FIX: XA Transaction Monitors May Show Inconsistent Outcome

ID: Q232343

The information in this article applies to:

Microsoft Transaction Server 2.0

SYMPTOMS

Other database's XA monitor (eg. Oracle XA monitor, DB2 XA monitor) may show indoubt transactions that were never resolved by Distributed Transaction Coordinator (DTC) XA Transaction Manager (XATM)

CAUSE

DTC's XATM recovery code issues xa_recover() call to the Resource Manager (RM), which returns XAER_RMERR. DTC incorrectly treats recovery as successful and deletes the information about the RM. This can cause DTC to forget about transactions that are still indoubt in the Resource Manager. This problem only occurs with 1-pipe RMs. DTC has two models for supporting XA transactions:

1-pipe model: where the prepare and commit are sent on the application pipe/connection to the RM

2-pipe model: where DTC opens a separate connection to the RM and sends prepare/commit on this second pipe.

NOTE: Oracle and DB2 Resource Manager uses the 1-pipe model.

RESOLUTION

This hotfix(ID: 051099e) fixes the DTC's XA transaction manager, to not ignore the return code from xa_recover() in 1-pipe model.

STATUS

Who Should Install This Release

You should install hotfix 051099e if you are noticing the above mentioned behavior.

Installation:

This hotfix should only be installed on systems running Microsoft Windows NT version 4.0 (Service Pack 5). It should not be installed on other systems running Microsoft Windows NT version 3.51 or Microsoft Windows 2000.

Note that this hotfix is based on the version of Microsoft DTC included with the Windows NT 4.0 Service Pack 5 release. By installing this hotfix, you are upgrading Microsoft DTC to the Windows NT 4.0 Service Pack 5 release level in addition to correcting the problems described here.

How to Install on a Non-clustered System

Create an empty temporary directory on your system.

Run the self-extracting executable file (i051099e.exe (i386) or a051099e.exe (alpha)) and type the name of the temporary directory when you are prompted to do so. The program unzips the following files into the temporary directory:
```
   Dtcsetup.exe
   Qfe051099e.txt 
```
Stop the Microsoft DTC Service, if it is running. Stop all services that depend on Microsoft DTC (including Microsoft Transaction Server, Microsoft SQL Server, Microsoft Message Queue, and Microsoft COM Transaction Integrator (COMTI)).

Close the Windows NT Control Panel, if it is open.

Run Dtcsetup.exe.

Restart the system.

Restart all services that depend on Microsoft DTC.

How to Install on a Cluster with an Already Clustered Microsoft DTC

Create an empty temporary directory on both nodes of the cluster.

Run the self-extracting executable file (i051099e.exe (i386) or a051099e.exe(alpha)) on both nodes of the cluster and type the name of the temporary directory when you are prompted to do so. The program unzips the following files into the temporary directory:
```
   Dtcsetup.exe
   Qfe051099e.txt 
```

Use the MSCS Cluster Administrator to stop the Microsoft DTC cluster resource, if it is running. Stop all services that depend on Microsoft DTC (including Microsoft Transaction Server, Microsoft SQL Server, Microsoft Message Queue, and Microsoft COMTI).

Close the Windows NT Control Panel on all systems in the cluster.

Run Dtcsetup.exe on the node that controls the Microsoft DTC cluster resource. When you are prompted to install Microsoft DTC on the other nodes in the cluster, run Dtcsetup.exe on those nodes.

Restart all systems.

Restart all services that depend on Microsoft DTC.

How to Install on a Cluster with a Non-clustered Microsoft DTC

Create an empty temporary directory on both nodes of the cluster.

Run the self-extracting executable file (i051099e.exe (i386) or a051099e.exe (alpha)) on both nodes of the cluster and type the name of the temporary directory when you are prompted to do so. The program unzips the following files into the temporary directory:
```
   Dtcsetup.exe
   Qfe051099e.txt 
```

Stop the Microsoft DTC Service on all systems in the cluster. Stop all services that depend on Microsoft DTC (including Microsoft Transaction Server, Microsoft SQL Server, Microsoft Message Queue, and Microsoft COMTI).

Close the Windows NT Control Panel on all systems in the cluster.

When you install this release on a clustered system, the Setup program automatically installs a clustered version of Microsoft DTC. The clustered version of Microsoft DTC requires an MSCS Resource Group that contains both a Network Name Resource and a Shared Disk Resource. Before installing this release, ensure that at least one such MSCS Resource Group exists. Dtcsetup.exe will assign Microsoft DTC to the first MSCS Resource Group that it finds that contains both a Network Name Resource and Shared Disk Resource. After ensuring that the necessary Resource Group exists, run Dtcsetup.exe on the node controlling that Resource Group.

When you are prompted to install Microsoft DTC on the other nodes in the cluster, run Dtcsetup.exe on those nodes.

Reboot all systems.

Restart all services that depend on Microsoft DTC.

Additional query words:


Keywords          : kbDTC kbMTS kbMTS200fix 
Version           : winnt:2.0
Platform          : winnt 
Issue type        : kbbug

Last Reviewed: June 22, 1999