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Posted to user@cassandra.apache.org by JKnight JKnight <be...@gmail.com> on 2011/07/18 06:54:07 UTC
Cassandra consume large memory
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
Re: Cassandra consume large memory
Posted by Jonathan Ellis <jb...@gmail.com>.
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 <be...@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 <jb...@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 <be...@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 <jb...@gmail.com>
>> > wrote:
>> >>
>> >> http://wiki.apache.org/cassandra/FAQ#mmap
>> >>
>> >> On Sun, Jul 17, 2011 at 11:54 PM, JKnight JKnight <be...@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
Re: Cassandra consume large memory
Posted by JKnight JKnight <be...@gmail.com>.
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 <jb...@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 <be...@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 <jb...@gmail.com>
> wrote:
> >>
> >> http://wiki.apache.org/cassandra/FAQ#mmap
> >>
> >> On Sun, Jul 17, 2011 at 11:54 PM, JKnight JKnight <be...@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
Re: Cassandra consume large memory
Posted by Jonathan Ellis <jb...@gmail.com>.
That means that the mmaped files are indeed resident at the moment.
On Mon, Jul 18, 2011 at 1:51 AM, JKnight JKnight <be...@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 <jb...@gmail.com> wrote:
>>
>> http://wiki.apache.org/cassandra/FAQ#mmap
>>
>> On Sun, Jul 17, 2011 at 11:54 PM, JKnight JKnight <be...@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
Re: Cassandra consume large memory
Posted by JKnight JKnight <be...@gmail.com>.
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 <jb...@gmail.com> wrote:
> http://wiki.apache.org/cassandra/FAQ#mmap
>
> On Sun, Jul 17, 2011 at 11:54 PM, JKnight JKnight <be...@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
Re: Cassandra consume large memory
Posted by Jonathan Ellis <jb...@gmail.com>.
http://wiki.apache.org/cassandra/FAQ#mmap
On Sun, Jul 17, 2011 at 11:54 PM, JKnight JKnight <be...@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