One more point, if you are worried about high memory usage then read about disk_access_mode configuration of Cassandra. By default it will cause high memory usage. Setting it to mmap_index_only can help.
On Sat, Apr 11, 2020 at 5:43 PM Laxmikant Upadhyay <laxmikant....@gmail.com> wrote: > 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 > > -- regards, Laxmikant Upadhyay
