[ic] 4.9.9 slowdown in admin screens

[Alex Schmelkin]

We are running a fairly high traffic IC site on the 4.9.9 core.  After a
number of tweaks with some great help from members of this list, we
still have a few remaining concerns.

After things stabilize, we are going to author a document of how we got
the site stable to support a few thousand concurrent shoppers on
distributed servers.

Most importantly, a number of pages in the backend that used to "FLY" in
the admin section now stall almost the point of unusable.  With a
similar number of ITEMS, the items tab in 4.9.8 used to take 10 seconds
to load.  Now it takes over 2 minutes. (same with merchandising).
Creating users on the backend used to be instant, and now takes close to
5 minutes some time.

We have also noticed that some pages which appear to be done processing
actually hang, as if the http connection remains open after the page has
actually finished processing.  Did something related to page buffering
change in 4.9.9?

There are no clues in any of the error logs.  The db indexes have not
changed in our upgrade from 4.9.8 to 4.9.9.

Any ideas?  Thank you all again so much for the help.  This list has
proved invaluable in our most recent deployment.

Thanks,
Alex
http://www.alexinteractive.com