Creating my 1st .Net Web Farm

[travisowens]

Sorry if this is a bit off topic but I don't know of a SysAdmin forum and I figured some of you guys do this stuff.

 

Any opinions on Windows 2003's "File Replication Services" and/or "Network Load Balacing". While I'm not doubting their quality, I just wanted to hear any 1st hand thoughts on these services I need to deploy my first Web Farm and I planned on using what was built into 2003 instead of purchasing a 3rd party solution.

 

and FYI, the servers are running SP1, and I might even consider using 2003 R2 as we won't be launching the servers for a couple more months.

[Nerseus]

This is secondhand knowledge as I'm not the IS guy. We've been using network balancing for a few years now in production, back when it came with the NT Option Pack for Windows 2000 (I think). We don't use File Replication services though - we just copy all the same .NET files to each webserver. I was involved in the early stages of implementation but haven't touched it much lately.

 

SQL Server replication: not using and probably wouldn't use. I've heard some bad stories from the trenches, including a SQL Server guru (one who coded part of the optimizer in SQL 7 and SQL 2000). Not that it's problematic, just tedious and... well, you'd better have a guru help. On a different note, we've had numerous issues with SQL Server running in parallel mode (taking advantage of multiple processors) - confirmed bugs from MS with no patch. But, the parallel bugs are only on SQL Server, not web servers.

 

Just a smattering of info, but maybe it will help.

 

-ner

[travisowens]

We have a database setup that runs on a high availability server all on the SAN, the database server IS NOT on the webserver. Our goal is to get our webapps into a more fault tolerant enviroment. I am aware that trying to NLB and Sync a database requires an expert, it's very dangerous & messy work.

 

Personally I think manually sync'ing files on 2 or more webservers is a bad idea as you should never underestimate human error. The File Replication Services are pretty reliable and there's no reason you can't sync the two websites without affecting server load.

 

Actually I did some howemork and found a really good review of Network Load Balancing called "Web Farming with the Network Load Balancing Service in Windows Server 2003" by Rick Strahl found at http://www.west-wind.com/presentations/loadbalancing/NetworkLoadBalancingWindows2003.asp where the guy pulled the plug to see what happens and it's very interesting. Also he reminds us that NLB runs on the network level and not the app level, so if your server is up but your webserver is dead, it will still attemp to server web requests and fail ungraciously.

 

Because of this, we are going to rethink our plan and decide if you can live with this scenario or if we truly need 100% uptime which will require a 3rd party solution that can be app (port) aware.

 

I should also point out that IIS6 is EXTREMELY fault tolerant and each webapp runs seperately with auto restarting so the worst case scenario is a webapp crashes and restarts itself (all within a couple seconds) and does not affect any other web app. So the fact that NLB can't monitor apps isn't much to get worried about as long as you're on 2003 & IIS6.