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 <nivano...@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.glu...@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 > >> > > > > >
