freemind blogs » asp.net

Beware of Windows Server 2008 Network Optimization

james — Fri, 06 Mar 2009 15:48:03 +0000

Problem:

Recently I was migrating some Windows Server 2003 applications to new hardware and Windows Server 2008. The applications were mostly simple ASP.NET applications using either NHibernate or ADO.NET to communicate to a Windows Server 2003 x64 box running Sql Server 2005sp3.

Each of the new Win2k8 machines were having performance issue retrieving data from the database. After firing up Sql Profiler I was able to see that executing a simple statement like “SELECT * FROM Store” was taking over 5sec to return 40 rows. The slowness was the same in both ADO.NET and NHibernate apps. More research from that the WinForms apps running as admin were having the same issues. And executing the queries in SSMS showed same behavior.

So Win2k3 servers talking to the same database are running fast. Blowing my mind I found that using the Win2k8 servers to connect to a different Sql Server 2005sp2 on 32bit runs just fine (no delays). That’s right I can load the data onto a different server and see no delays!

If you are reading this you might be starting to form some theories. Both the Win2k3 and Win2k8 servers are on the same subnet.

At this point I requested help from the smart support guys from Microsoft. We verified that the Sql execution plans were not changing. We also verified the network settings on the database, Win2k3, and Win2k8 servers.

Next step netmon. After capturing and reviewing the netnom logs we were able to see that there were packets getting fragmented and there were long delays in sending the secondary packets. There are many newer features in Win2k8 to optimize the network performance (receive side scaling, tcp chimney offload, network direct memory access, and autotuning). Learn more here: http://support.microsoft.com/kb/951037

Root Cause:

In my situation the autotuning feature was trying to adjust the tcp receive window (RWIN) and was timing out waiting for an acknowledgment from the database server. It is possible that the router was holding onto the response packet, I wasn’t able to completely correlate all the send/receives.

Learn more about RWIN behavior here: http://www.nerdgrind.com/speed-up-windows-vista-network-performance-with-tcp-windows-tuning/2/

Resolution:

It is possible that we could have reconfigured the router to increase the frame sizes to prevent the packet fragmentation. It is also possible that change could have hidden the delays

The way I choose to resolve the issue was to turn off the autotuning with the following statement:

netsh interface tcp set global autotuning=disabled

Some network card drivers have the ability to control this setting via the advanced properties.

Why the hell am I still forced to type runat=”server” after all these years?

Ira Mitchell — Sun, 24 Aug 2008 19:46:32 +0000

We’ve all seen the Microsoft guys stumble over this time and time again in demos. Why are we still forced to add this? I mean, if it’s a server control (the control starts with “

Why is runat=”server” not the default condition?

Using Email Templates With ASP.NET

james — Mon, 07 Jul 2008 21:41:33 +0000

Somedays working with ASP.NET can be a treat. Especially on those days when you stumble upon some functionality you had no idea existed.

It seems like every website has some need to generate emails for things like order confirmation, password resets, or news updates. System.Net.Mail provides excellent functionality for building email messages and communicating with SMTP servers. But it is up to the developer to build the actual content of the message programmatically, usually by using a StringBuilder to concatenate a bunch of user-specific and common strings.

Turns out there is class and technique that can simplify that code quite a bit. MailDefinition is a class that allows you to build email templates and easily update the dynamic parts.

Check out the following code:

public void GenerateOrderEmailCustomer(Order order)
{
try
{
MailDefinition template = new MailDefinition();
template.BodyFileName = "~/templates/CustomerOrderConfirmation.html";
template.From = order.Store.Retailer.ApplicationConfig.EmailOrderFromAddress;

Dictionary<string, string> data = new Dictionary<string, string>();
data.Add("<>", order.OrderNumber.ToString());
data.Add("<>", order.Store.Name);
data.Add("<>", order.Status.ToString());
data.Add("<>", order.FirstName);
data.Add("<>", order.LastName);
data.Add("<>", order.Address1);
data.Add("<>", order.Address2);
data.Add("<>", order.City);
data.Add("<>", order.State);
data.Add("<>", order.Zip);
data.Add("<>", order.PaymentMethod.ToString());
data.Add("<>", (order.Payment != null) ? order.Payment.CardHoldersName:"n/a");
data.Add("<>", (order.Payment != null)? order.Payment.CardType:"n/a");
data.Add("<>", (order.Payment != null) ? order.Payment.CreditCardNumber.Substring(0, 4) + " **** **** ****" : "n/a");

string detailTable = "";
foreach (OrderDetail detail in order.Details)
{
detailTable += string.Format("{0}{1}", detail.Quantity, detail.Name);
}

data.Add("<>", detailTable);
data.Add("<>", "http://www.wineconnect.com/");

MailMessage message = template.CreateMailMessage(order.Email, data, new LiteralControl());
message.IsBodyHtml = true;
message.Subject = string.Format("Order Confirmation: {0} ({1})", order.Store.Name, order.OrderNumber.ToString());

SmtpClient client = new SmtpClient(order.Store.Retailer.ApplicationConfig.EmailServer, order.Store.Retailer.ApplicationConfig.EmailPort);

//Enable SSL
client.EnableSsl = order.Store.Retailer.ApplicationConfig.EmailEnableSsl;

client.UseDefaultCredentials = false;
client.Credentials = new NetworkCredential(order.Store.Retailer.ApplicationConfig.EmailUsername, order.Store.Retailer.ApplicationConfig.EmailPassword);

client.SendCompleted += new SendCompletedEventHandler(MailDeliveryComplete);
client.SendAsync(message, message);
}
catch (Exception ex)
{
_log.Error("Error caught while sending customer order confirmation", ex);
}
}

Combined with this template:

<html>
<head>
<title>Order Confirmation</title>
</head>
<body>
<table width="400" border="1" cellpadding="4" cellspacing="0" bordercolor="EDF5E3">
<tr bgcolor="#999999" >
<td align="center" style="height: 16px">Order Confirmation (<>)</td>
</tr>
<tr><td>
<>, 
This email confirms your order: 
Store: <> 
Order Status: <> 
 Billing Information: 
Customer: <> <> 
Address1: <> 
Address2: <> 
City: <> 
State: <> 
Zip: <> 
 Payment Method: <> 
Card Holder: <> 
Card Type: <> 
Card Number: <> 
Order Information:
<table class="messageTxt"><tr><td>Qty.</td><td>Item</td></tr>
<>
</table> 
Your order number is <a href='<>/OrderSummary.aspx?OrderNumber=<>'><></a>.
Please feel free to contact us with any questions or visit our website if you need directions to our store. 
<a href="<>"><></a> 
Thank you, Wine Store Dudes </td></tr>
</table>
</body>
</html>

It generates this email:

Good Stuff:

Using this technique I was able to get rid of a bunch of string concatenation and string.Format code. The template should be much easier to maintain going forward.

Lame:

The way MailDefinition replaces the dynamic tokens is nice but a bit limiting. It might be fun to try using a Server.Execute method to pick up other ASP.NET goodness like data binding and advanced logic.

The CreateMailMessage function also requires a OwnerControl to be passed in. They could have given us an overloaded version that didn’t require this because I doubt anyone ever uses it.

The ASP.NET Wiki. Microsoft Doesn’t Get It.

Ira Mitchell — Fri, 16 May 2008 16:16:09 +0000

I fired up the quite excellent Visual Studio today to do a little of what I do every day. In this case, as I was waiting for my project to load I noticed a link to “New Updates to the ASP.NET Wiki”. It’s been awhile since I visited the ASP.NET Wiki (likely around its February 2008 release) and this seemed like something I should at least take a look at again.

…and it was almost exactly what I expected. Generic, awful-looking crap — with ads. It couldn’t be any more proto-typically Microsoft if they’d attached a signature 2007 or two-alpha-character suffix. I’m sure someone lobbied for Wiki.NET 2007 NT.

I’m a bit more keen on design aesthetics than most hard-core developers. Just a bit more interested in the user’s perspective and the utility of an application than whether it is using straight ADO.NET, the (dated) Data Access Application Block, nHibernate, or any other ORM to get data to user (and back again). As long as it works, isn’t too messy, and is snappy enough to deal with the load, I’m fine with it.

So, I start digging through and like most of the Microsoft properties, there is some good stuff in here. Much of the content is really solid and functionally, it’s worthy of a passing grade — if I could just see my red pen through the blood pooling in my eyes. I start to feel a bit congested and my blood-pressure starts to rise searching for content. There are navigation elements, and lists of links sprayed all over the page like… have you ever tried that acoustic ceiling spray in a can? If you have, you know what I mean. If you haven’t I beseech you to give it a try (NOTE: heed ALL warnings on the can).

But I digress. Here is a screenshot of the ASP.NET Wiki:

Right off the bat, the ads are both offensive and totally out of place. Maybe it’s me, but any time I see a graphical smiley, in the wild or in an ad, I immediately think I entered the wrong URL into the browser. It’s shocking. The disregard for white space is apparent throughout, but not so much as on the asp.net homepage.

If you’re running your browser at less than 1080 pixels wide, you’re going to see the following start to happen. I initially thought it was me and gratuitous use of the Firefox browser, but no, you’ll see the same thing in IE7. God help you if you’re stuck on that piece of garbage, 1024 x 768 development laptop you’ve been assigned at Super GloboMax Worldwide Incorporated (or Target Corporation).

Again, the content is decent — if you can work your way through the phlegm.

Straight out of MinneRails, er, I mean Minnebar last weekend, I thought to myself, “Self, I wonder what the Rails Wiki looks like.”

It’s as good as the ASP.NET one is bad. Simple, elegant layout. Easy to navigate. The internal pages are even better.

One step further and you see what the actual content looks like.

There is the information I want. The sparseness is wonderful, isn’t it? I want to cuddle with this ad-free, feature-rich, information-packed, easily-navigable, simple wiki — and I don’t do Rails.

I have three things to offer to Microsoft, the team behind the ASP.NET wiki (Scott Hanselman, Telligent), and really anyone trying to build a community around a product they are selling or supporting. First, just because you are a for-profit entity, doesn’t mean you need to monetize every single page of your content with banner ads or the google equivalent. Communities work better and (maybe this is where Microsoft is missing the boat) feel more natural if as a member you’re not constantly being marketed to. Secondly, use the right tool for the job. I know SharePoint and the .NET-based portals are going to be your first choice based on the user base, but are they the best bet? Not by a long shot for something like this. Thirdly, I see (the very google-esque) “beta” in the wiki title. Please consider some serious changes before this becomes “production code”.

Maybe a tool like ScrewTurn Wiki is a better option. At the very least it would be a refreshing change to this nightmare.