How to get Web Application and DB Server High Availibility

I have a Web application made in ASP.NET and MS SQL 2005 as database

ASP.NET Web App is hosted on : http://192.168.0.90

and MS SQL Server DB on : 192.168.0.91

User use url : http://192.168.0.91 to access the server.

MY DR IP address for Web App http://192.168.0.150 and Database is : 192.168.0.151

Suppose my Web Server Fails. i need to Automatically divert user to m开发者_如何学Cy Web Application DR Server IP

same with DB Server.

without user knowing it ? how can i do it...

Waiting for your earliest revert.

Regards

Hasnain

preferred is the process should be automatic

For the web application use DNS instead like myapp.domain.com and assign two IPs (A records) to it. It will be working as round-robin load balancing and when one server will crash, it will direct you to the another one. This is the simplest yet quite effective method providing some extra availability, assuming you have session in external database or you are using clustered storage. Also, when one of your webservers is not available, you can dynamically remove it's IP from the DNS, and this DNS A record should have 300 seconds TTL.