Dear All,
I have a problem with my instance of Indico.
After opening the “Roles” tab under “Call for Abstracts=>Reviewing” in the management area, appears a popup with this error
Something went wrong
Request failed with status code 502
Dismiss (show next error)
In the error log file of Indico/Nginx I can see:
2021/04/13 10:42:50 [error] 2506#0: *17104 connect() to unix:/opt/indico/web/uwsgi.sock failed (11: Resource temporarily unavailable) while connecting to upstream, client: aaa.bbb.ccc.ddd, server: xyz, request: "GET /user/api/favorites/ HTTP/2.0", upstream: "uwsgi://unix:/opt/indico/web/uwsgi.sock:", host: "xyz", referrer: "https://eyx/event/1/manage/abstracts/".
I already changed the maximum number of connections in Nginx but the problem is not solved!
Is there someone can help me? 
Many thanks to everyone.
Anything interesting in indico.log?
Anyway, this looks like there’s a connection problem between nginx and uwsgi… but then I’d expect everything to be broken, not just this particular page.
In indico.log I see different of these rows:
2021-04-13 11:36:39,125 INFO 614a4d2c7e49443c 1 indico.rh POST /event/1/manage/api/principals [IP=aaa.bbb.ccc.ddd] [PID=379]
2021-04-13 11:36:39,125 INFO d3022e2800fb41e8 1 indico.rh POST /event/1/manage/api/principals [IP=aaa.bbb.ccc.ddd] [PID=20883]
2021-04-13 11:36:39,131 INFO 3766a558662a43bf 1 indico.rh GET /user/api/favorites/ [IP=aaa.bbb.ccc.ddd] [PID=32589]
but I think are not a errors.
The error appears only in this page, the other pages (and the system) seem to work correctly.
Enable the uwsgi log by adding logto = /tmp/uwsgi.log (or any other path - just make sure the permissions are fine in that case) to the uwsgi.ini. You may then find some more useful information in that log file.
I have just enable the uwsgi log and I see:
{address space usage: 652636160 bytes/622MB} {rss usage: 214134784 bytes/204MB} [pid: 2332|app: 0|req: 29/125] aaa.bbb.ccc.ddd () {56 vars in 1046 bytes} [Tue Apr 13 11:53:28 2021] POST /event/1/manage/api/principals => generated 313 bytes in 225 msecs (HTTP/2.0 200) 3 headers in 118 bytes (1 switches on core 0)
Weird… no idea what’s causing this to be honest. And not having any error in the uwsgi log entry doesn’t make it easier to track down…