title: Strange intermittent SQL connection error, fixes on reboot, comes back after 3-5 days (ASP.NET)
body: <p>For some reason every 3-5 days our web app loses the ability to open a connection to the db with the following error, the strange thing is that all we have to do is reboot the container (it is a VPS) and it is restored to normal functionality. Then a few days later or so it happens again. Has anyone ever had such a problem? I have noticed a lot of ANONYMOUS LOGONs in the security log in the middle of the night from our AD server which is strange, and also some from an IP in Amsterdam. I am not sure how to tell what exactly they mean or if it is related or not.</p>
  
  <pre><code>Server Error in '/ntsb' Application.
  A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)
  Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
  
  Exception Details: System.Data.SqlClient.SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)
  
  Source Error:
  
  Line 11:        
  Line 12:        
  Line 13:        dbConnection.Open()
  Line 14:        
  Line 15:        
  
  
  Source File: C:\Inetpub\wwwroot\includes\connection.ascx    Line: 13
  
  Stack Trace:
  
  [SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)]
     System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +248
     System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +245
     System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, SqlConnection owningObject) +475
     System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject) +260
     System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart) +2445449
     System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) +2445144
     System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) +354
     System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) +703
     System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) +54
     System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) +2414696
     System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) +92
     System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) +1657
     System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +84
     System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +1645687
     System.Data.SqlClient.SqlConnection.Open() +258
     ASP.includes_connection_ascx.getConnection() in C:\Inetpub\wwwroot\includes\connection.ascx:13
     ASP.default_aspx.Page_Load(Object sender, EventArgs e) in C:\Inetpub\wwwroot\Default.aspx:16
     System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +25
     System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +42
     System.Web.UI.Control.OnLoad(EventArgs e) +132
     System.Web.UI.Control.LoadRecursive() +66
     System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2428
  
  
  Version Information: Microsoft .NET Framework Version:2.0.50727.3053; ASP.NET Version:2.0.50727.3053 
  </code></pre>