Active Directory Services Directory Services

Active Directory Services Directory Services What are Directory Services? The concept of a Directory Service is that of distributed system services architecture that provides references by name or function to specific attributes, applications and other systems and services throughout an operating system (Bernstein, 1996). It provides the necessary definitions of integration points, process and order state routings for application completion, in addition to data structure and services integrations throughout an operation system (Rednic, Toma, 2009).

How are Directory Services implemented in various operating systems? As they are essential for an operating system to function, Directory Services are defined at the file system level (Rednic, Toma, 2009). Responsible for validating data accuracy with file systems, data replication and data distribution, Directory Services also complete operating system file-based mirroring and backup to ensure fault tolerance of the system as well.

In operating systems designed for distributed processing and support of multiple instances of enterprise-wide applications Directory Services include a namespace for each location or application instance (Chen, Chen, Maa, 2002). The namespace functions as an area where the local administrator for the specific enterprise instance completes new installs, upgrades, and manages integration tasks and workflows with other namespace areas throughout the operating system-based network and enterprise wide.

Namespaces are also specifically designed to allow for administrators to create a federated system that can scale across all instances of an enterprise application, which is often an Enterprise Resource Planning (ERP) system (Chen, Chen, Maa, 2002). In this scenario, Directory Services are the catalyst for providing ERP systems with cross-department and cross-divisional integration to ensure supply chains stay coordinated, sales orders get fulfilled, and services for customers get delivered. These set of enterprise needs were specifically what Microsoft defined their Active Directory Services architecture to meet.

Included in the Active Directory are a series of technologies for ensuring more efficient use of enterprise applications globally by companies who have dozens of namespaces or domain locations. Active Directory Services include the Lightweight Directory Access Protocol, Microsoft-designed Kerberos authentication, support for legacy Domain Naming Service (DNS) directory services and the option of consolidating name spaces through domain and interdomain trust relationships to support legacy Windows NT Server implementations (Pleas, 1999).

Microsoft chose to support domain and interdomain naming services and interdomain trust as they have nearly 2 million installed Windows NT server enterprise servers running globally and Active Directory Services is a path for upgrade to .NET and future operating systems. In conclusion, Directory Services are implemented within operating systems at the file system level to ensure a high degree of data synchronization, interprocess coordination, and fault tolerance as system-level files are duplicated and stored to ensure system redundancy and security.

What are the advantages / disadvantages of utilizing directory services? Are there alternatives? The advantages of directory services being used in enterprise deployments of operating systems include more flexibility in defining user accounts, greater options for defining role-based access to various databases and systems through the network, a reduction in network traffic, and more efficient means of managing legacy systems and databases. Directory Services also enable more effective management of interdomain trust and domain integration through Active Directory Replication (ADP) systems.

Both ADP and enterprise replication are processes that are critical to having an enterprise-wide system perform at an optimal level (Chen, Chen, Maa, 2002). The disadvantages of using Directory Services are the costs associated initially for creating and keeping them current, the need to have a staff of engineering and software experts on-hand to add functionality to the system as needed, and the complexity of integration across different Directory Services architectures at the operating system level.

Directory Services can be extremely complex and when used for role-based access within enterprises, can lock employees out of their own files and systems and the ones they need to use for their jobs as well if only a slight variation is made in the security levels of the users. There is also the downside risk of technology obsolescence as many companies will standardize on a vendors' specific version fo Directory Services, only to find their company moving in an entirely different direction over time.

The risk of incompatibility to other systems from suppliers, partners, and buyer or customers' systems is also significant. This is especially the case in enterprise systems that often rely on hundreds of namespaces on the same network, and the coordination of application instances across each one (Chen, Chen, Maa, 2002). Finally the complexities of licensing across Directory Services implementations can be very expensive and also very complex, especially for Microsoft Active directory Services (Pleas, 1999).

What disaster recovery options are available for Directory Services? The basic nature of a Directory Service is to replicate content and files to ensure fault tolerance and redundancy over time. The use of namespaces for fault tolerance has also been incorporated into specific variations of the UNIX operating system (Thibodaux, 2005). Directory Services vary in their approach to backing system configuration data and fault tolerant.