The distributed transaction coordinator (DTC) is a Windows subsystem that enables transactions to be coordinated across multiple machines. These transactions may be database transactions, although DTC also supports other transaction types which are outside the scope of this discussion.

AppClarity 5.0 requires, for the first time, that DTC is enabled both on the machine on which the AppClarity service is running and the database server, but only if the database server is on a different machine to the machine running the AppClarity service.

Failing to configure DTC appropriately will result in the AppClarity service failing to start and logging a configuration message to indicate the problem. DTC must also be allowed through the firewall on the application server.

Enabling DTC

To enable DTC:

  1. On the Windows server (for both the AppClarity service and database service) run the dcomcnfg (Component Services) utility.
  2. In the Component Services dialog, expand the Component Services tree.
  3. Expand My Computer under Computers.
  4. Expand Distibuted Transaction Coordinator.

  5. Right-click Local DTC, and from the context menu, choose Properties.
  6. In the Local DTC Properties dialog, click the Security tab.

  7. Under Security Settings, check Network DTC Access.
  8. Under Transaction Manager Communication, check both Allow Inbound and All Outbound.
  9. Check Enable XA Transactions.
  10. Click OK.