Epractize question?

[Amandeep Singh]

With the release of a new product line, there has been a significant increase in the volume of transactions on your web site. You need to scale your application and manage session failover. What is the best option for scalability?
A. Add additional web servers and application servers
B. Introduce a High Availability pair and utilize sticky sessions
C. Add additional application servers and implement DNS round robin
D. Add additional application servers and use clusteredHttpSession

The answer marked is D. I cannot understand, why not A?

When generally scalability is talked, it is always more about hardware's & resources rather than configurations like clusteredHttpSession.

[naresh kumar nand]

If the answer is A then how do you handle session failover which is key point in the question. From all the options provided which is the best option which can satisfy all the criteria.

Session Failover: In cluster environment for a user session all the requests are directed to the same server to maintain this and to handle fail over, if a server while servicing a request if it goes down OR if server has taken more time to process the request. To handle these kind of scenarios clusteredHttpSession is one the ways to achieve.

[Amandeep Singh]

Thanks for reply, Oops I almost overlooked the word session failover.

I don't know why it happens sometimes, instead of focusing on all the facts of the question, somehow I get to concentrate on the last piece question only (

What is the best option for scalability?

)