We have a problem where our Lync clients are repeatedly requesting some of the user photos (from their Favorites list) from our Exchange server. Exchange serves it up, and the cache file on the local client seems to be updated, but then a second or so later the client makes the same request. The result of 100s of Lync clients making these requests continually is that our mail server sits at 80-90% CPU utilization when it's usually around 30% without these requests. Very odd.
The Exchange logs look like this but rotating between about 15 user photos (out of about 300):
2015-03-23 16:12:40 X.X.X.X GET /EWS/Exchange.asmx/s/GetUserPhoto email=<user_sip_address>&size=HR648x648 444 <domain>\<requester_username> X.X.X.X OC/15.0.4701.1000+(Microsoft+Lync) - 200 0 0 31
...where X.X.X.X is the mail server IP and <user_sip_address> is the address of the user whose photo is being requested. (And domain and requester username seem self explanatory.) The URL is legit; I can browse to it successfully.
I've removed and re-added the photos and cleared the local Lync cache. There is a missing piece here because it doesn't seem to be every user photo being requested nor does it seem to be every user in a specific Favorites list. Also, I didn't
seeing anything in the Lync client trace logs that seemed to coincide with the photos getting updated.
Anyone have any thoughts on how best to find a solution? Or perhaps you've run across this? Thanks for taking the time to read through my post! :-)