Problem
When creating an exam, you get a status code 504 error in the UMC and it’s not possible to create the exam successfully.
This error can occur if you are using a reverse proxy server such as Nginx or HAproxy to allow connections to the nodes from outside the domain.
Solution
You will need to increase the timeout settings on the reverse proxy. In my case nginx was used as the reverse proxy and the default setting is 60 seconds. Increasing the setting to 120 seconds or 180 seconds will solve this problem.
See also:
Investigation
The error will be passed through the UMC and will therefore be displayed as a 504 error as it occurs on the reverse proxy.
The Apache error.log will log this as a 502 and the log entry may look like this
192.168.xxx.xxx - - [11/Oct/2024:15:54:54 +0200] "POST /univention/command/schoolexam/exam/start HTTP/1.1" 502 646 "https://portal.test.de/univention/management/?header=try-hide&overview=false&menu=false" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv: