I had a customer that faced the following problem with WSUS, the customer has over 2500 computers and above 10,000 approved update. the problem was that the clients seemed to stopped getting updates, and all the clients enters an endless loop of checking for update.
by trying to access the WSUS console, it opens for seconds and then break giving the following message:
Error: Connection Error
An error occurred trying to connect the WSUS server. The error can happen for a number of reasons. Check connectivity with the server. Please contact your network administrator if the problem persists
Click Reset server node to try to connect to the server again.
The Solution that worked for me is by increasing the amount of memory the WSUS pool uses, which was 1.75 GB by default. Increasing this value to 15 GB approved that WSUS works with no problem and the clients start to report back and get updates.
Steps to increase the amount of RAM are as the following:
First open the IIS on the WSUS server and browse to Application Pools, Wsus Pool and select Advanced Settings.
On the new displayed windows select Private Memory Limit (KB) and enter your new Memory Value, please note that the value to enter is on KB.