We recently upgraded to WebWork 2.17 and MariaDB on a fresh Ubuntu 22.04 server. Everything seems to be functioning _except_ that when students (not instructors) submit answers, it takes WebWork a _very_ long time to respond.
The timing.log has items like the following:
- [Tue Aug 16 13:00:45 2022] 2442 1660672845 - [/webwork2/IL_114/Section_3.8/1/] [runTime = 0.068 sec sql_single]
which is when the student loaded the problem, but then later we see:
- [Tue Aug 16 13:06:50 2022] 2780 1660673210 - [/webwork2/IL_114/Section_3.8/1/] [runTime = 392.103 sec sql_single]
- [Tue Aug 16 13:07:13 2022] 2427 1660673233 - [/webwork2/IL_114/Section_3.8/1/] [runTime = 393.027 sec sql_single]
This seems to indicate that the student pressed "grade" twice, and it took a very, very long time to process. According to the students, they simply see the browser's spinning cursor of a webpage loading while this is going on--no feedback returned after clicking "grade". However, when they leave the problem and then navigate back to it, they see that the number of attempts has increased, and if they got it right, they see that it is now marked correct.
Over in the apache2.log, the POSTs corresponding to the two long runtimes are out of order from the time stamps:
- [16/Aug/2022:13:00:44 -0500] "GET /webwork2/IL_114/Section_3.8/1/?effectiveUser=...
- [several more unrelated lines]
- [16/Aug/2022:13:06:44 -0500] [**unrelated GET**]
- [16/Aug/2022:13:00:18 -0500] "POST /webwork2/IL_114/Section_3.8/1/ HTTP/1.1" 200 7027 "https://webwork.uwec.edu/webwork2/IL_114/Section_3.8/1/?effectiveUser=...
- [16/Aug/2022:13:07:06 -0500] [**unrelated**]
So I do not understand this delay, or where the hold up is occurring. Is it in an issue with apache? Is it in the database? Is it WebWork in the rendering of the content since the timing.log says that this took ~392 seconds?
This seems to be happening for every single student submission. But not for any instructors submissions, or any other WebWork navigation.
Of course we did not have this issue with WW 2.16 with the mysql db backend. Perhaps I have something misconfigured?
Any insights would be very much appreciated as we have live courses at the moment, and need to have this resolved ASAP. Thank you!