One of my friend has upgrade one of its content in Sharepoint Farm, Basically he was using the SQL Server 2008 R2, trial on his SharePoint Farm 2010. He upgradeto SQL Server 2008 R2 Etnerpriese Edition, he did that successfully but when he restart the farm server, he found that all the sharpeoint Server went down. He opened that Central administration, he got the error that Service is not available, Following error reported to the event viewer.
An exception occurred when trying to issue security token:The HTTP service located at http://WebServer-Win:32843/SecurityTokenServiceApplication/securitytoken.svc/actas is too busy,
Reason: Follwoing app pool were stop due to farm administrator credentials,
SharePoint Central Administration v4
SharePoint – 80
Provide the administrator credential and start the app- pool again. and SharePoint again start work.
I would recomend to check the following if sharpeoint working stop instant.
(1) Check the 14 hives logs imidiately.
(2) Space on the Server (should always be double).
(3) SharePoint Foundation Services, with SqLServer Services on deployed farm.
(4) Check the Inetmgr (IIS) SharePoint Web applicaitn are started or not, they may stop if there any credeantial change of Farm Administrator, because on the back end there are SharePoint Timer services.
–Hope this article is helpful.