If you want to do this, don´t use autoincrementing integers! ;o) Use UUID instead. (or implement an stand alone id-server that handles autoincrement savely)
As our launch date approaches, I am getting increasingly nervous about Cassandra tuning. It is a mysterious black art that I haven't mastered even at the low usages that we have now. I know of a few more things I can do to improve things, but how will I know if it is enough? All this is particularly ironic since - as we are just starting out - we don't have scalability problems yet, though we hope to!
Luckily, I have completely wrapped Cassandra in an entity mapper, so that I can easily trade in something else, perhaps temporarily, until we really need Cassandra's scalability.
So, I'm thinking of emulating Cassandra with mySQL. I would use mySQL either as a simple key-value store, without joins, or map Cassandra supercolumns to mySQL columns, probably of type CLOB.
Does anyone want to talk me out of this?