Database login errors in SharePoint event viewer

Question

We are seeing the below error message in SharePoint server event viewer frequently.

"Event ID: 3355 Cannot connect to SQL Server - "ServerName" not found. Additional error information from SQL Server is included below

Connection Timeout Expired. The timeout period elapsed while attempting to consume the pre-login handshake acknowledgement. This could be because the pre-login handshake failed or the server was unable to respond back in time. This failure occurred while attempting to connect to the Failover server. The duration spent while attempting to connect to this server was - [Pre-Login] initialization=2; handshake=1558;[Login] initialization=0; authentication=1; [Post|-Login] complete=10015;"

At the time of the above event viewer error logged, we are seeing below SharePoint hive log.

An error occured while scanning the database, SP2013_Config, for index fragmentation: System.Data.SqlClient.SqlException (0x80131904): Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. ---> System.ComponentModel.Win32Exception (0x80004005): The wait operation timed out at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, SqlDataReader ds) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource1 completion, Int32 timeout, Task& task, Boolean asyncWrite) at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, String methodName, Boolean sendToPipe, Int32 timeout, Boolean asyncWrite) at System.Data.SqlClient.SqlCommand.ExecuteNonQuery() at Microsoft.SharePoint.Utilities.SqlSession.ExecuteNonQuery(SqlCommand command) at Microsoft.SharePoint.Administration.Health.DatabasesAreFragmented.Repair() ClientConnectionId:ad765270-1d33-41cc-8331-af8d9c584cec Error Number:-2,State:0,Class:11 Source: .Net SqlClient Data Provider Server: gcmsql03.krys-global.com StackTrace: at onetnative.dll: (sig=1f46c434-d820-4a5c-8550-b0e8d8318fcd|2|onetnative.pdb, offset=28EE2) at onetnative.dll: (offset=15735)

"User Profile Synchronization service" service account has write permissions on all the databases.

What else could cause this errors? Thanks

Answer 1

The following part of the StackTrace could be interesting: Microsoft.SharePoint.Administration.Health.DatabasesAreFragmented.Repair()

Looks like the Databases used by SharePoint have fragmented indices TimerJob is failing.

This... An error occured while scanning the database, SP2013_Config, for index fragmentation And this... This failure occurred while attempting to connect to the Failover server.

... brings me to the following conclusion:

• You have (or had?) configured a SQL Server Database Mirroring Setup
• SharePoint was also configured to be aware of that Mirroring.
• Now for whatever reason, the Timer-Job tries to connect to the Failover-Server. This connect fails.
• Further thinking:
  • Do you still have a DB-Mirroring Setup? Check that setup with your Database Administrator (or ask for more help on dba.stackexchange.com)
  • Check SharePoint Database-Configuration with the following PowerShell: Get-SpDatabase | select name,legacydatabaseconnectionstring,failoverserver | Out-GridView
  • I think you will find some mismatches between configuration in SQL-Server and SharePoint.