Dmitriy, First of all, thanks for putting this low level details on paper! Current and future community members will be grateful to you.
Second, let me be a reviewer of the page and suggest some improvements. Until the review is over I would encourage us to hold on with any public announcements such as blog post. I’ve reviewed and edited Ignite Durable Memory section (https://cwiki.apache.org/confluence/display/IGNITE/Ignite+Durable+Memory+-+under+the+hood#IgniteDurableMemory-underthehood-IgniteDurableMemory <https://cwiki.apache.org/confluence/display/IGNITE/Ignite+Durable+Memory+-+under+the+hood#IgniteDurableMemory-underthehood-IgniteDurableMemory>). Please address the questions below and I’ll move on with the new sections afterwards. 1) "Different caches and its partitions bring more complex addressing scheme but it is still possible to map from page ID to position in particular file: pageId => file + offset in this file”. Probably this appears too early in the doc because above we just introduced page ID notion with durable memory and now we’re talking about some files? Are these files of ignite persistence? What if the persistence is disabled? Honestly, the sentence gets out of the story context. 2) "Also, the tree pages can be merged into one if < 50% of space is used.” 50% of the whole memory available? Please clarify. 3) "There is one page ID table per memory segment.” It’s the same segment as it’s described in the main doc, right? https://apacheignite.readme.io/docs/memory-architecture#section-memory-segment <https://apacheignite.readme.io/docs/memory-architecture#section-memory-segment> 4) "within unsafe segment” If we want to mention “usafe” here we need to explain what that is. 5) "If memory amount less than whole index size, Ignite still can operate.” How do we define “index size”? Is this the page size? — Denis > On Aug 30, 2017, at 8:24 AM, Dmitry Pavlov <dpavlov....@gmail.com> wrote: > > Hi Igniters, > > > I am glad to introduce two new wiki articles. These articles contain > high-level description of > > - Ignite Durable Memory ( > https://cwiki.apache.org/confluence/display/IGNITE/Ignite+Durable+Memory+-+under+the+hood > ) > > - and Ignite Persistent Store ( > https://cwiki.apache.org/confluence/display/IGNITE/Ignite+Persistent+Store+-+under+the+hood > ) > > These articles cover basic principles and internal design. Pages may be > useful for new contributors during start of working with persistent store > code base. > > > I would like to thank all contributors who helped me with my questions. > Their answers and support made it possible to start this description. > > > I will appreciate any feedback and questions. Suggestions and edits are > welcome, of course. > > > Sincerely, > > Dmitriy Pavlov
