Recently,After the Path Tuesday, None of the clients which are reporting to Primary Site did not perform a successful Scan (clients beneath secondary Site are working Good) .This leads me to look at the software update logs on the client to see what is going wrong. Since most of the clients directly reporting to Primary are having issues ,so thought of checking/troubleshoot this issue on the Primary site itself .
Browse through the wuahandler.log from Drive:\Configmr\SMS_CCM\Logs,below is what I can see.
OnSearchComplete - Failed to end search job. Error = 0x80244022.
Scan failed with error = 0x80244022.
Same as HTTP status 503 - the service is temporarily overloaded.
Source: Windows Update Agent
The 503 Service Unavailable error means, the problem is usually with the web site is down which is WSUS in this case.
Tried restarting the server ,followed by WSUS service and IIS service but issue still exist.
after the search on the internet,found this article ,leads me to check the application pool in IIS.I jump into IIS to check the status of WSUS application pool which was in stopped state .
After starting the wsuspool application,sync completed successfully.
Tried to initiate software update scan cycle on the client,monitor wuahandler.log
so why does the WSUS pool in IIS stopped ? that could be because of memory limit.take a look at these blogs http://blogs.technet.com/b/configurationmgr/archive/2015/03/23/configmgr-2012-support-tip-wsus-sync-fails-with-http-503-errors.aspx and http://blog.coretech.dk/kea/house-of-cardsthe-configmgr-software-update-point-and-wsus/
Hope it helps!