ODAC & C# - TNS: Connect timeout occurred - Connecting only through VS2005 debugger.

Question

I am new to Oracle, and there is an issue I am facing. When I run the application from IDE - Visual Studio 2005, The database connection is established smoothly, but when I run an installed version of the app, the DB connection fails and I get a TNS: Connect timeout occurred error.

I tried with SQLNET.ORA and similar solutions found online, but I could not resolve the issue. I wonder why this happens, since the application running through the IDE and through an installation is on the same PC. I made sure the TNSNAMES.ORA file was correctly edited, and I can connect through an instance of the application running directly on Visual Studio.

public bool connectToDatabase(string dbConnStr)
{
    try
    {
        databaseConnection = dbConnStr;
        OracleConnection dbConn = new OracleConnection(databaseConnection);
        if (dbConn == null)
        {
            CreateDLLLogFiles.ErrorLog(CreateDLLLogFiles.FileName, "Connection object is null");
            return false;
        }
        if (dbConn.State.ToString().Equals("Closed", StringComparison.OrdinalIgnoreCase))
        {
            CreateDLLLogFiles.ErrorLog(CreateDLLLogFiles.FileName, "DB connection - " + dbConn.ConnectionString);
            dbConn.Open();
            return true;
        }
    }
    catch (Exception ex)
    {
        CreateDLLLogFiles.ErrorLog(CreateDLLLogFiles.FileName, ex.Message + "\n" + ex.StackTrace);
        CreateDLLLogFiles.ErrorLog(CreateDLLLogFiles.FileName, "DB String - " + databaseConnection);

        return false;
    }
    return false;
}

The stack trace reads like this:

7/22/2010 6:38:51 PM    ORA-12170: TNS:Connect timeout occurred
   at Oracle.DataAccess.Client.OracleException.HandleErrorHelper(Int32 errCode, OracleConnection conn, IntPtr opsErrCtx, OpoSqlValCtx* pOpoSqlValCtx, Object src, String procedure, Boolean bCheck)
   at Oracle.DataAccess.Client.OracleException.HandleError(Int32 errCode, OracleConnection conn, IntPtr opsErrCtx, Object src)
   at Oracle.DataAccess.Client.OracleConnection.Open()
   at SQL.connectToDatabase(String dbConnStr)

The tnsnames.ora is something like this:

MySource =
  (DESCRIPTION =
    (CONNECT_TIMEOUT=180)(RETRY_COUNT=2)
    (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = TCP)(HOST = 125.63.77.232)(PORT = 1521)))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = MySource )
    )
  )

In the meanwhile, I was being issued a ContextSwitchDeadlock error through the debugger, so I followed instructions and changed the attribute from STAThread to MTAThread on Main(). No more ContextSwitchDeadlock - and Still, the connection issue persists.

I was hoping you could shed some light on the issue - I am close to pulling my hair out. Any insight would be appreciated.

Thanks and Regards, Sreedevi.

Answer 1

Hi Sreedevi,

Can you paste what Connection String you are using, and if possible have the TNSNAMES.ORA, SQLNET.ORA file contents pasted here for diagnosis ?

Thanks, Vivek Juneja

Answer 2

Issue was resolved. Thank you very much for your help, everyone! :) Turned out to be a combination of corrupted ODAC Dlls and then some.

Cheers!