09 December 2009

eBay Architecture

Recently I was curious to find out how big sites like eBay are build and running. After a quick research I was able to find some quite interesting articles.

I was surprised to find out that eBay doesn't use transactions. As well they do not use foreign keys in their database (the same thing as the SharePoint_AdminContent database). It looks like this is the latest trend ;-)

If you are curious like me, take a look at the following:

Randy Shoup on eBay's Architectural Principles
eBay Architectural Strategies, Patterns, and Forces
Software Engineering Radio: eBay's Architecture Principles with Randy Shoup
Scalability Best Practices: Lessons from eBay
Dan Pritchett on Architecture at eBay
You Scaled Your What?
High Scalability: eBay Architecture

24 August 2009

jQuery FullCalendar and ASP.NET MVC

Recently I had to integrate jQuery FullCalendar into ASP.NET MVC application. Up to now I was not able to find such an example, so I will try to provide one. I assume that you are familiar with ASP.NET MVC, jQuery and FullCalendar component, so I’m not going to introduce each technology.
image I will use the default ASP.NET MVC Web Application template to create new project. Please, note that the jQuery is included by default, so there is no need to download and reference it.
The first step would be to place FullCalendar JavaScript and style-sheet files inside project’s Scripts and Content directory as shown in the picture.
Then we need to reference the files we just added to our project. I will do it by placing the following lines of code inside the <head> section of Site.Master file:
<head runat="server">
   <title><asp:ContentPlaceHolder ID="TitleContent" runat="server" /></title>
   <link href="../../Content/Site.css" rel="stylesheet" type="text/css" />
   <link href="../../Content/fullcalendar.css" rel="stylesheet" type="text/css" />
   <script src="../../Scripts/jquery-1.3.2.js" type="text/javascript"></script>
   <script src="../../Scripts/fullcalendar.js" type="text/javascript"></script>
Now we are ready to use the calendar routines inside our views. How to do it? Just create a div tag and render the calendar’s HTML code inside. Here is how to modify Home’s Index.aspx:
<asp:Content ID="indexContent" ContentPlaceHolderID="MainContent" runat="server">

   <script type="text/javascript">
       $(document).ready(function() {
               events: "/Home/CalendarData"

   <div id="calendar">
The code above will render the calendar’s HTML inside a div with id=”calendar”. The calendar data will be delivered by invoking the following URL: /Home/CalendarData. This corresponds to CalendarData method from the Home controller. This controller is supposed to return the data in Json format. Here is a sample implementation:
   public class HomeController : Controller
       public ActionResult CalendarData()
           IList<CalendarDTO> tasksList = new List<CalendarDTO>();

           tasksList.Add(new CalendarDTO
               id = 1,
               title = "Google search",
               start = ToUnixTimespan(DateTime.Now),
               end = ToUnixTimespan(DateTime.Now.AddHours(4)),
               url = "www.google.com"
           tasksList.Add(new CalendarDTO
               id = 1,
               title = "Bing search",
               start = ToUnixTimespan(DateTime.Now.AddDays(1)),
               end = ToUnixTimespan(DateTime.Now.AddDays(1).AddHours(4)),
               url = "www.bing.com"

           return Json(tasksList);

       private long ToUnixTimespan(DateTime date)
           TimeSpan tspan = date.ToUniversalTime().Subtract(
    new DateTime(1970, 1, 1, 0, 0, 0));

           return (long)Math.Truncate(tspan.TotalSeconds);

       public ActionResult Index()
           return View();

       public ActionResult About()
           return View();
The code above creates two calendar entries called “Google search” and “Bing search”. Everything should be pretty simple, except the stuff around ToUnixTimespan routine.
There is well known problem with serialization of dates in Json format. There is no strict standard, so there are several approaches to this problem. For example, take a look here. The implementation adopted by Microsoft was not recognized by FullCalendar, so I had to introduce the ToUnixTimespan routine. Basically, this routine returns the seconds after 1/1/1970.
Because of the above, you should notice that the start and end dates are represented as int:
    public class CalendarDTO
       public int id { get; set; }
       public string title { get; set; }
       public long start { get; set; }
       public long end { get; set; }
       public string url { get; set; }
If you have done everything correct, the final result will be


Edit: Due to the higher interset I have published the source code of this post here. Please note that Visual Studio 2008 is used and you need to convert the project if more recent version is used.