1. What is Windows DNA?

Windows DNA is the set of architecture guidelines to create distributed systems using Microsoft technologies.

For more: http://msdn.microsoft.com/developer/dna/dnaovervw.htm

2. What services DNA provides?

DNA includes three main services: COM+ - Component services, MSMQ – Messaging services, IIS – Web application services.

3. What are main promises for COM+?

• Bring your own transaction
• Expanded Security
• Centralized Administration
• In-Memory Database
• Queued Components.
• Event Notification
• Load balancing

1. Does DNA have provisions for integration with IBM mainframes?

Yes! Using Microsoft’s COM Transaction Integrator (TI), application developers can extend and expose CICS and IMS transaction programs through the use of COM components.

For more: http://www.microsoft.com/sna/

2. How will you get data in DNA?

Distributed interNet Applications Architecture is designed to solve problems in developing enterprise internet systems.

In Microsoft Professional Developers Conference ’98 DNA was clearly defined as being made up of three technological areas: Forms+, COM+, and Storage+.

Each of these areas corresponds to one of the N tiers. Forms+ are those products designed to support the client tier, primarily DHTML, XML, and various rich client technologies. COM+ are those products designed to support the middle tier. And Storage+ are those products designed to support the data tier, primarily SQLServer7.0 and third party databases through Universal Data Access (OLE DB, ADO)

• The most important feature of DNA is scalability. Scalability is particularly important in a Web environment, where popular sites can attract thousands of visitors per day. It’s a lot harder to plan capacity in this environment than on a local area network with a fixed number of users and a stable traffic pattern.
• Lower cost of ownership through the Zero Administration for Windows initiative, where the Active Directory service controls how and when applications are installed on network clients, provides information about their use, and repairs them automatically if they get ‘broken’.
• Transparent internal/external network connectivity, so that the Internet simply becomes an extension of the local network of Intranet.
• A better ‘disconnected’ environment for mobile computer users, so that-for example-laptop users can connect when appropriate but still have all the necessary features available when they are not connected to the office network
• Dynamic component utilization using a new technology called interception that allows components to change their behavior dynamically as their environment changes.

The goal in making demo is to show some capabilities of current technologies that are part of toolkit for DNA implementation.

Implementation of Forms+ will use HTML and VB Script. Client data access will be performed by RDS (Remote Data Service). RDS requires Microsoft IE 4 browser.

Implementation of COM+ tier will include DCOM with MTS (Microsoft Transaction Server. I contemplated to use MSMQ (Microsoft Message Queue) to show asynchronous processing but it drastically complicates Demo application. For Internet integration Internet Information Server and Active Server Pages (ASP) are used.

SQLServer6.5 implements Storage+.

The main idea of Demo application is taken from [3]. It was modified to fit to my goals, available resources and available time.

[1] Microsoft related sites

Microsoft COM Technologies http://www.microsoft.com/com/

Windows DNA Building Windows Applications for the Internet Age http://msdn.microsoft.com/developer/dna/windnawp.htm

Microsoft Remote Data Service Web Page http://www.microsoft.com/data/ado/rds/

Microsoft Web Services http://www.microsoft.com/ntserver/nts/web/

[2] Past Issues of ObjectWatch Newsletter http://www.objectwatch.com/past.htm

[3] Alex Homer and David Sussman, "Professional MTS MSMQ with VB and ASP"