Hi,
Thank you for posting your requirement.
My name is Inderjeet and own a small 4 member IT services firm based at Chandigarh,India. We have been into IT since 1994 (desktop software), into Web-apps since 2001 and Wowza/FMS based video streaming/VOD apps for about 5 years. We also maintain our clients' servers (mostly linux) on their behalf besides fiddling with our own Linux test bed VPS's and VMs. We have been working on CentOS since 2002 and play with other Linux OS's also for R&D and future purposes (firewalls, network sniffing, mobile development, ethical hacking etc). We're Currently exploring International clients through these portals for mutually beneficial and long lasting collaborations.
I was not clear if the dns has to be checked from your mysql db or publicly. I think you are trying to capture dropped or expired domains. If yes, the WHOIS servers will not allow that many requests from a single IP as they have bulk query protection, unless you are a registrar yourself. We can give you the script whuch will work, but no guarantee server will not time-out in case of IP block.
Let me know if you have any questions or comments.
Looking forward to a positive response.
Sincerely,
Inderjeet