I have an application that never had issues on SQL Server 2012, but now it occasionally crashes when trying to access SQL Server 2019 on startup.
Here is the event log:
Application: MyApplication.exeFramework Version: v4.0.30319Description: The process was terminated due to an unhandled exception.Exception Info: System.ComponentModel.Win32ExceptionException Info: System.Data.SqlClient.SqlException at System.Data.SqlClient.SqlInternalConnectionTds..ctor(System.Data.ProviderBase.DbConnectionPoolIdentity, System.Data.SqlClient.SqlConnectionString, System.Data.SqlClient.SqlCredential, System.Object, System.String, System.Security.SecureString, Boolean, System.Data.SqlClient.SqlConnectionString, System.Data.SqlClient.SessionData, System.Data.ProviderBase.DbConnectionPool, System.String, Boolean) at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(System.Data.Common.DbConnectionOptions, System.Data.Common.DbConnectionPoolKey, System.Object, System.Data.ProviderBase.DbConnectionPool, System.Data.Common.DbConnection, System.Data.Common.DbConnectionOptions) at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(System.Data.ProviderBase.DbConnectionPool, System.Data.Common.DbConnection, System.Data.Common.DbConnectionOptions, System.Data.Common.DbConnectionPoolKey, System.Data.Common.DbConnectionOptions) at System.Data.ProviderBase.DbConnectionPool.CreateObject(System.Data.Common.DbConnection, System.Data.Common.DbConnectionOptions, System.Data.ProviderBase.DbConnectionInternal) at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(System.Data.Common.DbConnection, System.Data.Common.DbConnectionOptions, System.Data.ProviderBase.DbConnectionInternal) at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(System.Data.Common.DbConnection, UInt32, Boolean, Boolean, System.Data.Common.DbConnectionOptions, System.Data.ProviderBase.DbConnectionInternal ByRef) at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(System.Data.Common.DbConnection, System.Threading.Tasks.TaskCompletionSource`1<System.Data.ProviderBase.DbConnectionInternal>, System.Data.Common.DbConnectionOptions, System.Data.ProviderBase.DbConnectionInternal ByRef) at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(System.Data.Common.DbConnection, System.Threading.Tasks.TaskCompletionSource`1<System.Data.ProviderBase.DbConnectionInternal>, System.Data.Common.DbConnectionOptions, System.Data.ProviderBase.DbConnectionInternal, System.Data.ProviderBase.DbConnectionInternal ByRef) at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(System.Data.Common.DbConnection, System.Data.ProviderBase.DbConnectionFactory, System.Threading.Tasks.TaskCompletionSource`1<System.Data.ProviderBase.DbConnectionInternal>, System.Data.Common.DbConnectionOptions) at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(System.Data.Common.DbConnection, System.Data.ProviderBase.DbConnectionFactory, System.Threading.Tasks.TaskCompletionSource`1<System.Data.ProviderBase.DbConnectionInternal>, System.Data.Common.DbConnectionOptions) at System.Data.SqlClient.SqlConnection.TryOpenInner(System.Threading.Tasks.TaskCompletionSource`1<System.Data.ProviderBase.DbConnectionInternal>) at System.Data.SqlClient.SqlConnection.TryOpen(System.Threading.Tasks.TaskCompletionSource`1<System.Data.ProviderBase.DbConnectionInternal>) at System.Data.SqlClient.SqlConnection.Open() at System.Data.Common.DbDataAdapter.FillInternal(System.Data.DataSet, System.Data.DataTable[], Int32, Int32, System.String, System.Data.IDbCommand, System.Data.CommandBehavior) at System.Data.Common.DbDataAdapter.Fill(System.Data.DataTable[], Int32, Int32, System.Data.IDbCommand, System.Data.CommandBehavior) at System.Data.Common.DbDataAdapter.Fill(System.Data.DataTable) at MyApplication.Program.MyDatabaseMethod(System.String) at MyApplication.Program.Main(System.String[])Here is the method that it crashes on:
public static string MyDatabaseMethod(){ DataTable dt = new DataTable(); string query = "SELECT TOP 1 col1 FROM mydatabase.dbo.mytable"; SqlDataAdapter da = new SqlDataAdapter(query, myConnectionString); da.Fill(dt); string data = dt.Rows[0].Field<string>("col1"); return data;}This works 90% of the time, but the occasional crash is becoming problematic. Does the error look like a timeout? The database is very busy and has multiple instances (~20) of this application connecting at the same time each night, so I am wondering if there is some concurrency issue with that many logins at once. The query itself is accessing a table with no more than 30 rows.