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From Stanislav Lukyanov <stanlukya...@gmail.com>
Subject RE: Runtime.availableProcessors() returns hardware's CPU count whichis the issue with Ignite in Kubernetes
Date Tue, 26 Dec 2017 16:39:24 GMT
Hi Arseny,

Both OpenJDK and Oracle JDK 8u151 should do.
I’ve checked and it seems that it is indeed about the specific way of invoking Docker. By
default it doesn’t restrict container to particular CPUs, but you can make it do that by
using `--cpuset-cpus` flag.

Example:
Without cpuset (Docker host has 4 CPUs)
    >docker run -it java-docker bash
    root@8a2cd9d06695:/usr/test# java -version
    openjdk version "1.8.0_151"
    OpenJDK Runtime Environment (build 1.8.0_151-8u151-b12-0ubuntu0.16.04.2-b12)
    OpenJDK 64-Bit Server VM (build 25.151-b12, mixed mode)
    root@8a2cd9d06695:/usr/test# jjs
    jjs> print(java.lang.Runtime.runtime.availableProcessors());
    4

With cpuset specifying the first two CPUs
    >docker run -it --cpuset-cpus=0,1 java-docker bash
    root@7c2723a9819e:/usr/test# jjs
    jjs> print(java.lang.Runtime.runtime.availableProcessors());
    2

Note also that by using cpuset you change the settings for the whole container, not just for
the Ignite, so that other Java pools in the same JVM, e.g. parallel stream executor, should
also work better.

Unfortunately, I’m not familiar with Kubernetes, but the manual [1] says that you can enable
the use of cpusets via a static CPU management policy.

Hope that helps,
Stan

[1] https://kubernetes.io/docs/tasks/administer-cluster/cpu-management-policies/

From: Arseny Kovalchuk
Sent: 26 декабря 2017 г. 17:37
To: user@ignite.apache.org
Cc: dev@ignite.apache.org
Subject: Re: Runtime.availableProcessors() returns hardware's CPU count whichis the issue
with Ignite in Kubernetes

Hi Stanislav.

We use OpenJDK and use Alpine Linux based images. See java version below. In our environment
availableProcessors returns CPU's for the host. 

Did you mean to try Oracle's JDK 8u151?
arseny@kovalchuka-ubuntu:~/kipod-x$ ku exec ignite-instance-0 -ti bash
bash-4.4# java -version
openjdk version "1.8.0_151"
OpenJDK Runtime Environment (IcedTea 3.6.0) (Alpine 8.151.12-r0)
OpenJDK 64-Bit Server VM (build 25.151-b12, mixed mode)
bash-4.4# jjs
jjs> print(java.lang.Runtime.runtime.availableProcessors());
40
jjs> 



​
Arseny Kovalchuk

Senior Software Engineer at Synesis
skype: arseny.kovalchuk
mobile: +375 (29) 666-16-16
​LinkedIn Profile​

On 26 December 2017 at 16:56, Yakov Zhdanov <yzhdanov@gridgain.com> wrote:
Ilya, agree. I like IGNITE_AVAILABLE_CPU more.


Yakov Zhdanov,
www.gridgain.com

2017-12-26 16:36 GMT+03:00 Ilya Lantukh <ilantukh@gridgain.com>:
Hi Yakov,

I think that property IGNITE_NODES_PER_HOST, as you suggested, would be confusing, because
users might want to reduce amount of available resources for ignite node not only because
they run multiple nodes per host, but also because they run other software. Also, in my opinion
all types of system resources (CPU, memory, network) shouldn't be scaled using the same value.

So I'd prefer to have IGNITE_CONCURRENCY_LEVEL or IGNITE_AVAILABLE_PROCESSORS, as it was originally
suggested.

On Tue, Dec 26, 2017 at 4:05 PM, Yakov Zhdanov <yzhdanov@apache.org> wrote:
Cross-posting to dev list.

Guys,

Suggestion below makes sense to me. Filed a ticket
https://issues.apache.org/jira/browse/IGNITE-7310

Perhaps, Arseny would like to provide a PR himself ;)

--Yakov

2017-12-26 14:32 GMT+03:00 Arseny Kovalchuk <arseny.kovalchuk@synesis.ru>:

> Hi guys.
>
> Ignite configures all thread pools, selectors, etc. basing on Runtime.availableProcessors()
> which seems not correct in containerized environment. In Kubernetes with
> Docker that method returns CPU count of a Node/machine, which is 64 in our
> particular case. But those 64 CPU and their timings are shared between
> other stuff on the node like other Pods and services. Appropriate value of
> available cores for Pod is usually configured as CPU Resource and estimated
> basing on different things taking performance into account. General idea,
> if you want to run several Pods on the same node, they all should request
> less resources then the node provides. So, we give 4-8 cores for Ignite
> instance in Kubernetes, but Ignite's thread pools are configured like they
> get all 64 CPUs, and in turn we get a lot of threads for the Pod with 4-8
> cores available.
>
> Now we manually set appropriate values for all available properties which
> relate to thread pools.
>
> Would it be correct to have one environment variable, say
> IGNITE_CONCURRENCY_LEVEL which will be used as a reference value for those
> configurations and by default equals to Runtime.availableProcessors()?
>
> Thanks.
>
> ​
> Arseny Kovalchuk
>
> Senior Software Engineer at Synesis
> skype: arseny.kovalchuk
> mobile: +375 (29) 666-16-16
> ​LinkedIn Profile <http://www.linkedin.com/in/arsenykovalchuk/en>​
>



-- 
Best regards,
Ilya




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