I was told by a client that they were having issues synchronizing software updates using SCCM 2012.
The first thing I checked was the Wsyncmgr.log to find out what was going on. The Wsyncmgr.log showed “Sync failed: The request failed with HTTP status 503: Service Unavailable. Source: Microsoft.UpdateServices.Administration.AdminProxy.CreateUpdateServer”
On the SCCM 2012 server running the SUP role, I opened up IIS Manager, looked at the Application Pools and noticed that the WsusPool was set to “Stopped“. I started it again and thought it was fixed, but the client advised me that it had crashed again shortly later.
I checked Task Manager on the server and noticed that IIS Worker Process was using 1864.1MB of memory.
I then right clicked on the WsusPool back in IIS Manager, then Advanced Settings, and noticed that the memory limit was set to a lower ammount.
I increased this limit to 4GB to be safe, restarted the WsusPool and then the SUP was able to syncrhonize fine. The Wsyncmgr.log looked good and the problem never came back for the client.