2018-07-19: Updating an issue is very slow / times out

When an issue contains many (say, 100) ToDo items, updating it is really slow.

For instance, checking any of ToDo checkboxes takes dozens of seconds (see the PATCH request):

– 17.8 seconds for that PATCH request. This screenshot was taken few minutes ago on this page: NikolayS/my-awesome-project#1, 100 ToDo items.

For small lists, requests are still slow but much faster, see for example NikolayS/my-awesome-project#1 with 5 ToDos – the PATCH took 1.2 sec:

Sometimes, it reaches 60 sec timeout and fails with 502 error (w/o any noticeable UI changes), I've noticed it multiple times during July 16-18:

Editing & saving the issue's description is also slow (see PUT request):

Edited Jul 19, 2018 by Nikolay Samokhvalov