Sql server migration from 2005 to 2012 (110)

Question

hi, experts, 
the database of  .net web form application (Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1025  ) that I am responsible will be migrated to sql server 2012 (110). 
the .net webform use the functions from System.Data.SqlClient. should be ado.net
e.g.
public static DataSet LoadByID(int id)
SqlConnection conn = new SqlConnection();
DataSet ds = new DataSet();
try
conn.ConnectionString = ConfigurationManager.ConnectionStrings["connection_string"].ToString();
conn.Open();
SqlParameter[] aryParams = new SqlParameter[1];
aryParams[0] = new SqlParameter("@ID", SqlDbType.Int);
aryParams[0].Value = id;
SqlCommand cmd = new SqlCommand("a_store_procedure_name", conn);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.AddRange(aryParams);
SqlDataAdapter sqlAdapter = new SqlDataAdapter(cmd);
sqlAdapter.Fill(ds);
catch (Exception ex)
throw ex;
finally
if (conn.State == ConnectionState.Open)
conn.Close();
return ds;
I cloned the database from 2005, restore into 2012 and change the compatibility level to 110 of cloned database.
I am doing tests on the sql server 2012 from the web application user interface. (changed connection string to new 2012 db)
I found that I always hit this error 
any configuration for whole web form application?
Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
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: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
Source Error:
delaynomore.

Answer 1

Hi delaynomore,
According to your description, you fail to execute the function with timeout error after migration to SQL Server 2012. Based on my research, the issue could be due to the long running tasks or uncommitted transactions.
To troubleshoot the issue, besides Olaf's suggestion to check the connection to SQL Server 2012 instance and the stored procedure using SQL Server Management Studio(SSMS) manually, you could also follow the methods below.
1. Execute that procedure manually using SSMS and check if it takes a very long time to execute and return. For example, there could be millions of rows being updated. If it takes a long time, you can adjust the CommandTimeout accordingly.
2. Execute the following statement in SSMS to check if there are any uncommitted transactions: dbcc opentran ('yourDatabaseName'). If there are any uncommitted transactions, please change the  stored procedure accordingly to commit the transactions.
For more information about the process, please refer to the article:
http://blogs.msdn.com/b/spike/archive/2008/07/31/timeout-expired-the-timeout-period-elapsed-prior-to-completion-of-the-operation-or-the-server-is-not-responding.aspx
Regards,
Michelle Li