3.16 Server-Based Application Development

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Every Visual Studio.NET solution will need to interact with server-based resources such as databases, message queues, and event logs. This has often proven difficult in the past since tying together such disparate resources is anything but easy. The early days of ' n' tier or multiple-layer applications as espoused in Microsoft's short-lived Windows DNA strategy were pretty tough due to the difficult process of hooking the technologies together.

As discussed earlier, Visual Studio.NET now comes with a Server Explorer, which lists all of the available server resources in one place. Visual Studio 6.0 had the ability to explore SQL Server and Oracle databases, but this has now been extended to cover most resources you are likely to need. By using the Component Designer and the Server Explorer together server-side components can be created using a drag-and-drop approach.

One of the most commonly used server-side resources is Microsoft Message Queue (MSMQ). This allows messages to be sent from one application to another asynchronously, but with a guarantee that the message will arrive even if the network is down and the message needs to be queued for later submission. While not suitable for every business scenario, it does lend itself well to the disconnected nature of the Internet. MSMQ also provides connectivity to IBM MQ Series, which provides messaging functions across the range of IBM platforms, including AS400 and System 390. The MSMQ component in the Visual Studio Server Explorer allows developers to send and receive messages using a couple of lines of code.

The Windows Event Log is an increasingly useful server resource for developers to use. Although initially designed for use by Microsoft Windows as a way of tracking down errors, the Event Log has now been extended and is the place of choice for Visual Studio.Net developers to write relevant event-related messages from within their applications. Customized event logs can be created and managed if this is more appropriate for a specific application. Events can also be set to trigger pager messages or other tasks.

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