Testing Design Assumptions
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
During the design process, the design team makes assumptions that are incorporated into the Active Directory design, such as Active Directory replication and application compatibility. After the team completes a preliminary draft of the design, it must prove these assumptions in the lab environment.
To test the design assumptions in the lab environment, the design team must:
Analyze Active Directory replication site topology.
Develop a test plan, and then test application and desktop compatibility.
Analyze Active Directory Replication and Site Topology
The site topology design specifies the maximum replication latency. This is the length of time that is required to replicate changes throughout the forest. The design team must make sure that forest-wide replication latency is less than or equal to the maximum replication latency specified in the design. The team must perform a worst-case test that is based on the maximum number of hops that are assumed in the design. The team must observe the time that is required for replication convergence when a domain controller or communications link fails.
To analyze Active Directory intersite replication site failover
Identify the domain controllers that are responsible for intersite replication by using Active Directory Sites and Services.
Disconnect domain controllers or disable communications links that are used in intersite replication.
Allow the Knowledge Consistency Checker (KCC) to automatically configure new replication topology.
Identify the domain controllers that are now responsible for intersite replication.
Reconnect the domain controllers or enable communications links.
Verify that the intersite replication topology returns to the original state, as identified in step 1.
Verify Application and Desktop Compatibility
The design team must also determine the compatibility between applications, desktop operating systems, and Active Directory. Typically, the aspects of application testing that are affected by an Active Directory migration or upgrade include applications that run on servers and client computers, in addition to remote access usage.
Verify the application and desktop compatibility design assumptions by creating a list of all critical applications. Have design team members test each application to make sure that it operates correctly in a migrated environment.
When you verify application and desktop compatibility, verify that:
Existing server applications, such as those that currently run on a Windows NT 4.0 backup domain controller (BDC), can run on Windows Server 2003–based member servers and domain controllers.
For example, some server applications that run on BDCs take advantage of Shared Local Groups. To run these server applications on a Windows Server 2003–based domain controller, verify that the applications run correctly by using Active Directory domain local groups.
Server applications that run on a mixture of Windows Server 2003–based and Windows NT 4.0–based servers can interoperate with one another.
For example, verify that a Windows Server 2003–based server running Microsoft® SQL Server™ can interact with a Windows NT 4.0–based server running the same application.
Existing desktop applications run correctly when the domain infrastructure is migrated to Windows Server 2003 Active Directory.
Existing applications that use integrated Windows security run correctly when the domain infrastructure is migrated to Windows Server 2003 Active Directory.
If you find that a server application cannot be migrated to a Windows Server 2003–based domain controller, you can try to reinstall the application or a later version of the application on a Windows Server 2003–based member server. If the application cannot run on a server that runs Windows Server 2003, you can continue to run the application on the server that runs Windows NT 4.0 or Windows 2000.
Provide feedback to the design team that the server application's domain cannot be upgraded in-place or consolidated and must remain until a version of the application that can run on a Windows Server 2003–based domain controller is available. As a long-term deployment goal, transition any applications that currently run on domain controllers to member servers.