COM Services in Perspective

 

Chapter 18 - COM+ Services
bySimon Robinsonet al.
Wrox Press 2002

  

COM+ Services in Perspective

In the bad old days of programming, the application developer had to build everything from scratch. If the developer wanted database functionality, for example, then they would have to implement it, devising a mechanism for maintaining indexes and searching for records through flat files. In those freewheeling frontier days of software engineering, people wasted a lot of time re-inventing the wheel.

As the programming techniques evolved, vendors packed useful functionality into reusable server components . As time went on, more and more useful functionality was pressed downward out of application programs and into the level of server programs, and even the operating system.

COM+ Services make life easier for enterprise developers by providing valuable functionality that their components can easily employ . When a component needs a capability such as transaction enforcement, the developer can rely on COM+ Services to provide a robust solution.

Firstly, let's take a quick look at the COM+ programmer's best friend: the Component Services "snap-in".

The Component Services Snap-In

Seasoned developers may recall that the MTS administrator was accessed from the Windows NT Option Pack option on the Start menu. In keeping with its new status as an integral part of the operating system, COM+ Services is listed more prominently on the Administrative Tools menu in Windows 2000, under the title Component Services .

The left pane of the Component Services window contains a hierarchical tree with computer, COM+ application, and component nodes. (In the parlance of Component Services, an application is a group of COM+ components that are administered as a whole; this was called a package in MTS.) Each component class in an application is represented by a golden sphere with a plus sign in the middle; the sphere spins when the component is being accessed.