Can we get a pic of the blockchain.info server rack? Just curious as to what this all looks like.
Here is a photo of the rack https://i.imgur.com/wMFG1.jpg. We do not have a full rack to ourselves yet.
3 mac mins (top) - 4 servers in one chassis (middle) - firewall & intrusion detection (bottom).
They are not really ddos attacks which a company like that would be able to help with. It is more just a few dozen tor ip addresses causing problems. For example one ip opening 1000's of websocket connections, or generating huge numbers of forwarding addresses.
I would have never tought to ask this here but hey why not... How do you find NDB to be? What kind of query/second can you handle? Are you keeping the whole database on ram or indexes only? I was always interested in it but always ended up with other solutions!
It is entirely in ram. The site averages about 200-300 queries / second which isn't anything particularly special but cpu usage of ndb averages about 20%, considering this is decent 4 server cluster I feel like the load should be lower. However I haven't benchmarked it against any other database so I don't know if it really is an ndb problem or poor schema/query design. On the plus side it's pretty stable, I think before the recent maintenance it ran for 100 consecutive days without problems. In future I imagine moving to something like HBase/Cassandra but not for a while yet.
