Issue Summary

We received support cases from users saying that Trello isn’t working for them after moving a card.
This happened twice for a particular user and was caused by them moving a single card across boards. In that case analysis, the first time they moved a card, it used 33 million MS of Mongo time; the second time, it took 38 million MS, as when moving a card across boards, we also have to move all the actions for that card across boards. Using this much Mongo time causes them to exceed their Mongo time rate limit capacity, which means other requests will receive a 429.

Steps to Reproduce

1. Move a card with many actions to another board.

Expected Results

Users should be able to keep working on Trello after moving a card.

Actual Results

Trello stops working for several minutes. Logs show 429 responses. 

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available.