As promised during my TechTalk today at Microsoft Denmark, here are the links to all slides and demo code. Unfortunately you'll not be able to download the VPC's as those total around 30GB. Download slides & code I sincerely hope you enjoyed the presentation as much as I did. Either way, I'd appreciate your comments on SpeakerRate - Thanks :)

What does Flash, upload, cookies, IIS load balancing and cookies have to do with each others? More than I'd like :( When users need to upload files I often use the Flash based SWFUpload component. It allows for multiple file selection and progress display during upload. Handling the uploaded files on the .NET side is rather easy: for (int i = 0; i < Request.Files.Count; i++) { HttpPostedFile hpf = Request.Files[i]; // ... Save / process the HttpPostedFile } One of the arguments for using Flash for web designs is that...

Once you start distributing your ASP.NET website across multiple webservers, you're going to need a way to share session state. That is, unless your app is stateless, in which case scaling it should be a breeze! One of the easiest ways to provide common session state for a small cluster (very dependant on load and hardware specs, but ~10 servers max, per state server), is to use the built-in ASP.NET State Service. It's a free service that's installed alongside the .NET Framework on all Windows servers. While the InProc session storage is stored directly in the w3wp process,...

One of the best way to improve performance of any website is to reduce the load from clients by allowing them to cache resources. There are various ways to ensure we utilize client side caching to the fullest extent, an often overlooked parameter however, is the actual URL for the resource we want to cache. The traditional methods Basically client side caching comes down to three different parameters, the cache policy, the expiration dates as well as the last-modified / etag of the resource. Through the no-cache policy we can completely disallow all caching of the resource,...

Once you start receiving visitors from all over the world, a new kind of scaling issue arise. It's not a matter of adding more servers to the cluster or optimizing code (we'll assume these factors are perfect), it's a simple matter of geography and mathematics. Serving code from one end of the world to the other will take time, no matter how quick your servers are handling the request. The speed of light suddenly seems quite slow. At one of my current projects we serve a lot of image data. Letting US based clients fetch all the data from...

There are two primary reasons for venturing into the realms of clustering/load balancing - availability & scalability. In this post I'll give a quick demo of how to setup Windows Network Load Balancing (NLB) on Server 2003 and how it affects the availability of a web application. When we have several nodes doing the same thing, if one of them fails, the cluster as a whole continues - provided that the nodes are not so overburdened that a single node failing will kill the others due to the extra load. Most applications will have an upper limit on how...