PeterKellner.net

I’ve known about vaasnet for quite a while.  Basically, vaasnet is a way to almost instantly (OK, it took about 4 seconds to come up) grab a fresh VM (currently 99 cents an hour), do a bunch of stuff and go away.  My bunch of stuff was I need to download a bittorrent file that was about 5 gig and I know if I do it from either home or over my hotspot, bad things will happen.  If I do it at home, Comcast will send me a letter accusing me of stealing something, and if I use my Verizon hotspot, well, it’s a 5 gig per month plan.  You do the math.

Back to vaasnet.  Here is my experience today:

1. 30 seconds to put my credit card it
2. 4 seconds to boot a general purpose workstation
3. 5 seconds to RDP into it
4. 2 minutes to download bit torrent
5. 35 minutes to have bit torrent download a 5 gig file!
6. 35 minutes to have bit torrent download a 5 gig file (had to say it twice)
7. 1 minute to transfer the file to my ORCSWeb server I already have
8. $1.70 billed to my credit card.
9. OMG!

I think that about says it all.  OK, maybe not it all.

I’ll be back!

OK, now that says it all.

Introduction

If you’ve started using SqlAzure for your SqlServer with your Azure application, you’ve probably discovered that you get a reasonable number of connection failures.  The advice from the Azure team is add retry logic to all your connections to SqlAzure. There is a long discussion posted by the Azure team here.

The key paragraph states the problem as follows:

The Problem
One of the things that SQL Azure does to deliver high availability is it sometimes closes connections. SQL Azure does some pretty cool stuff under the covers to minimize the impact, but this is a key difference in SQL Azure development vs. SQL Server development.

Basically, what this means is that you must be able to deal with connections failing when you call SqlAzure.  Something that all of probably should have been doing forever, but because most of the time SqlServer is running on your local LAN and the likelihood if a connection failing was next to zero unless something else was going terribly wrong.  Certainly not something we had to do on regular basis.  To emphasize that even more, most of the controls built into asp.net that open connections to sqlserver don’t even do this and that’s from Microsoft itself.

The solution proposed in the thread mentioned above basically has you add tons of code to everyplace you access a connection object.  Personally, I don’t like that because I have hundreds if not thousands of places I open connections and inserting tens of thousands of lines of extra new untested code is a little scary.

So, what to do?

Fortunately, another team at Microsoft, known as the Windows Server AppFabric Customer Advisory Team published a general purpose solution using Extension Methods and some darn clever coding wrote a great article and published code including azure examples that solves this problem very elegantly without requiring a lot of changes to your existing code base.

In this article I plan on giving an example and publishing a sample project that uses this code with SqlAzure to solve the connection retry problem.  My goal here is not to simply restate what they published but to simply have a very simple concrete example of using their library.

This series of video presentations goes through the process of building a Speaker and Sessions Viewer for Silicon Valley Code Camp’s data using Silverlight 4 and RIA Services (Using Visual Studio 2010 Beta 2).  It starts with a brief introduction of RIA Services and is followed by screen casts and blog posts the parallel each screen cast.

The actual presentation was done at the Microsoft office in San Francisco.

Many of you know of ORCSWeb either by reputation, or by way of Scott Forsyth, one of my ASP.NET MVP brothers.  In case you don’t, they are a managed hosting solutions company specializing in Microsoft technologies.  I’ve used their basic services for quite a while and have always been very happy.  It has always seemed that anytime I’ve called them (and it always seems like the middle of the night) one of their tech support staff is always available to help me, and go the extra mile if necessary.

The company I’m now working at is small and we don’t have a lot of resources to maintain hardware and do operating system type support.  We do have a high load requirement so we need a very robust supported solution.  Before this, I’d always been in the under $50 per month type plan with ORCSWeb, but I decided I needed more servers and a higher level of support.  I really did not know what level of support to expect when signing up for the managed servers but decided to go for it anyway.

All  can say is WOW!!!  I am over the top impressed.

I’ve just started my journey into the land of JavaScript for real and am learning things most of you already know.  For example, as the Silicon Valley Code Camp coordinator and web site author, I just recently decided to add a Virtual Earth Map showing attendees and speakers (see the home page).  I wrote a simple web response handler that returns all the data in JSON so I could plot the data.  Then, after a couple searches on the web, I found a way to send a request to the service asynchronously and get the result. The code looks something like this:

I’ve just started (within the past 2 days) learning and building a prototype with Microsoft’s new MVC platform.  It’s really just another project type in Visual Studio 2008, but it changes the way you write asp.net applications.  So far I like it, but I’m still on the honeymoon.  I have not really tried to do anything complex yet, and because it’s new to me, the simple things are still hard.  Scott Guthrie’s posts posts have been helpful, as well as reading a pre-release of Manning’s upcoming book ASP.NET MVC In Action by Jeffrey Palermo, Ben Scheirman and Jimmy Bogard.

As a moderator in the asp.net forums, I often see the same or similar questions.  The answer to this question is pretty straight forward but not 100% obvious so I thought I’d do a post about in the hopes that with a couple key words, people will find the answer.  The title basically says it all.  We have a GridView that has a data column of type bool.  We want to display in the GridView Yes or No depending on whether the data value is true or false.  The example I’m showing does not help with making this an editable field (maybe a theme for another post if this one is popular) but simply shows yes or no.

The solution involves first dropping a GridView and ObjectDataSource onto your design surface in Visual Studio.  Then, using the little chevron on the GridView, choose edit columns and convert the column you are interested in making a DropDownList into a template.  From there replace the ItemTemplate with the DropDownList code below.  You get the code below.

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

</script>

<html xmlns="http://www.w3.org/1999/xhtml">

<head runat="server">

    <title>ODS DDL Example</title>

</head>

<body>

    <form id="form1" runat="server">

    <div>

        <asp:ObjectDataSource ID="ObjectDataSource1" runat="server" SelectMethod="GetMembers"

            TypeName="BusinessObject"></asp:ObjectDataSource>

        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="Id"

            DataSourceID="ObjectDataSource1">

            <Columns>

                <asp:BoundField DataField="Id" HeaderText="Id" ReadOnly="True" SortExpression="Id" />

                <asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />

                <asp:BoundField DataField="Email" HeaderText="Email" SortExpression="Email" />

                <asp:TemplateField HeaderText="Approved" SortExpression="Approved">

                    <ItemTemplate>

                        <asp:DropDownList ID="DropDownListUser" runat="server" AutoPostBack="False" 

                            SelectedValue='<%# Bind("Approved") %>'>

                            <asp:ListItem Text="Yes" Value="True"></asp:ListItem>

                            <asp:ListItem Text="No" Value="False"></asp:ListItem>

                        </asp:DropDownList>

                    </ItemTemplate>

                </asp:TemplateField>

            </Columns>

        </asp:GridView>

    </div>

    </form>

</body>

</html>

And, when you run this code (assuming you have a simple business object that returns some data), you get this:

Hope this helps!

This past Wednesday, June 25th 2008, I did a presentation titled “Building High Performance ASP.NET Web Applications” to the Bay Area Association of Database Developers (BAADD).  Through out the presentation, I showed an application in Visual Studio 2008.  I’m including that project file here as well as the power point slides used in the demonstration.

And the Power Point Presentation:

Any Questions, feel free to contact me at http://peterkellner.net/contact/