Active Directory has come a long way since its introduction with Windows 2000 in 1999. Of course, the Exchange community will tell you that AD is simply the old Exchange Directory Store (DS) as used in Exchange 4.0 through 5.5. There’s a lot of truth in this because the Exchange DS set down many of the fundamentals still seen in AD, such as the use of the Extensible Storage Engine (ESE) as its database engine.
In any case, Exchange 2000 embraced Active Directory and became Microsoft’s first true enterprise-capable application. There were enterprise-class deployments of Exchange before Exchange 2000, but more like a loose collection of federated sites than the closely-coupled organization that we still use today.
I worked for Compaq at the time and managed an Advanced Technology Group whose mission was, in part, to find out just how scalable technology like Active Directory was. We set up a small team in the European Technical Centre in Sophia-Antipolis (near Nice, France) to run some tests involving loading the complete U.S. phone book into the directory. As I remember, the phone directory for each state was available on one or more CDs and some code was written to load the 100 million or so entries for phone subscribers into Active Directory via LDIF. Despite the relative slowness of the hardware available at the time, the load went well and access to the directory via LDAP and other tools was pretty fast. The only real issues that were encountered was when another domain controller was added and the server that had been used for the initial load began to replicate the directory to the new controller, a process that can only be described as glacially slow. I think that replication eventually completed about two weeks after beginning.
Of course, Active Directory has moved ahead enormously since 1999. It’s much easier to recover deleted objects, management is a well-known art rather than black science, and the availability of much more capable networks has made replication problems an exception rather than a common condition. Development continues to produce new features such as read-only domain controllers, even if applications such as Exchange choose to ignore them.
All of this brings me to the announcement from Brian Desmond that he has completed an update for his book “Active Directory: Designing, Deploying, and Running (4th edition)”. The new edition is now in the hands of Brian’s editors, who no doubt will do a splendid job of turning his text into prose that leaps off the page, or at least explains the murkier details of how Active Directory works. Apparently the new book should be available in March 2013, but as always, there’s a heap of things to be done to get a book from author text into printed pages. To make sure that you get your copy as soon as possible, you can pre-order the new (5th edition) book now.
Brian’s a good guy and he knows his stuff. If you haven’t bought a book to shore up your knowledge about Active Directory, you should buy his book. Absolutely recommended.
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