FIX: MS DTC/MTS Errors Cause "Ora-00000 Normal, Successful Completion" Messages (254675)

SYMPTOMS

When a Microsoft Transaction Server (MTS) or Microsoft Distributed Transaction Server (MS DTC) application encounters errors that are MTS-related or MS DTC-related, only the following error message is returned to the application:

DIAG [NA000] [Microsoft][ODBC driver for Oracle][Oracle]ORA-00000: normal, successful completion (0)

This error message is misleading in an environment that uses MTS and MS DTC because it masks the location of the true error and prevents useful error messages from being returned to the application.

CAUSE

With the current releases of the Oracle ODBC driver (MSORCL32.DLL) and the MTS/OCI layer (Mtxoci.dll), error messages that are generated by the underlying MS DTC/MTS layer are not correctly trapped by the Oracle ODBC driver.

The driver incorrectly assumes that the Mtxoci.dll file is reporting only Oracle errors, and the driver checks the Errors collection for the Oracle connection to retrieve error information. Because there are no Oracle errors, the only error message to return is the "normal, successful completion" error message.

RESOLUTION

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next Microsoft Data Access Components service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English version of this fix should have the following file attributes or later:

   Date      Version        Size             File name     
   --------------------------------------------------------
   02/14/00  02.573.5014    138,512 bytes    Msorcl32.dll
   03/04/00  1999.6.904     87,312 bytes     Mtxoci.dll

MORE INFORMATION

Steps to Reproduce the Behavior

Configure the Oracle database server to accept only a limited number of client connections, such as 15 or 20. This can be done by modifying the Processes parameter in the Init sid.ora file. Then, stop and restart the Oracle service.
Use Visual Basic to create an ActiveX DLL with one method. Within this method, create an ADO connection to an Oracle database by using the Microsoft ODBC for Oracle driver, create a simple recordset that selects a few records from any table, and then close the recordset and the connection.
Compile this DLL and register it under MTS. Mark the DLL as "Requires a New Transaction."
Create a client application that creates an instance of the new object, and calls the single method in a loop of about 10 times.
Compile this client application to an .exe, and then launch approximately 10 instances of it.
Notice that some instances of the client application encounter errors when attempting to connect to the Oracle server. Several of the returned errors are the Ora-00000 "Normal, successful completion" errors.