Now, at the time they were doing peak 2000 tweet/s. The fan-out was 1.2M deliveries a second... So if we go with the current 600:1 ratio at 7000/s, that's about 4.2M/s. I actually know it's much higher now since I work there but other things to consider is we have a large data warehouse, search, API, pipelines to external parties for the firehose, logging at terabytes an hour, in-house metric collection doing 3M writes/s, etc.
http://www.slideshare.net/nkallen/q-con-3770885
Now, at the time they were doing peak 2000 tweet/s. The fan-out was 1.2M deliveries a second... So if we go with the current 600:1 ratio at 7000/s, that's about 4.2M/s. I actually know it's much higher now since I work there but other things to consider is we have a large data warehouse, search, API, pipelines to external parties for the firehose, logging at terabytes an hour, in-house metric collection doing 3M writes/s, etc.
http://www.scribd.com/doc/59830692/Cassandra-at-Twitter
It add's up very fast.