About ASPAccelerator.NET

Overview

ASPAccelerator is an HTTP Module for Microsoft's ASP.Net web applications, which can reduce the amount of data sent from the server to the client.

Reducing the number of bytes that have to be transferred from the server to the browser (or other client) means less network packets, faster transmission time and quicker performance as well as savings in bandwidth cost.

SSL secured sites benefit even more from the reduced size of the output as the time consuming, dynamic encryption has to be applied to less data. The dynamic (on-the-fly) encryption of SSL works on every byte that leaves the server so reducing the number of bytes output will significantly reduce the amount of work that the server has to perform doing the encryption. The end result is that SSL secured pages operate much faster.

The saving is accomplished using two methods:

Compression

The HTTP protocol used on the web provides for content to be compressed using industry standard compression algorithms and all major browsers since 1998/99 support receiving compressed content which is done transparently to users. The deflate algorithm used for the compression can reduce the size of a typical 100k file by up-to 90% which can result in pages loading at least 2-3 times faster and sometimes more. The differences are more noticeable on slower connections but the improvements depend on the size of the content being sent and the speed of the connection.

Suppression

Traditionally, IIS has checked requests for static content to see whether the content has been changed since the last time it was requested. If it has not changed then the server sends back a "304 Not Modified" response which instructs the browser to display the copy it already has. This is not done for dynamic content, which is why static web sites may often seem a little 'snappier'.

ASPAccelerator can now provide the same benefit to dynamic web applications by using the standard HTTP headers and checking the content produced to see if it has changed from the version the client already has. By suppressing the output when possible even more savings (and performance improvements) can be achieved than compression alone.

At no time does the client display 'old' content such as would happen if the page is just set to be cached locally - if the server output changes at any time then this is sent and displayed as normal.

Usage

The module works transparently to users and requires no code changes to implement. Because it is implemented as an ASP.Net module, there is no need to install anything on the server and it needs no administrator access to implement.

Simply drop the assembly into the applications folder and create the appropriate configuration entries in the web.config file. The configuration options allow complete control over the type and level of compression and whether suppression should be used and flexible URL matching enables these to be overridden for specific requests.