Comment 1 for bug 1573288

This is present since Juno at least.

The issue seems to be that in Admin -> overview we ask nova for _all_ instances, even deleted ones, thus on a big deployment with instances coming and going everyday, this gets as slow as possible.

Mixed with the range that takes since the start of the month to display items, this gets worse the later in the month (as is displaying more and more days)

There is a patch (https://review.openstack.org/#/c/238204/) to make the overview ranges configurable so this would alleviate the issue, but it does not fix the real problem. Asking for all instances is very costly.

This should be discussed in a meeting to see what direction to take with the overview page.