Sitecore Log File Repeated Error

I have a sitecore 7.2 site and it is upgraded from 6.6, Any ideas what cause the following error to be appears many times in log file:

ManagedPoolThread #3 2015:07:14 10:03:48 ERROR Exception occurred in retryer scope :
   at System.Environment.GetStackTrace(Exception e, Boolean needFileInfo)
   at System.Environment.get_StackTrace()
   at Sitecore.Data.DataProviders.Retryer.ExecuteNoResult(Action action, Action recover)
   at Sitecore.Analytics.Automation.Data.Sql.SqlAutomationProvider.GetDueStates(AutomationStatesDataTable dataTable, Int32 maxEntries)
   at Sitecore.Analytics.Automation.AutomationWorker.GetDueStates(AutomationStatesDataTable dataTable)
   at Sitecore.Analytics.Automation.AutomationWorker.Process()
   at Sitecore.Analytics.Automation.AutomationWorker.<Wakeup>b__4(Object state)
   at Sitecore.Threading.ManagedThreadPool.ProcessQueuedItems()
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()

Solution

The exception you see is thrown when the Analytics database connection string is incorrect.

Try to connect to the database using SQL Server Management Studio using credentials from this connection strings.

It is displayed multiple times because of Retryer which tries to re-execute the query after failing (see Jason Home answer for more detailed explanation of retryer).