A few useful things to remember…

App_Offline.htm

“The way app_offline.htm works is that you place this file in the root of the application.  When ASP.NET sees it, it will shut-down the app-domain for the application (and not restart it for requests) and instead send back the contents of the app_offline.htm file in response to all new dynamic requests for the application.  When you are done updating the site, just delete the file and it will come back online.

One thing I pointed out in the talk that you want to keep an eye on is a feature of IE6 called “Show Friendly Http Errors”.  This can be configured in the Tools->Internet Options->Advanced tab within IE, and is on by default with IE6.  When this is on, and a server returns a non HTTP-200 status code with less than 512 bytes of content, IE will not show the returned HTML and instead substitutes its own generic status code message (which personally I don’t think is super friendly <g>).

So if you use the app_offline.htm feature, you should make sure you have at least 512 bytes of content within it to make sure that your HTML (instead of IE’s friendly status message) shows up to your users.  If you don’t want to have a lot of text show-up on the page, one trick you can use is to just add an html client-side comment with some bogus content to push it over 512 bytes.”

http://weblogs.asp.net/scottgu/archive/2006/04/09/442332.aspx

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Timeouts and String Concatenations

turns out the way i’ve been concatenating strings my whole life is not the most effective one. here is some info:

“If not handled properly, String Concatenation can really decrease the performance of your application. You can concatenate strings in two ways.

• First, by using string and adding the new string to an existing string. However, this operation is really expensive (especially if you are concatenating the string within a loop). When you add a string to an existing string, the Framework copies both the existing and new data to the memory, deletes the existing string, and reads data in a new string. This operation can be very time consuming and costly in lengthy string concatenation operations.
• The second and better way to concatenate strings is using the StringBuilder Class. Below is an example of both approaches. If you are considering doing any type of String Concatenation, please do yourself a favor and test both routines separately. You may be surprised at the results.”

'Concatenation using String Class

Response.Write("<b>String Class</b>")
Dim str As String = ""
Dim startTime As DateTime = DateTime.Now
Response.Write(("<br>Start time:" + startTime.ToString()))
Dim i As Integer
For i = 0 To 99999
str += i.ToString()
Next i
Dim EndTime As DateTime = DateTime.Now
Response.Write(("<br>End time:" + EndTime.ToString()))
Response.Write(("<br># of time Concatenated: " + i.ToString))

while for others something like this may take around 4 minutes – running 100,000 requests this way has timed out my application. no results.

'Concatenation using StringBuilder

 Response.Write("<b>StringBuilder Class</b>")
 Dim strbuilder As New StringBuilder()
 Dim startTime As DateTime = DateTime.Now
 Response.Write(("<br>Start time:" + startTime.ToString()))
 Dim i As Integer
 For i = 0 To 99999
 strbuilder.Append(i.ToString())
 Next i
 Dim EndTime As DateTime = DateTime.Now
 Response.Write(("<br>Stop time:" + EndTime.ToString()))
 Response.Write(("<br># of time Concatenated: " + i.ToString))

This one took less then a second to run.

http://www.codeproject.com/KB/aspnet/ASPNET_Best_Practices.aspx

Tags: asp.net, code, snippets, useful