It's closer to 8x than 2x for small values. Java objects simply use a lot more memory than you'd think, and it takes multiple objects to store a column.
http://kohlerm.blogspot.com/2008/12/how-much-memory-is-used-by-my-java.html On Mon, Mar 28, 2011 at 4:15 PM, ruslan usifov <ruslan.usi...@gmail.com> wrote: > > > 2011/3/29 Narendra Sharma <narendra.sha...@gmail.com> >> >> This is because the memtable threshold is not correct to the last byte. >> The threshold basically account for column name, value and timestamp (or the >> serialized column). It doesn't account for all the in-memory overhead for >> maintaining the data and references etc. > > Overhead in 2 times???? Hm why so many. Also in JMX (throw jconsole) i don't > see any overhead, when memtable reach it memory threshold it will be reset > to very low value (about 300 - 400 KB) > -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com
