I think there is some potential yak shaving to worrying excessively about swap.
The reality is that you should know the memory demands of what you are running
on your C* nodes and have things configured so that significant swap would be a
highly abnormal situation.
I'd expect to see excessive
I usually recommend following document:
https://docs.datastax.com/en/dse/5.1/dse-dev/datastax_enterprise/config/configRecommendedSettings.html
- it's about DSE, but applicable to OSS Cassandra as well...
Kunal at "Thu, 16 Apr 2020 15:49:35 -0700" wrote:
K> Hello,
K>
K> I need some suggesti
> On Apr 16, 2020, at 5:50 PM, Dor Laor wrote:
>
> You should configure swap for safety, better be slow than crash,
>
For most production use cases, it’s almost always better to crash than be slow.
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On Thu, Apr 16, 2020 at 5:09 PM Kunal wrote:
>
> Thanks for the responses. Appreciae it.
>
> @Dor, so you are saying if we add "memlock unlimited" in limits.conf, the
> entire heap (Xms=Xmx) can be locked at startup ? Will this be applied to all
> Java processes ? We have couple of Java program
Thanks for the responses. Appreciae it.
@Dor, so you are saying if we add "memlock unlimited" in limits.conf, the
entire heap (Xms=Xmx) can be locked at startup ? Will this be applied to
all Java processes ? We have couple of Java programs running with the same
owner.
Thanks
Kunal
On Thu, Apr
It is good to configure swap for the OS but exempt Cassandra
from swapping. Why is it good? Since you never know the
memory utilization of additional agents and processes you or
other admins will run on your server.
So do configure a swap partition.
You can control the eagerness of the kernel by t
Cassandra attempts to lock the heap at startup, but all the memory allocated
after startup is not locked. So you do want to make sure the allowed locked
memory is large.
Disabling or vastly dialing down swappiness is a best practice for all server
software, not just Cassandra, so you should s
Swap is controlled by OS and will use it when running short of memory. I don’t
think you can disable at Cassandra level
Regards,
Nitan
Cell: 510 449 9629
> On Apr 16, 2020, at 5:50 PM, Kunal wrote:
>
>
> Hello,
>
> I need some suggestion from you all. I am new to Cassandra and was reading
Hello,
I need some suggestion from you all. I am new to Cassandra and was reading
Cassandra best practices. On one document, it was mentioned that Cassandra
should not be using swap, it degrades the performance.
My question is instead of disabling swap system wide, can we force
Cassandra not to
