COM & .NET Component Services

In-Doubt Transactions

Sometimes COM+ (actually, the DTC) is unable to decide on the fate of a transaction. This indecisiveness is usually the result of some unexpected catastrophe. One possible catastrophe is network failure after the root object is deactivated, but before the DTC could conduct the two-phase commit protocol with remote resource managers. Another possible catastrophe is when a resource manager’s machine crashes in the middle of the two-phase commit protocol. In those cases, the transaction is said to be in-doubt. COM+ cannot decide on the fate of in-doubt transactions. It is up to the system administrator to manually resolve those transactions, using the Component Services Explorer. COM+ lists the in-doubt transactions under the DTC folder, on the Transaction List pane. An in-doubt transaction has the comment (In Doubt) in its status column. The system administrator should right-click on the in-doubt transaction and select Resolve from the pop-up menu. COM+ offers three options to resolve a transaction: Commit, Abort, or Forget (see Figure 4-15).

Figure 4-15. Resolving in-doubt transactions

When the administrator selects Commit or Abort, COM+ instructs all accessible resource managers that took part in the transaction to commit or abort, respectively. Later on, when the rest of the resource managers become available, your system administrator should use an administrative ...