Guys, Thanks for responses. But I still fail to understand how it affects a user.
Are you saying that with persistence enabled Random-LRU is always used regardless of what is specified in pageEvictionMode, while in in-memory only scenario we can also utilize Random-2-LRU for eviction? Is this accurate? Are there any other differences? -Val On Thu, Feb 1, 2018 at 5:01 AM, Dmitry Pavlov <dpavlov....@gmail.com> wrote: > Hi Vyacheslav, > > Yes, this is right, but for now PDS page based eviction uses Random-LRU, > not Random-2-LRU. Something may be changed in future Ignite releases, but > now Random-LRU is used. I am going to research if there is some room for > improvements in this aspect (e.g. IGNITE-7507 recenly found). > > If clean page is evicted, nothing really happends. If dirty page is evicted > from region during checkpointing process run, page is stored in file before > eviction > > Some info about this can be found in > https://cwiki.apache.org/confluence/display/IGNITE/ > Ignite+Durable+Memory+-+under+the+hood#IgniteDurableMemory- > underthehood-Pagebasedeviction > > Sincerely, > Dmitriy Pavlov > > чт, 1 февр. 2018 г. в 9:53, Vyacheslav Daradur <daradu...@gmail.com>: > > > Hi Valentin, > > > > As far as I know, when persistence is enabled and Ignite can't > > allocate new page-memory in the memory segment, then Ignite > > automatically evict some data from RAM to PDS using Random-2-LRU > > eviction algorithm. And there are no mechanisms to evict entries out > > when PDS is enabled. > > > > I'll be glad if I am not right and someone will correct me because, as > > Ignite user, I can't use PDS only as RAM disk replication for the use > > case in my project. > > > > > > On Thu, Feb 1, 2018 at 3:53 AM, Valentin Kulichenko > > <valentin.kuliche...@gmail.com> wrote: > > > Folks, > > > > > > On "Eviction Policies" documentation page [1] we have the following > > callout: > > > > > >> Configured eviction policy has no effect if Ignite persistence is > > enabled > > >> Note that if Ignite Persistence is enabled, then the page-based > > evictions > > > have no effect because the oldest pages will be purged from memory > > > automatically. > > > > > > This really confuses me. Why is there a difference in how data is > evicted > > > from memory depending on having disk enabled or not? And how does > > eviction > > > work with persistence enabled then? > > > > > > Does anyone can clarify? > > > > > > [1] https://apacheignite.readme.io/docs/evictions > > > > > > -Val > > > > > > > > -- > > Best Regards, Vyacheslav D. > > >
