synchronised within 1 second at all times, or reinstate sticky sessions on the load balancer so that a quiz attempt would all be served from a single node, and see if that helps.