Lessons Learned from Eric Fleischman ~ My blog about Active Directory and everything else

Wednesday, April 22, 2009

Lessons Learned from Eric Fleischman

As previously mentioned I attended the Philly.NET users group Code Camp on Saturday 4/18/2009.

I had the great privilege to sit through two sessions from Eric Fleischman.

Who is Eric Fleischman you ask?

Eric is currently the Dev Lead for Virtualization(cloud services) at Microsoft. Eric has also been a lead developer on the AD team for Microsoft. When it comes to those that know AD the best there is no debate...Eric makes that list.

One of Eric's best known projects in the AD community was creating the largest Active Directory known to date.

What I wanted to do is list some of the things I picked up.

    • Always make every DC a GC, assume you can do that unless you can prove that your bandwidth can't handle it. In most environments the DC/GC role will be fine. We already do this where I am but I was glad to hear Eric recommend it.
    • Leave Field Engineering Logging on everywhere. Turning it on won't hurt perf and the info you get from it is very valuable. It will let you know about inefficient and expensive queries in your environment. More info on field engineering can be found here We currently don't have this on but we soon will turn it on.
    • Eric considers Replication and Query Optimization the hardest part of AD. You also have to know that Eric works with very large implementations.
    • Don't ever user eseutil to repair your AD database. Never even tried that one in production and will never try it :)
    • Establish baselines: run SPA from time to time and run Perfmon a lot.
    • Collect Crash dumps and look at your own dumps before asking PSS.
    • The following commands will help with the crash dumps before calling PSS.

      • windbg –z foo.dmp
      • sympath SRV*http://msdl.microsoft.com/download/symbols
      • !analyze -v

That was just a taste of what Eric talked about. If you ever get a chance to go see Eric speak then do it!! Eric lived up to his reputation and in fact he exceeded all expectations.

He could have a great career after Microsoft as a college professor or high school teacher if he wanted to. Very smart but also good at conveying his thoughts and ideas to the audience. I can't imagine anyone not giving him a 5/5 on any evaluation.


  1. I must agree, he was a very impressive speaker, he was personable, and approachable. His depth of AD is crazy, but I suppose it would be if he helped develop it. ;) I wish he would blog more though, but I'm going to guess he's kept pretty busy in his current role; that and when I saw something like 10000 unread messages across his mail folder hierarchy, that was also a hint. I talked to him after the presentation though and he invited the email and said he would promptly respond.

    -Eric Jansen

  2. Sounds as though you had fun; it has most definitely been interesting reading your post here about what was spoken about.

    Thanks Mike,