One of our teams uses a workboard to triage tasks (both features and bugs). The workboard has several columns to track tasks that need to be accomplished for each stage of release - 50% of beta users, 100% of beta users, all users, and future tasks. All in all, there are 5 columns and 26 task cards. The workboard is sorted by priority, so that they can focus on the highest priority tasks for each stage of release.
The issue is that moving cards from one column to another takes an extremely long time, up to a full minute, during which time no other cards can be moved. This makes the board almost unusable for their triage meetings.
This seems to only affect cards that have been assigned a priority, and only when the board is sorted by priority.
Reproduction
I was able to reproduce this by just creating a board, adding some tasks and giving them priorities, and sorting by priority:
This operation - moving the card Test04 from the column Test2 to Test1 - took 59 seconds. A majority of operations took 15-30 seconds.
Version Information
phabricator 861ac60e1fb5fe95feff74b3ce13547f3bb73728 (Thu, Jan 5) arcanist d6e112aecf93c208e3c299b4a4db7908f70f6f1d (Nov 16 2016) phutil ab80dcf99c6bf01a8d0fcd93bf529b04e9e3dcb2 (Fri, Dec 23) pytest-phabricator 5be92a18cd4d0b72f70303cc862cbc69e49a3af8 (Thu, Jan 5)
More Details
Just to confirm that the delay is due to the time taken by the request to https://<our-phabricator-host>/project/move/<project-id>/:
Tried tailing /var/log/apache2/error.log, nothing there pertaining to this issue.