How to increase my Web Application's Performance??

Question

I have a ASP.NET web application (.NET 2008) using MS SQL server 2005, I want to increase the performance of the web site, If anyone have an article contains steps to do that, step by step , In SQL(Indexes, ..... etc.) and in the code.
Thanks in advance
Best Regards

Answer 1

I think the best we can do from here is give you some pointers:

• query less data from the sql server (caching, appropriate query filters)
• write better queries (indexing, joins, paging, etc)
• minimise any inappropriate blockages such as locks between different requests
• make sure session-state hasn't exploded in size
• use bigger metal / more metal
• use appropriate looping code etc

But to stress; from here anything is guesswork. You need to profile to find the general area for the suckage, and then profile more to isolate the specific area(s); but start by looking at:

• sql trace between web-server and sql-server
• network trace between web-server and client (both directions)
• cache / state servers if appropriate
• CPU / memory utilisation on the web-server

Answer 2

I think First of all you have to find your Bottlenecks and then try to improve those.

This helps you to perform exactly where you have serios problem.

An in addition you needto improve your Connection to DB. For exampleusing a Lazy , Singletone Pattern and also create Batch request instead of single requests. It help you to decrease DB connection.

Check your cache and suitable loop structures.

another thing is to use appropriate types, forexample if you need int donot create a long and etc

at the end ypu can use some Profiler (specially in SQL) andcheckif your queries implemented as well as possible.

Answer 3

Performance tuning is a very specific process. I don't know of any articles that discuss directly how to achieve this, but I can give you a brief overview of the steps I follow when I need to improve performance of an application/website.

1. Profile.

   Start by gathering performance data. At the end of the tuning process you will need some numbers to compare to actually prove you have made a difference. This means you need to choose some specific processes that you monitor and record their performance and throughput.

   For example, on your site you might record how long a login takes. You need to keep this very narrow. Pick a specific action that you want to record and time it. (Use a tool to do the timing, or put some Stopwatch code in you app to report times. Also, don't just run it once. Run it multiple times. Try to ensure you know all the environment set up so you can duplicate this again at the end.

   Try to make this as close to your production environment as possible. Make sure your code is compiled in release mode, and running on real separate servers, not just all on one box etc.

2. Instrument.

   Now you know what action you want to improve, and you have a target time to beat, you can instrument your code. This means injecting (manually or automatically) extra code that times each method call, or each line and records times and or memory usage right down the call stack.

   There are lots of tools out their that can help you with this and automate some of it. (Microsoft's CLR profiler (free), Redgate - Ants (commercial), the higher editions of visual studio have stuff built in, and loads more) But you don't have to use automatic tools, it's perfectly acceptable to just use the Stopwatch class to time each block of your code. What you are looking for is a bottle neck. The likely hood is that you will find a high proportion of the overall time is spent in a very small bit of code.

3. Tune.

   Now you have some timing data, you can start tuning.

   There are two approaches to consider here. Firstly, take an overall perspective. Consider if you need to re design the whole call stack. Are you repeating something unnecessarily? Or are you just doing something you don't need to?

   Secondly, now you have an idea of where your bottle neck is you can try and figure out ways to improve this bit of code. I can't offer much advice here, because it depends on what your bottle neck is, but just look to optimise it. Perhaps you need to cache data so you don't have to loop over it twice. Or batch up SQL calls so you can do just one. Or tighten your query filters so you return less data.

4. Re-profile.

   This is the most important step that people often miss out. Once you have tuned your code, you absolutely must re-profile it in the same environment that you ran your initial profiling in. It is very common to make minor tweaks that you think might improve performance and actually end up degrading it because of some unknown way that the CLR handles something. This is much more common in managed languages because you often don't know exactly what is going on under the covers.

Now just repeat as necessary.

If you are likely to be performance tuning often I find it good to have a whole batch of automated performance tests that I can run that check the performance and throughput of various different activities. This way I can run these with every release and record performance changes each release. It also means that I can check that after a performance tuning session I know I haven't made the performance of some other area any worse.

When you are profiling, don't always just think about the time to run a single action. Also consider profiling under load, with lots of users logged in. Sometimes apps perform great when there's just one user connected, but when they hit a certain number of users suddenly the whole thing grinds to a halt. Perhaps because suddnely they are spending more time context switching or swapping memory in and out to disk. If it's throughput you want to improve you need to be figuring out what is causing the limit on throughput.

Finally. Check out this huge MSDN article on Improving .NET Application Performance and Scalability. Specifically, you might want to look at chapter 6 and chapter 17.