This may be the wrong question to ask but, what's the best way to replicate a large load on an asp.net web application? Is there an easy way to simulate many requests on particular pages? Or is the best thing to use a profiler to track a single request and then work out from that if the performance is ok?  It would be good to know how well a web app works with a server spec. I'd like to be able to simulate heavy traffic on my testing server so that I can work out if the production server is good enough (specifically with iis/asp.net not db performance).
Is there a way to test an application where you simulate a hundred different clients connecting to a IIS server and asking the same data? At the customer where our project is running they have 400 computers and they often do stress tests with all computers. I on the other hand have only got my laptop... (and a development server).  (In my case the data is asked through a WebORB Gateway).
What is the Killing form of $\mathfrak{gl}_{m}$? Consider the Killing form of the Lie algebra $\mathfrak{gl}_{m}$. Then $\{e_{ij}\}$ is a basis for this Lie algebra where $e_{ij}$ is a matrix with 1 in the $i$th row, $j$th column and 0 everywhere else. Then every $A = (a_{ij}) \in \mathfrak{gl}_{m}$ can be written as $A = \sum_{i, j = 1}^{m}a_{ij}e_{ij}$. Since $[e_{ij}, e_{kl}] = \delta_{jk}e_{il}-\delta_{li}e_{kj}$, we have $ad(a)e_{ij} = \sum_{kl}(a_{ki}\delta_{lj} -a_{jl}\delta_{ki})e_{kl}$. From this we have $$ad(a)ad(b)e_{ij} = \sum_{k, r, s}(a_{rk}b_{ki}\delta_{sj} + a_{ks}b_{jk}\delta_{ri} - a_{ri}b_{jk}\delta_{sk} - a_{js}b_{ki}\delta_{rk})e_{rs}.$$ From this how can I see that the Killing form is $2m tr(ab) - 2tr(a)tr(b)$. I know that the Killing form is just the trace of the above centered equation, but I seem to be getting confused with all the indices. Sorting Directory.GetFiles() System.IO.Directory.GetFiles() returns a string[].  What is the default sort order for the returned values?  I'm assuming by name, but if so how much does the current culture effect it?  Can you change it to something like creation date?   Update: MSDN points out that the sort order is not guaranteed for .Net 3.5, but the 2.0 version of the page doesn't say anything at all and neither page will help you sort by things like creation or modification time.  That information is lost once you have the array (it contains only strings).  I could build a comparer that would check for each file it gets, but that means accessing the file system repeatedly when presumably the .GetFiles() method already does this.  Seems very inefficient. Wikipedia lists the following pseudocode for HMAC:  function hmac (key, message)     if (length(key) &gt; blocksize) then         key = hash(key) // keys longer than blocksize are shortened     end if     if (length(key) &lt; blocksize) then         // keys shorter than blocksize are zero-padded ('∥' is concatenation)          key = key ∥ [0x00 * (blocksize - length(key))]      end if      // Where blocksize is that of the underlying hash function        o_key_pad = [0x5c * blocksize] ⊕ key      // Where ⊕ is exclusive or (XOR)     i_key_pad = [0x36 * blocksize] ⊕ key       // Where '∥' is concatenation        return hash(o_key_pad ∥ hash(i_key_pad ∥ message))  end function   Why are they there?  How were they chosen?  It seems to me that  $hash(key + hash(message))$ (where + is concatenation) would suffice.    Obviously I'm missing something.  What is it? Rectifiability of a curve Let $f$ be a function defined on $[0,1]$ by   $$f(x) = { 0, \text{ if } x = 0} $$ $$f(x) = { x \sin \frac 1 x , \text{ if } 0 &lt; x \leq 1} $$  Prove that the curve $\{(x, f(x)) : x \in [0,1]\}$ is not rectifiable.   I'm not sure how to approach this. The general idea seems logical, we're proving that the length of the curve is infinite, but the method seems difficult to find. I am a beginner with Fourier series and I have to evaluate the sum   $$\sum_{n  =1}^{\infty}{\sin\left(n\right) \over n}$$  I don't know which function I have to take to evaluate the fourier series ... Someone can give me a hint ?  Thanks in advance! When overriding equals in Java, why does it not work to use a parameter other than Object? I ran into an interesting behavior recently.  It seems that if I override .equals() to take a parameter other than Object, it doesn't get called.  Can anyone explain to me why this is happening?  It seems to violate my understanding of polymorphism in OOP, but maybe I'm missing something.  Here's much simpler code that shows what I'm seeing:  public class MyClass {   private int x;   public MyClass(int n) { x = n; }   public boolean equals(Object o) { return false; }   public boolean equals(MyClass mc) { return x == mc.x; }   public static void main(String[] args) {     List&lt;MyClass&gt; list = new ArrayList&lt;MyClass&gt;();     list.add(new MyClass(3));     System.out.println("Contains 3? " + list.contains(new MyClass(3)));   } }   When this is run, it prints "Contains 3? false".  It looks like the equals(Object) function is called, even though there is another that would work.  By contrast, if I write equals like this the code works as expected:  public boolean equals(Object o) {   if(!(o instanceof MyClass))     return false;   MyClass mc = (MyClass)o;   return x == mc.x; }   Why isn't it figuring out which version of the function to call based on the type of the parameter? Can we use an Android phone as a Wi-Fi repeater? Can we use an Android phone as a Wi-Fi repeater?  Imagine situation when you can access a weak Wi-Fi signal from a free hotspot (coffee shop) signal near window, but want to work in the middle of the room. Then we can put the phone on the window sill to spread the signal over the entire home.  Is it feasible? Use (or non-use) of articles before abstract nouns Standard definition of graph says that it is an ordered pair G=(N,L) where N is set of nodes and L is set of lines which connect the nodes.   From what I've read, the set L can be empty, but can set N be empty too?  I'm mainly asking this because for my exam, I found numerous problems that go like this: Graph X is given. How many subgraphs with property Y exist? Often the number depends on the definition of graph. How to isolate the text from a bitmap logo? I have been given a logo from a client that they want me to 'extract' or 'cut' the text out of and use just the text with a transparent background to fit with the design ethos of their marketing.   I'm using Photoshop CS6 and have tried using channels, magic wand and eraser but I can't get clean edges on the text.  I'm pretty new to Photoshop and any help appreciated. Good refactoring support for C++ The Visual Studio refactoring support  for C# is quite good nowadays (though not half as good as some Java IDE's I've seen already) but I'm really missing C++ support.  I have seen  and am currently trying it out, but maybe one of you guys know a better tool or plugin?  I've been working with  now for a week or two and got totally addicted. Thanks for the tip, I'll try to convince my boss to get me a license at work too.  I've been bughunting for a few days since Visual Assist X kept messing up my Visual Studio after a few specific refactorings, It took me (and customer support) a week to hunt down but let's say for now that Visual Assist X is not a good combination with . Polygon intersection using turf js Allowing a group Read-Write Access to a directory Prove by contradiction (not using a calculator) that $\sqrt6 + \sqrt2 < \sqrt{15}$? I asked  yesterday, approximately 18 hours ago ("2011-12-13 20:24:03Z" according to the hover text), and it's still being displayed as "today".  I assume the "Z" in the timestamp refers to Zulu time, so I , and the date (2011-12-14) differs from the timestamp on the question.  I don't pretend to understand all of the complexities when converting time zones, but I thought it was strange enough to report. If it matters at all, I'm in US-Eastern. I am interested in how uncertainty can be accounted for when considering the risk of extinction of a species. Forgive me for extending a rather tired thought experiment, but at least it's familiar territory and I hope it illustrates what I am trying to understand.  Let's say that Schrödinger was not satisfied with killing and not killing only one cat, so he went out and collected the last 15 remaining Himalayan Snow-Cats. He put each one in a box with a vial of poison, hammer, and a trigger device for releasing the hammer. Each trigger device has a known probability of releasing the hammer within any given hour, and the poison will take 5 hours to kill a cat (things got a bit trippy when he used radioactive decay, so this time he steers clear of quantum mechanics). After one hour, Schrödinger receives a notice from the ethics board telling him he's nuts and ordering him to release the cats immediately. He pushes a button which opens a cat-flap at the back of each box, thus releasing them all back into the wild. By the time the humane society check the boxes, all the cats have bolted. Before anyone can restrain him, Schrödinger detonates the remaining triggers, so nobody knows how many of the cats were poisoned.  The probability that each of the cats is poisoned is as follows:   0.17 0.46 0.62 0.08 0.40 0.76 0.03 0.47 0.53 0.32 0.21 0.85 0.31 0.38 0.69   After 5 hours have elapsed and all poisoned cats have died, what is the probability that there are:   (A) More than 10 Himalayan Snow-Cats still alive  (B) 10 or less still alive (C) 5 or less still alive (D) 2 or less still alive Viber notification is not in the right position How is Cooper's age justified? Split Data Based on Year in a Visual force Page PDF Say I want to copy the contents of a directory excluding files and folders whose names contain the word 'Music'.  cp [exclude-matches] *Music* /target_directory   What should go in place of [exclude-matches] to accomplish this?