I am working on a smartphone application that will require a backend web service - but I have absolutely clueless to how much it will cost.  Web Service will handle:  - login of users  - cataloging of our user base  - holding minimal profile information for users (the only binary data is a display picture which will be &lt; 20k each)  - performing some very minor calculation/algorithm before return results  - All the above will be communicated to server from a smartphone (iPhone/BlackBerry/Android)    Bandwidth Requirements:  - We want to handle up to 10k users throughout the day.  - I predict 10k * 50 HTTP requests a day = 500,000 requests a day * 30 = 15 million requests a month  Space Requirements:  - Data will be in SQL database.  - I predict 1MB/user * 10k = 10GB + overhead. In other words - space is not a big issue.    Software Requirements: (unless someone knows an alternative)  - Windows Server 2008 + IIS  - MSFT SQL Server    Note: This is 100% new to me, so please hit me with all you got. Do I need Windows Server or are there alternative? Is it better to get multiple cheap servers to distribute load? Will Amazon S3 work for me? How about Windows Azure?  EDIT note: At this point in time - I'm am more concerned with COST and how that cost will scale. So if you provide a service recommendation, could you help ballpark to how much these requirements would cost?    Thank you!!
This is a  about  Related:      I have a question regarding capacity planning. Can the Server Fault community please help with the following:   What kind of server do I need to handle some number of users? How many users can a server with some specifications handle? Will some server configuration be fast enough for my use case? I'm building a social networking site: what kind of hardware do I need? How much bandwidth do I need for some project? How much bandwidth will some number of users use in some application?
Selenium/PhantomJS raises error Where can I get a Master Ball? I remember in previous generations that finding a Master Ball would typically come after a major Boss fight. You could have also gotten through some form of lottery (I think this was in Pearl).  If anything, where and when will I be able to find Master Balls in Pokemon X&amp;Y? Please help me  to evaluate combinatorially the following sum: $$\sum_{k=0}^n \binom{n}{k}$$   Thank you. How can anything ever fall into a black hole as seen from an outside observer? The event horizon of a black hole is where gravity is such that not even light can escape. This is also the point I understand that according to Einstein time dilation will be infinite for a far-away-observer.  If this is the case how can anything ever fall into a black hole.  In my thought experiment I am in a spaceship with a powerful telescope that can detect light at a wide range of wavelengths.  I have it focused on the black hole and watch as a large rock approaches the event horizon.  Am I correct in saying that from my far-away-position the rock would freeze outside the event horizon and would never pass it? If this is the case how can a black hole ever consume any material, let alone grow to millions of solar masses.  If I was able to train the telescope onto the black hole for millions of years would I still see the rock at the edge of the event horizon?  I am getting ready for the response of the object would slowly fade.  Why would it slowly fade and if it would how long would this fading take?  If it is going to red shift at some point would the red shifting not slow down to a standstill? This question has been bugging me for years!  OK - just an edit based on responses so far.  Again, please keep thinking from an observers point of view.  If observers see objects slowly fade and slowly disappear as they approach the event horizon would that mean that over time the event horizon would be "lumpy" with objects invisible, but not passed through?  We should be able to detect the "lumpiness" should we not through? I'm calculating the covariance of a distribution in parallel and I need to combine the distributed results into on singular Gaussian. How do I combine the two?  Linearly interpolating between the two almost works, if they are similarly distributed and sized.   provides a forumla at the bottom for combination but it doesn't seem right; two identically distributed distributions should have the same covariance, but the formula at the bottom of the page doubles the covariance.  Is there a way to combine two matrices? Quantum entanglement faster than speed of light? recently i was watching a  on quantum computing where the narrators describes that quantum entanglement information travels faster than light!  Is it really possible for anything to move faster than light? Or are the narrators just wrong?  Regards, Convergence of sequence given by $x_1=1$ and $x_{n+1}=x_n+\sqrt{x_n^2+1}$ Be $(x_n)_n\ge 1 $  such that $x_1=1$ and $x_{n+1}=x_n+\sqrt{x_n^2+1}$ for every $n\ge 1$. Prove that the sequence $y_n=(2^n/x_n)_n \ge 1$ is convergent and find it s limit.  Being positive and decreasing, $y_n$ is clearly convergent. But finding it's limit really put me intro trouble. Any help?  Thank you! Functions of Independent Random Variables How to get IOS "tossing feature" in Wolfram IOS Player to work in Mathematica How to pipe the result of 'date' command to 'mv' command I want to rename my file to the current timestamp.I know how to get the current timestamp("date +%s") but how can I pipe it to 'mv' command? I want to communicate between several computers on my network (static Ethernet), through SSH. In order to do that I need to run ssh-add every time I log in on a specific machine, how can I do it so that it's set up once and it doesn't ask me for the passphrase every time I log in or reboot my machine?  I know that there is a way that you should add some lines to the bash_profile file, but I still need to type the password every time I reboot/log in to a specific machine.  if [ -z "$SSH_AUTH_SOCK" ] ; then     eval `ssh-agent -s`     ssh-add fi "Reality" of length contraction in SR I have a simple question answer to which would help me more deeply understand the concept of (non)commutative structures. Let's take for example (our teacher's definition of) a ring:  Let $R\neq \emptyset$ be a set, let $\oplus:A\times A \to A$ and $\bullet :A\times A \to A$ be binary operations. Moreover, let $(R, \oplus)$ be a commutative group, $(R, \bullet)$ be a monoid and following property holds for all $a, b, c\in R$: $$a\bullet(b\oplus c) = (a\bullet b)\oplus(a \bullet c)$$ $$(b\oplus c)\bullet a = (b\bullet a)\oplus(c \bullet a)$$ Then ordered triple $\mathbf R = (R, \oplus, \bullet \mathbf)$ is called a (unitary) ring.  Moreover, we call ring $\mathbf R$ commutative iff $(R, \bullet)$ is a commutative monoid. Commutativity of a ring is always a matter of its multiplicative operation because the additive operation is always assumed to be commutative.  Could anyone explain me the bold part? Why do we even in non-commutative rings (and fields etc.) assume the addition to be always commutative? Is there some serious reason? Would it make any trouble? Or studying of structures with non-commutative addition just doesn't give us anything new so we can take addition as commutative simply because of our comfort? Is using Gravatar a security risk? This has been . It is unfortunate the accepted answer is so far from reality.   There are some facts:    's MD5 hash is an unsalted MD5 hash of an email address. A 3rd party could harvest every MD5 hash for every user's email on Stack Overflow.  The 3rd party could store all the hashes in a lookup table Email addresses are usually of a very particular format The attacker could start with a brute force of @gmail.com followed by @yahoo.com, etc. The attacker has the advantage that he/she could attack a huge set of emails in one go. So instead of needing to brute force every email individually the attacker can brute force in bulk.   The algorithm is quite simple, calculate a "random" MD5, look it up in the lookup table.       Is Gravatar a big enough security risk to warrant caching images locally?     Examples:    Someone could harvest about 50k email addresses quite easily and shoot off a bogus promotion from Stack Overflow to all the users. A spammer/stalker/generic evil guy can tie you identity to all the rest of the sites that use Gravatar. How can I find the codes related to a function in GAP? When I use "??" in front of the name of function there is no help, so I want to find the code of function among packages. I am currently working on a project to create a (not prepaid) postage label.  In java, I would go about doing this by creating a bufferedimage and adding various other images to it to create what I want.  What I want is to put text, converted to an image, onto a template letter, to make a proper postage label.    For example, imagine I was given a document with blank spaces such as:  "Name: _________"  This document is in the form of an image, and I want to use apex and visualforce (the page is already constructed, I am just stuck at the image manipulation part) to add whatever name the user types in onto the image and pack it and email the new image.  The question I have here is: where do I even start?  Java is a little nicer when it comes to image manipulation, as far as I can see.  I've looked into using a web service and sending a soapxml request to return a proper encoded image, but I haven't found a web service that can do this.  Any pointers would be nice. Thanks. If $f:D\to D’$ is analytic and $u: D'\to R$ is harmonic then the composition of $u$ and $f$ is harmonic in $D$ If $f:D\to D’$ is analytic and $u: D'\to R$ is harmonic then the composition of $u$ and $f$ is harmonic in $D$.  How can I show that the above statement is true/false? Can anyone help me? Is stack.imgur currently down? I just wrote a question before this one and had trouble uploading a screenshot. The drop your image dialog throws no warning or error, but after uploading it won't show.  I also noticed that other questions won't load their images. Could this be some issue with imgur or similar?  Example:     When opening the image in a separate tab, Chrome gives a "too many redirects" error:    This might be linked to Geometric interpretation of $\frac {\partial^2} {\partial x \partial y} f(x,y)$ What does it mean to "align" partitions? I am familiar with what partitions are, but I saw , and realised I didn't know what "aligned partitions" are.  So what does it mean to "align" partitions? What are the benefits, and the downsides?