Wsus not updating all clients
Other customers said the Windows Update agent didn’t perform a successful scan and reported these errors in the In common for all customers was that the WSUS App pool stopped.
When starting the IIS WSUS App pool back, most clients downloaded 5-10 MB. Clients looked to be downloading the full catalog from the SUP which was the reason why one customer saw the high utilization of their MPLS lines.
Recently I have seen that happen at several customers. At almost the same time the WSUS IIS App pool chrased and stopped.
Starting the IIS pool up again would once again flood the MPLS line, run for a few minutes and crash again.
This approach provides a fresh start with a new Windows Update data store if the file is corrupted.
when the software update scan cycle initiated, Windows update agent (windows update service) will contact WSUS (SUP) for scanning and if is successful,a state message will be sent to site server confirming that,software update scan is completed successfully which can be seen from this log.This randomization prevents all software update clients from starting update installations at the same time (This setting is disabled by default).More info,read Required: This means the software update is applicable but is not yet installed.Get the report to know the software update scan results from If software update scan is successful from ,you can ignore this log file and directly move to next log (updatesdeployment.log) .If Software update scan is not successful then,you should look at this log for more information.