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 >> > >
