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Using ServerXMLHTTP instead of XMLHTTP to Talk to Authorize.Net

Published to Blog on 11 Aug 2004

Re: my ASP101 article about using ASP and XMLHTTP to talk to Authorize.Net

That article was published a little over two years ago.  I have received lots of feedback and questions.  Among those I have also had a few people tell me that I should use ServerXMLHTTP rather than XMLHTTP, it scales better.

I really need to update that article, but in the mean time, I am posting the text of an email I received today from Eddie Barcellos of

I found your article while searching for any instance of someone using XMLHTTP to talk to authnet. I should let you know that XMLHTTP uses the same HTTP stack as IE does (, which is limited to 2 connections. The solution is to use ServerXMLHTTP. We found out about this the hard way: the server started to get a lot of “event ID: 37 source: w3svc” errors, and in a few minutes it would bring the server down.

FYI, since there is really no downside in using ServerXMLHTTP instead of XMLHTTP, and Authnet is such a critical part (i could say the most critical) of the user’s path thru the site, you might want to change the article to show use of the appropriate component.

Eddie also mentioned that he would love to talk to others who are using ServerXMLHTTP to talk to Authnet, he is having some problems with V4 of the component.

If you are using ServerXMLHTTP to talk to Authorize.Net and are either having problems or are problem free please leave a comment and/or email address.  Eddie, feel free to leave your contact information if you would like, as well.

Dan Hounshell
Web geek, nerd, amateur maker. Likes: apis, node, motorcycles, sports, chickens, watches, food, Nashville, Savannah, Cincinnati and family.
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