No, the point is that it's the same memory that would be cached anyway if you were using non-mmap'd I/O.
This will be more obvious once you have say 10x more data (and SHR) than you have ram (and RES). On Mon, Jul 18, 2011 at 10:27 AM, JKnight JKnight <beukni...@gmail.com> wrote: > Thank for your response. > Can we reduce that value? Memory is used just 600M but the process occupy > 3.2G. Too waste. > > On Mon, Jul 18, 2011 at 6:53 PM, Jonathan Ellis <jbel...@gmail.com> wrote: >> >> That means that the mmaped files are indeed resident at the moment. >> >> On Mon, Jul 18, 2011 at 1:51 AM, JKnight JKnight <beukni...@gmail.com> >> wrote: >> > Thank for your response. >> > Do you talk about virtual memory (column VIRT show in top command)? >> > But I mention about column RES. In my case, VIRT is 61.8G, RES is 3.2G >> > and >> > SHR is 1.2G. >> > JMX show Memory Usage: >> > Used : 600MB, Commit 2.1G, Max: 2.1G >> > On Mon, Jul 18, 2011 at 11:59 AM, Jonathan Ellis <jbel...@gmail.com> >> > wrote: >> >> >> >> http://wiki.apache.org/cassandra/FAQ#mmap >> >> >> >> On Sun, Jul 17, 2011 at 11:54 PM, JKnight JKnight <beukni...@gmail.com> >> >> wrote: >> >> > Dear all, >> >> > I use JMX to monitor Cassandra server. >> >> > Heap Memory Usage show: >> >> > Used : 600MB, Commit 2.1G, Max: 2.1G >> >> > But htop show Cassandra process consume 3.1G. >> >> > Could you tell me why Cassandra occupy memory very large than in >> >> > used? >> >> > Thank a lot for support. >> >> > -- >> >> > Best regards, >> >> > JKnight >> >> > >> >> >> >> >> >> >> >> -- >> >> Jonathan Ellis >> >> Project Chair, Apache Cassandra >> >> co-founder of DataStax, the source for professional Cassandra support >> >> http://www.datastax.com >> > >> > >> > >> > -- >> > Best regards, >> > JKnight >> > >> >> >> >> -- >> Jonathan Ellis >> Project Chair, Apache Cassandra >> co-founder of DataStax, the source for professional Cassandra support >> http://www.datastax.com > > > > -- > Best regards, > JKnight > -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com
