There have been no unexpected outages (save the time in my holidays, when I shut down the server, that's located in my home office by now consuming my privately paid electricity :-) ).
I will move the jobe server to our school now, when school starts again.
But there may be times, the jobe will be down or not reachable, e.g. the DSL-wire or the router/proxy in our school gets stuck or the mains is down for electricians working on the installations or the DDNS service has issues.
There may also be situations, when I shut down the server myself expecting no student to use my courses at the moment, but some do use them anyway - who knows (hope dies last).
I know, that if you select jobe as the sandbox, the red message "Unexpected error..." is displayed. But it appears after the student has tried to check in his solution. He could be disappointed or frustrated this way. Better if he knows the outage before and does not try.
(Also I'm not sure, if my students will really read or understand the english message...)
That's why I created the small script (messages are German)
If jobe responds:
If connection fails: