Trying to Create Instant Domain Name Availability Search Using PHP/AJAX

[carbon179]

Hi Everyone --

 

Thanks for taking a look at this.  I've been trying to create a custom developed domain name availability script that instantly checks, as the user types, the top 3 TLDs using AJAX.  This is *exactly like* www.instantdomainsearch.com and www.bustaname.com.

 

The problem:

 

I've found that the most reliable way to do this is query WHOIS databases, the obvious problem with this is that the WHOIS DB's rate limit the # of lookups you can do in a certain period of time - the most restrictive being the WHOIS database for .org domains which limits to 4 per minute.  Not very useful for this type of app.

 

Thus, I've used the php function checkdnsrr() - this checks the existence of a DNS A record -- not the most accurate, but it'll have to do.  The problem is that the performance is very slow -- takes about 2-7 seconds to return a result. 

 

My question: How do the sites I mentioned above work so fast and so well with no perceivable delay in the results?

 

Thanks for any help!

 

-Carbon

 

[premiso]

They probably are using access to a whois database that constantly updates locally. This way all the data is local and updates itself...they also probably pay a pretty good penny for that kind of access to a database or run their own servers to constantly update etc and those servers are dedicated to just that.

 

My 2cents anyhow.