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Dawn Parzych

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Top Stories by Dawn Parzych

Being the total acceleration junkie that I am the first time a new site is launched or recommended to me the first thing I do is take a look at the performance of it.  So when I heard about Bing the first thing I did was fire up HttpWatch and take a look at the site.  To make things a little more interesting I decided to compare the results to Google, I used the classic home page and not my customized iGoogle home page. Tests were conducted from my home broadband connection in London, England.  Each test was done with a fresh instance of the browser and with an empty browser cache.  I did access the sites multiple times to make sure that there were no anomalies (which there weren't)  below are the results from one test run.  What was I searching for - ME!   Bing Google Number of Objects 11 11 Total Home Page Size 114K 52K Total Download Time for Home Page 3.2 second... (more)

A Brief History of TCP

The foundation of the Internet is TCP, it includes the rules for formatting messages, handling congestion, error correction and provides information on where a packet should be delivered, whether it arrived too quickly for the receiving computer and whether it arrived at all. Basically TCP is the glue that ensures network conditions work smoothly. As the way people connect to the internet has changed from 2400 baud modems to high speed fiber to the home and mobile connectivity – TCP is being stretched to perform optimally across multiple channels. It seems like for many years dev... (more)

What are you waiting for?

The future of HTTP is here, or almost here.   It has been 5 years since SPDY was first introduced as a better way to deliver web sites.  A lot has happened since then.  Chrome, Firefox, Opera and some IE installations support SPDY. SPDY evolved from v2 to v3 to v3.1. Sites like Google, Facebook, Twitter, and Wordpress to name just a few are available via SPDY. F5 announced availability of a SPDY Gateway. The IETF HTTP working group announced SPDY is the starting point for HTTP/2. And most recently - Apple has announced that Safari 8, due out this fall,  will support SPDY!  This ... (more)

v10 WebAccelerator and iRules

A customer recently contacted me regarding an iRule that worked in v 9.4 but did not produce the expected results in v 10.  A little research revealed that the new plug-in architecture is influencing when the iRule is firing. The iRule The iRule is logging the value of the X-PvInfo header or indicating the header is not present.  when HTTP_RESPONSE {   if {[HTTP::header exists X-PvInfo]}{    log local0. "X-PvInfo:[HTTP::header "X-PvInfo"]"   } else {    log local0. "did not find X-PvInfo header"   } } The Problem WebAccelerator inserts the X-PvInfo header into each and every respons... (more)

Acceleration ABCs - X is for XML

I am frequently asked what can be done to accelerate XML.  There are two ways an application delivery controller can accelerate XML: Compression - XML is a markup language that is text based.  Text is easily compressible and can result in significant savings.  Dynamic Caching - If the XML is repetitive it can be cached, if each and every XML request is unique then caching is not going to help.  Caching rules can be written based on the URI and request headers, off-loading requests from the origin servers.  Technorati Tags: acceleration,compression,xml Categories: Acceleration , XM... (more)