UV not using cached thumbnails in image server

[Michael Levy]

It seems that UV is not using cached thumbnails. We're using UV 2.0.2 and Cantaloupe.  We haven't found much discussion of this point, but we noticed the behavior that we then found NedHenry described below and plan to try stripping out the query string via an Apache rewrite rule as he describes. I bring this up here because maybe others are having similar experiences.

In our case we often have well over 2,000 images in a manifest when representing a reel of microfilm. We will soon be bringing over 10 million images of materials from the Ukrainian State Archives available online; over 1 million images are available now: https://collections.ushmm.org/search/?f[browse][]=ukrdoc&q=Ukrainian

It would be good to have the thumbnails come from the cache instead of having to be regenerated every time. Is there a reason the query string described below shouldn't be stripped out? Is this configurable? Is this handled differently in version 3? Any advice would be appeciated.

Here's what NedHenry wrote:

"I also noticed that when the Universal Viewer loaded thumbnails, Cantaloupe wasn't using these cached thumbnails (though it's cache was working fine when I was testing it). I found that for some reason, UV was including a query string with a timestamp (e.g. ?t=123904839) which confusingly prevented our image server from using its derivative cache appropriately (I don't understand why)..."

"...to strip off the query string before sending the request to the image server, so it always uses the derivative cache when appropriate.... I have confirmed that this change allows complex objects to load much faster.."

https://github.com/UCSCLibrary/dams_project_mgmt/issues/36#issuecomment-548530809