Performance Cassandra 1.0

Question

Is there a restriction for column families per cluster / keys beyond which cassandra's performance will decrease significantly? I know that we had problems with earlier versions, and for some reason, reducing the number of column families solved the problem.

Answer 1

See http://www.datastax.com/dev/blog/whats-new-in-cassandra-1-0-improved-memory-and-disk-space-management , which says:

"Cassandra 1.0 uses only one memtable parameter: memtable_total_space_in_mb (located in cassandra.yaml), which defaults to 1/3 of your JVM heap. Cassandra manages this space in all of your ColumnFamilies and flushes memtables to disk as needed. This was for work hundreds or even thousands of ColumnFamilies. "

see also

• http://wiki.apache.org/cassandra/StorageConfiguration
• http://wiki.apache.org/cassandra/MemtableSSTable