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From Denis Magda <dma...@apache.org>
Subject Re: Durable Memory and Ignite Persistence Tuning
Date Wed, 13 Sep 2017 19:36:41 GMT
That’s exactly the discussion around that documentation. Feel free to add these useful points
there or wait while I’ll do this later.

—
Denis

> On Sep 13, 2017, at 12:27 PM, Dmitriy Setrakyan <dsetrakyan@apache.org> wrote:
> 
> Completely agree with Nikita. Why not add this information here?
> 
> https://apacheignite.readme.io/docs/durable-memory-tuning
> 
> D.
> 
> On Wed, Sep 13, 2017 at 2:54 AM, Nikita Ivanov <nivanov30@gmail.com> wrote:
> 
>> Excellent work on this... This should be expanded and be prominently placed
>> in our docs/tutorials/javadocs/etc.
>> 
>> --
>> Nikita Ivanov
>> 
>> 
>> On Wed, Sep 13, 2017 at 12:29 PM, Ivan Rakov <ivan.glukos@gmail.com>
>> wrote:
>> 
>>> Folks,
>>> 
>>> We had some experience of benchmarking Ignite with persistent store on
>>> SSD. I think we can share some helpful advice. None of them require
>>> changing configuration of Ignite or persistent store.
>>> 
>>> *Tuning advice for users*
>>> 
>>> 1) Be prepared for LFS performance decrease after several hours of
>>> intensive load. Unfortunately, that's how SSD drives work:
>>> http://codecapsule.com/2014/02/12/coding-for-ssds-part-2-arc
>>> hitecture-of-an-ssd-and-benchmarking/
>>> Consider buying fast production-level SSD drives.
>>> 2) Consider using separate drives for LFS files and WAL. Ignite actively
>>> performs writes to both LFS and WAL under intensive load, and having two
>>> devices will double your throughput limit.
>>> 3) Over-provision your SSD. Performance of random writes on 50% filled
>>> disk is much better than on 90% filled. SSD Over-Provisioning And Its
>>> Benefits: http://www.seagate.com/ru/ru/tech-insights/ssd-over-provisio
>>> ning-benefits-master-ti/
>>> 4) Leave free space in RAM to let OS use page cache and optimize writes.
>>> Total size of all memory policies shouldn't exceed 70% of your RAM.
>>> 5) Make sure that OS doesn't utilize swap. If you use Unix, best option
>> is
>>> set vm.swappiness to 0.
>>> 6) Try to find out page size of your SSD. Ideally, page size of Ignite
>>> shouldn't be less than SSD page size. Possible approaches:
>>> Find it in device specification (some manufacturers don't reveal it)
>>> Try running SSD benchmarks
>>> If you are not sure, just set page size to 4K. As various benchmarks use
>>> 4K pages, manufacturers have to adapt drives for 4K random write
>> workload.
>>> Whitepaper from Intel showing that 4K pages are enough:
>>> https://www.intel.com/content/dam/www/public/us/en/documents
>>> /white-papers/ssd-server-storage-applications-paper.pdf
>>> Check your OS page cache size. Page size of Ignite shouldn't be less than
>>> OS page size. How to check OS cache page size in Unix:
>>> https://unix.stackexchange.com/questions/128213/how-is-page-
>>> size-determined-in-virtual-address-space
>>> 
>>> 
>>> Best Regards,
>>> Ivan Rakov
>>> 
>>> On 01.09.2017 21:08, Denis Magda wrote:
>>> 
>>>> Igniters,
>>>> 
>>>> I see a lot of complains regarding the performance of the subj on the
>>>> user list. At the same time, I do believe that in most scenarios it’s a
>>>> lack of knowledge that we keep in secret.
>>>> 
>>>> It's time to document Durable Memory and its Native Persistence tuning
>>>> parameters. Let's start doing this for Linux based deployments first.
>> Here
>>>> is what we have for now (which is almost nothing):
>>>> https://apacheignite.readme.io/docs/durable-memory-tuning <
>>>> https://apacheignite.readme.io/docs/durable-memory-tuning>
>>>> 
>>>> Ideally, at some point we have to come up with doc like this:
>>>> https://access.redhat.com/sites/default/files/attachments/
>>>> deploying-oracle-12c-on-rhel6_1.2_1.pdf
>>>> 
>>>> Please share your expertise in a form of settings that have to be put on
>>>> the paper. We put them in JIRA and document afterwords:
>>>> https://issues.apache.org/jira/browse/IGNITE-6246 <
>>>> https://issues.apache.org/jira/browse/IGNITE-6246>
>>>> 
>>>> —
>>>> Denis
>>>> 
>>> 
>>> 
>> 


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