Hi, You can read section 'OS Page Cache Usage' on http://cassandra.apache.org/doc/latest/troubleshooting/use_tools.html Also, don't worry about memory usage (page cache) not decreasing even if no traffic ...it will come down when required (for example: a new application needs it when boot up).
On Sat, Apr 11, 2020 at 5:29 PM HImanshu Sharma < himanshusharma0...@gmail.com> wrote: > Hi > > I am observing memory usage in top command, but there in RSS it is showing > 18G ( which I think is sum of used memo + page cache). I want to know how > to find how much used by Cassandra process and how much of it is in page > cache. I want this information because I want to check memory usage for > monitoring. > > On Sat, Apr 11, 2020 at 9:42 PM Nitan Kainth <nitankai...@gmail.com> > wrote: > >> You can look at top command. There is column of memory >> >> >> Regards, >> >> Nitan >> >> Cell: 510 449 9629 >> >> On Apr 11, 2020, at 11:10 AM, HImanshu Sharma < >> himanshusharma0...@gmail.com> wrote: >> >> >> Hi >> >> But I see memory not decreasing even if there is no traffic on cluster. >> How can I find actual memory usage by Cassandra process. If it is OS page >> cache then how to find how much is page cache and how much is used by >> process? >> >> Thanks >> Himanshu >> >> On Sat, Apr 11, 2020 at 9:07 PM Laxmikant Upadhyay < >> laxmikant....@gmail.com> wrote: >> >>> It is OS page cache used during read..your os will leverage memory if >>> not being used by any other applications and it improves your read >>> performance. >>> >>> On Sat, Apr 11, 2020, 12:47 PM HImanshu Sharma < >>> himanshusharma0...@gmail.com> wrote: >>> >>>> Hi >>>> >>>> I am very new to the use of cassandra. In a cassandra cluster of 3 >>>> nodes, I am observing memory usage of cassandra process going more than the >>>> heap memor allocated. As I understand, cassandra allocates off heap memory >>>> for bloom filters, index summary etc. >>>> >>>> When I run nodetool info, I see off heap memory usage around 1.5G, my >>>> heap is 8G. So memory usage should not go above 10G. But in running node >>>> it goes as high as 18G with heavy loads. It comes down with different loads >>>> but always more than 12G. >>>> >>>> I would like to know why memory usage is high and is there way to >>>> control it. >>>> >>>> Thanks >>>> Himanshu Sharma >>>> >>> -- regards, Laxmikant Upadhyay
