Addressing scalability ,performance in a .net web application

Question

I\'m working on a .net portal which would be having lots of concurrent users. so scalability,performance need to be addressed in the design and architecture. We plan to use load

Answer 1

I suggest you take a look at the Patterns and Practices groups guidelines for performance, more specifically Chapter 6 - Improving ASP.NET Performance of the guideline. I agree with Cheeso that you should seriously consider NOT physically splitting your application layer and UI layer if you can. The P&P guideline has the following notes:

Avoid Unnecessary Process Hops

Although process hops are not as expensive as machine hops, you should avoid process hops where possible. Process hops cause added overhead because they require interprocess communication (IPC) and marshaling. For example, if your solution uses Enterprise Services, use library applications where possible, unless you need to put your Enterprise Services application on a remote middle tier.

Understand the Performance Implications of a Remote Middle Tier

If possible, avoid the overhead of interprocess and intercomputer communication. Unless your business requirements dictate the use of a remote middle tier, keep your presentation, business, and data access logic on the Web server. Deploy your business and data access assemblies to the Bin directory of your application. However, you might require a remote middle tier for any of the following reasons:

• You want to share your business logic between your Internet-facing Web applications and other internal enterprise applications.
• Your scale-out and fault tolerance requirements dictate the use of a middle tier cluster or of load-balanced servers.
• Your corporate security policy mandates that you cannot put business logic on your Web servers.

If you absolutely have to split the application logic up anyways, you could use WCF as a transport mechanism. I'm not sure how it stacks up against remoting when it comes to performance. However, I seem to remember that this is the guideline Microsoft is pushing.

Clemens Vasters (Technical Lead for the Microsoft .NET Service Bus) talks about WCF vs. Remoting in this answer on MSDN forums.