OK, everything should be all good now ... I'll update this post with more details shortly ...
Firstly the DDoS:It started about 20 minutes after the block - at approximately (29th) 18:54 UTC
It was effective for almost 40 minutes.
According to the data centre, it was too small to trigger the base DDoS protection so until they manually intervened it was successful.
I'll look into their "more expensive" option to make it "always work" ... ... ... yeah even writing that sentence myself makes me wonder what that means ... ... ...
Server down time:I was able to get into the server while the DDoS was happening due to how I have certain things configured ... details withheld
I actually shut everything down on the server, upgraded everything, rebooted the server and started all back up.
I started this (coincidentally) just at the end of the DDoS so although some miners may have eventually connected towards the end of the DDoS, they will have been disconnected shortly after.
Taking everything down correctly in order, upgrading everything, rebooting and restarting everything in order took me about half an hour - so I now know that time length, for future reference, if I need to plan that (ahead) some time in the distant future.
The dependency on each process starting and connecting is such that I prefer that all to be a manual process so I know that the final step of ckpool starting means that all miners will be mining valid work and not throwing hashes away.
There are all sorts of possible problems with starting everything automatically that I prefer to not have mining available until I'm sure it is all OK.
If it hasn't been obvious in the past, I will say it clearly, if the pool isn't running with up-to-date work and a good connection to bitcoin, I don't want miners connected risking wasting their hashes, thus on such occasions I would be stopping the main pool service until it's resolved and not allowing connections.
I don't expect this to happen, or if ever, only for a short time, but that's how I prefer to run it and that's also why (like on any pool) you should always have backup pools.
All should be good now (for the last 35 minutes)
If anyone has any problems connecting - of course let me know - or PM me with your account details
Edit: I've also updated the coinbase payout addresses since it's been more than 100 blocks since the last time I did that.