Hopefully this is the right place to post this. Why am I writing this post? I've been lurking around for a while and wanted to give something back, if I can. Drop Catching is one of those things no one in the domain world wants to talk about. Well they won’t talk about their scripts! Why would they? It would be like Coke giving up their magic recipe. So far it has been a 5 week project and I have lost count of how many hours it’s taken (and continue to take). It is still in development and currently off-line. Every day I tweak code, measure code speed and fine tune socket communication. It’s amazing how many hours you can spend measuring and analysing milliseconds. Okay, I am not going to give you any code but here are some things that I have learnt. My software is currently written in C#, but I might move to C++ if it will provide faster timings. I am sure it won’t and hopefully below will explain why. I will say up front, I do not know anyone here or anyone that Drop Catches, so I’ve been working in the dark. It’s been fun stumbling around trying to understand how it all works. To be honest it is surprising basic. The process: Repeatability query DAC for domain availability If domain drops send EPP create request My average timings: These times can vary, not by a lot, but they do vary. The reason your timings will vary will be due to network loads at your data centre and those at Nominet. Nominet’s systems are going to be the slowest part of the system, so be careful what the time of day you test! Sending DAC query 0.0015ms Receiving DAC query 0.0020ms Sending EPP Request 0.05ms Receiving EPP Request 60ms From drop notification to send EPP Request 0.0002ms Receiving the response back from the EPP is slow. I can only imagine their server is a) under load and b) their XML parsing and writing is probably not optimised. There is also a delay on the EPP communication due to the secure socket layer, so encryption is important here. Servers – Good Network The golden 2ms from Nominet. I have so far found it hard to be that slow, my DAC send and receive is 350 ticks. I have read this a lot, services boasting about being close to Nominet. Based on my tests, some network monitoring and the above timings Nominet’s servers and coding is your barrier. That is not to say you shouldn’t aim to buy or rent a server on a good network. Servers – High Spec You don’t need to high spec machine. Depending on how it is written, your code will probably only run 4 to 6 threads. I’m running a Windows 2008 Quad Core server with 2GB ram and an 80Gb hard drive. Any more would be a waste. Servers – Only Run Essentials Only run services that are required, turn everything else off. You don’t want your operating system starting threads the take priority over yours. Optimising your code and keep track Keep tweaking your code and never settle for working. I spent one hour rewriting the EPP socket and managed half communication time. Compress data. Remove variables and method calls that are not necessary. Keep yourself connected. Log your transactions, code executions but more importantly your exceptions. Recover from failure; no one likes a site down SMS at 3am! Remember to turn your logging off when live. Finally are you feeling lucky? If you base your calculations someone’s system EPP request send taking 5ms (which is slow but possible) you are only as good as your last loop. If your scan intervals are every 200ms and the domain hasn’t dropped you have 199ms before the next check. That’s a long time for other systems to have checked before that next check. Too long! Even at the maximum 60ms intervals, you’ll probably still miss the domain if it drops between scans. It’s all about luck, you have to hope your system pings just at the right time. I don’t have time tonight but I could also talk about strategy - 60ms, 200ms, multi-checks, blasting, etc. Probably open that one for discussion.