Added Ignite Persistence related section to the “Performance Tips” docs and mentioned this suggestion there: https://apacheignite.readme.io/docs/performance-tips#tune-ignite-native-persistence
— Denis > On Aug 17, 2017, at 6:18 PM, Dmitriy Setrakyan <dsetrak...@apache.org> wrote: > > On Tue, Aug 15, 2017 at 10:09 PM, Serge Puchnin <sergey.puch...@gmail.com> > wrote: > >> #1 option looks more predictable. But it's possible to add a message "for >> better IO performance please migrate to 4K-pages". >> > > Agree. Can we update the ticket to make sure that this suggestion is > printed out? > > >> BR, >> Serge >> >> >> On Wed, 16 Aug 2017 at 03:46, Dmitriy Setrakyan <dsetrak...@apache.org> >> wrote: >> >>> I like #1 if possible. Of course, if the LFS is empty, then the new >> default >>> should be 4k. >>> >>> On Tue, Aug 15, 2017 at 12:01 PM, Ivan Rakov <ivan.glu...@gmail.com> >>> wrote: >>> >>>> Guys, >>>> >>>> We have benchmarked how checkpoint write speed on SSD disk depends on >>>> various parameters. It became absolutely obvious that using 4K pages in >>>> durable memory instead of 2K brings considerable, significant >> speed-up. I >>>> think, we must set 4K as default page size. >>>> Ticket with detailed explanation: https://issues.apache.org/jira >>>> /browse/IGNITE-5884 >>>> Spoiler: it depends on write order and alignment, but writing 4K is at >>>> least *3x faster* than writing 2K when other parameters are the same. >>>> >>>> The question is backwards compatibility. If pageSize is not explicitly >>> set >>>> in user configuration, attempt to start "4k default" Ignite node from >> "2k >>>> default" LFS files will fail with exception: >>>> >>>> class org.apache.ignite.IgniteCheckedException: Failed to verify store >>>>> file (invalid page size) [expectedPageSize=4096, filePageSize=2048] >>>>> at org.apache.ignite.internal.processors.cache.persistence.file >>>>> .FilePageStore.checkFile(FilePageStore.java:206) >>>>> at org.apache.ignite.internal.processors.cache.persistence.file >>>>> .FilePageStore.init(FilePageStore.java:416) >>>>> at org.apache.ignite.internal.processors.cache.persistence.file >>>>> .FilePageStore.read(FilePageStore.java:315) >>>>> at org.apache.ignite.internal.processors.cache.persistence.file >>>>> .FilePageStoreManager.read(FilePageStoreManager.java:287) >>>>> at org.apache.ignite.internal.processors.cache.persistence.file >>>>> .FilePageStoreManager.read(FilePageStoreManager.java:272) >>>>> at org.apache.ignite.internal.processors.cache.persistence.page >>>>> mem.PageMemoryImpl.acquirePage(PageMemoryImpl.java:569) >>>>> at org.apache.ignite.internal.processors.cache.persistence.page >>>>> mem.PageMemoryImpl.acquirePage(PageMemoryImpl.java:487) >>>>> at org.apache.ignite.internal.processors.cache.persistence.Grid >>>>> CacheOffheapManager.getOrAllocateCacheMetas(GridCacheOffheap >>>>> Manager.java:515) >>>>> at org.apache.ignite.internal.processors.cache.persistence.Grid >>>>> CacheOffheapManager.initDataStructures(GridCacheOffheapManager.java: >> 86) >>>>> at org.apache.ignite.internal.processors.cache.IgniteCacheOffhe >>>>> apManagerImpl.start(IgniteCacheOffheapManagerImpl.java:139) >>>>> at org.apache.ignite.internal.processors.cache.CacheGroupContex >>>>> t.start(CacheGroupContext.java:868) >>>>> >>>> >>>> I think, we have two options here: >>>> >>>> 1) Obvious and safe - provide silent backwards compatibility. We can >>>> implement a task which will find any LFS file, check its pageSize and >> use >>>> it as default. >>>> 2) Less user-friendly, but in my opinion still better option - crash >>> node, >>>> but make error message more informative. We'll let user know that >> default >>>> pageSize was changed to 4k due to discovered performance boost on most >>>> UNIX-based enviroments with SSD (which is for sure most popular >>> enviroment >>>> among users), and recommend user to migrate to 4K-page LFS. If user >> still >>>> wants to work with 2k pages, he can always set it explicitly in >>>> MemoryConfiguration and start node. >>>> >>>> Thoughts? >>>> >>>> -- >>>> Best Regards, >>>> Ivan Rakov >>>> >>>> >>> >>
