There is another problem. You now need to run repair for a large number of column families and keyspaces and manage that, look out for schema mismatches etc.

On Mon, Jul 1, 2013 at 4:09 PM, Robert Coli <> wrote:
On Mon, Jul 1, 2013 at 9:19 AM, Kirk True <> wrote:
What will it take for C* to support 50,000 column families?

As I understand it, a (the?) big problem with huge numbers of Column Families is that each ColumnFamily has a large number of MBeans associated with it, each of which consume heap. So.. a lot fewer MBeans per column family and/or MBean stuff not consuming heap? Then you still have the problem of each CF having at least one live Memtable, which even if empty will still consume heap...

I'm thinking the real answer to "what it will take for C* to support 50k CFs" is "a JVM which can functionally support heap sizes over 8gb" ... which seems unlikely to happen any time soon.