Microsoft Distributed Transaction Coordinator

Microsoft Distributed Transaction Coordinator (MS DTC) coordinates transactions across a network of Microsoft® Windows NT™- and Microsoft® Windows® 95-based systems. With MS DTC, SQL Server can:

• Update data that resides on two or more SQL Server systems.
• Participate in transactions that are controlled by X/Open™ DTP XA-compliant transaction-processing monitors such as Transarc's Encina®, AT&T Global Information Solutions Company's Top End®, and tuxedo®.
• Provide an easy-to-use graphical user interface for distributed transactions.

With MS DTC in SQL Enterprise Manager, you can:

• Start and stop MS DTC (as a Windows NT service).
• Open the DTC Transactions window, where you can view all transactions that are running and the status of each transaction. You can force prepared transactions to resolve as being committed or to stop. You can force active transactions to stop. You can also force a coordinating MS DTC server to remove a transaction from its log.
• Open the DTC Trace window, where you can view event log information as well as MS DTC trace information. You can filter the displayed information by severity level.
• Open the DTC Statistics window, where you can view statistics about MS DTC counters, including:
  • Current number of active transactions
  • Peak number of concurrent transactions
  • Number of committed transactions
  • Number of aborted transactions
  • Number of in-doubt transactions
  • Number of administratively resolved transactions
  • Total number of transactions processed
  • Transaction response times
  • The date and time the MS DTC session started
• Open the DTC Configuration window, where you can set MS DTC update frequency, transaction display retention, log file location, and checkpoint and flush timers.

MS DTC is installed when SQL Server 6.5 is installed. The MS DTC service is added to the Services application in Control Panel.

    To use MS DTC from SQL Enterprise Manager

1. In the Server Manager window, select a server and expand the tree for that server.

   A Distributed Transaction Coordinator icon appears under the name of the server if that server has MS DTC installed.

2. To start, stop, or administer MS DTC, click the right mouse button on the Distributed Transaction Coordinator icon.
3. From the shortcut menu, select the appropriate command.

You can also use MS DTC by using the Distributed Transaction Coordinator command from the Server menu.

For more information about configuring and using MS DTC, see the Guide to Microsoft Distributed Transaction Coordinator.