As submitted to http://acanac.org/blogs/geek/

I'm working on a project at my place of employment where my team is tasked with designing and implementing a new Microsoft .Net based web farm to replace our aging infrastructure.  Sounds easy enough, doesn't it?  For those of you who don't know what a web farm is, it is simply a collection of web servers hosting the same web sites.  We do this to increase availability of the sites.  More servers can serve more requests.  Alright, we got that out of the way. 

All kinds of questions arise when you have a web farm.  Things like:

• How do we ensure that the configuration is identical between the servers?
• How do we ensure that the content is identical between the servers?
• How do we monitor the servers to ensure availability to our users?
• How do we configure the servers to optimally deliver .Net 3.0 based content?

That's just a few.  We have many.  One of the questions I can't find an answer to is this:  Should IIS web servers be on dedicated servers, virtual servers, or does it even matter?  I'm having trouble getting an answer on that one.  If any of my readers have an opinion on that, I would love to hear from you.  During my hunt for information, I came across a white paper written by Microsoft about how they manage the Microsoft.com web farm.  You can  read it here:   http://technet.microsoft.com/en-us/library/bb735209.aspx .

Personally, I found the paper to be very interesting and I'd like to share a few stats with you that quite literally knocked my socks off.

• There are 80 web servers that deliver Microsoft.com to the Internet users.
• These are configured as 10 clusters of 8 servers (we can discuss clustering another day).
• There are 70 million page views per day at Microsoft.com.
• There are 10,000 http requests per second.
• All of the web servers are HP Proliant DL 585 servers.
• Each server has four 2.2 GHz AMD Opteron x64 based CPU's.
• Each server has 16 GB of RAM.
• All servers are running 64-bit Windows Server 2003 with IIS 6.0.

Wow.  That really is all I can say to that.  The article was published in February of 2006, so they may have upgraded or increased capacity since then.  The farm is definitely doing the job though, I have nothing but good experiences with the Microsoft.com web site.  It's always speedy and very responsive.  Kudos to Microsoft for getting it right.  We will certainly be looking to them as a role model for our designs.  Later on, I'll fill you in on how we plan to keep the servers in sync.  Stay tuned.