COM+ Components

We've already talked about how COM+ can manage and control our transactions, and how it can tell the resource manager to set about undoing database changes when a transaction is aborted – and we've even seen a couple of examples that use this facility.

But (as we've also mentioned), COM+ does a whole lot more than that. So in this final section, we'll take a quick look at some of the other facilities that Microsoft have built into COM+ – facilities which are now an integral part of the Windows 2000 operating system. As we'll see, COM+ is really an all-round management system for the components that we use in our applications.

Finally, we'll complete our short discussion on components and transactions by returning to our Internet Banking scenario once more. We'll rewrite the cash transaction problem one last time, drawing together the techniques of componentization and transactional processing, and using COM+ to manage both of these aspects.

We don't intend to give a complete introduction to COM+ here – indeed, the expanse of COM+ as a subject easily justifies the many books that do and will exist on COM+. But we will meet Component Services, and see how Microsoft has given us a platform for our transactional and componentization ideas to fit naturally together.