Omar AL Zabir blog on ASP.NET Ajax and .NET 3.5

Working hard to enrich millions of peoples' lives

  • Droptiles: Metro style Live Tiles enabled Web 2.0 Dashboard

    Droptiles is an Open Source Windows 8 Start like Metro style Web 2.0 Dashboard. It builds the experience using Tiles. Tiles are mini apps that can fetch data from external sources. Clicking on a tile launches the full app. Apps can be from any existing website to customized website specifically built to fit the Dashboard experience. Droptiles is built almost entirely of HTML, Javascript and CSS and thus highly portable to any platform. The sample project is built using ASP.NET to show some server side integration, like Signup, Login and getting dynamic data from server. But with very little change you can port it to PHP, Ruby, JSP or any other platform. Droptiles is the sequel of my Dropthings, which is the first Open Source Web 2.0 Dashboard.

  • Caching WCF javascript proxy on browser

    When you use WCF services from Javascript, you have to generate the Javascript proxies by hitting the Service.svc/js. If you have five WCF services, then it means five javascripts to download. As browsers download javascripts synchronously, one after another, it adds latency to page load and slows down page rendering performance. Moreover, the same WCF service proxy is downloaded from every page, because the generated javascript file is not cached on browser. Here is a solution that will ensure the generated Javascript proxies are cached on browser and when there is a hit on the service, it will respond with HTTP 304 if the Service.svc file has not changed.

  • Memory Stream Multiplexer–write and read from many threads simultaneously

    Here’s an implementation of MemoryStream like buffer manager where one thread can write and many threads can read simultaneously. Each reading thread gets its own reader and can read from the shared stream on its own without blocking write operation or other parallel read operations. It supports blocking Read call so that reader threads can call Read(…) and wait until some data is available, exactly the same way you would expect a Stream to behave. You can use this to read content from network or file in one thread and then get it read by one or more threads simultaneously. Readers do not block writing. As a result, both read and write happens concurrently. Handy for building http proxy where you are downloading a certain file and you have multiple clients asking for the same file at the same time. You can download it in one thread and let one or more client threads read from the same buffer exactly at the same time. You can also use this to read same file on disk from multiple clients at the same time. You can also use this to implement a server side cache where the same buffer is read by multiple clients at the same time.

  • ReadLine on Binary Stream

    When you are reading data from a binary stream, like NetworkStream or FileStream and you need to read both binary chunks as well as read one text line at a time, you are on your own as BinaryReader nor Stream supports ReadLine. You can use StreamReader to do ReadLine, but it does not allow you to read chunks of bytes. The Read(byte[], int, int) is not there on StreamReader.

  • Browse internet faster and save power using a smart HOSTS file

    Internet is full of flash ads nowadays that make page load slower, render slower and consumes more CPU, thus power. If you can browse without having any flash ads or in fact any ads loaded and without any of the tracking scripts - you can browse much faster, scroll through pages much smoother and have more hours from your battery. Nowadays, most websites use scripts from various analytics sites that track your browsing habit, use IFRAME to load tracking and social networking widgets. All of these add considerable delay to page loading and make browser consume more CPU and bandwidth. If you can turn all of them off, browsing internet feels a lot smoother, faster and you get more work hours while running on battery.

  • Get Dropthings license by donating to charity

    Now you no longer pay me for Dropthings license instead you donate the money to a charity and I will give you the license. In case you don’t know what Dropthings is, it is a Web 2.0 Personalizable Dashboard framework that you can use to build Web 2.0 personalizable websites and enterprise dashboards. It is built using ASP.NET AJAX, jQuery, Silverlight, .NET 3.5, Entity Framework, SQL Server. It is in use in big companies like BT, Intel, Microsoft, Thomson Reuters; many government organizations like State Police, Canada Border Protection etc. Since it is a state of the art .NET 3.5 codebase, it is sometimes used as a starting point for an application with all the best practices already in place in order to build an N-tier web app using popular technologies, design patterns and testing methods. Dropthings helps you build web app utilizing extensive performance and scalability research that I have done to scale websites to millions of users. It also helps you build a codebase that is highly testable. It shows you how to test AJAX applications using automated test tools like WatiN. It has a business layer and a data access layer that is fully unit testable, nearly 100% test coverage and uses Inversion of Control pattern to the fullest.

  • MVP Open Day 2011 at Cambridge

    Microsoft Research arranged MVP Open Day 2011 at Cambridge on Oct 24, 2011. Beautiful university, made me feel like giving up my job and going back to study. Amazing research work going there, very thought provoking. The session on DNA programming was out of the world. The most surprising thing I learnt that a 10cm long DNA strand can hold 10TB digitally encoded data and cells are thousand times more robust computing system than silicon based chips. Moreover, cells are self-powered, super energy efficient micro processors, hundred years ahead of Intel processors.

  • Tweaking WCF to build highly scalable async REST API

    At 9 AM in the morning, during the peak traffic for your business, you get an emergency call that the website you built is no more. It’s not responding to any request. Some people can see some page after waiting for long time but most can’t. So, you think it must be some slow query or the database might need some tuning. You do the regular checks like looking at CPU and Disk on database server. You find nothing is wrong there. Then you suspect it must be webserver running slow. So, you check CPU and Disk on webservers. You find no problem there either. Both web servers and database servers have very low CPU and Disk usage. Then you suspect it must be the network. So, you try a large file copy from webserver to database server and vice versa. Nope, file copies perfectly fine, network has no problem. You also quickly check RAM usage on all servers but find RAM usage is perfectly fine. As the last resort, you run some diagnostics on Load Balancer, Firewall, and Switches but find everything to be in good shape. But your website is down. Looking at the performance counters on the webserver, you see a lot of requests getting queued, and there’s very high request execution time, and request wait time.