Hi Sophie, Thanks for the KIP write-up, I made a pass over the wiki and the PR as well, here's some comments:
1. the proposed API seems to be inconsistent from the PR, should it be: public static WindowBytesStoreSupplier inMemoryWindowStore(final String name, final Duration retentionPeriod, final Duration windowSize, + final boolean retainDuplicates) throws IllegalArgumentException ... - final Duration gracePeriod 2. As Boyang mentioned, we usually do not need to elaborate on the internal implementation in the KIP, unless it has some user-facing implications. As for this specific KIP, I think it make more sense to talk about what memory footprint users would expect to have with the implementation: should they be expecting exact number of bytes used for key-value pairs only, or should they expect some additional memory used for maintaining the window data structures. Guozhang On Fri, Feb 8, 2019 at 4:21 AM Dongjin Lee <dong...@apache.org> wrote: > Thanks for the KIP, Sophie. I added your KIP into the 'Under Discussion' > section here > < > https://cwiki.apache.org/confluence/display/KAFKA/Kafka+Improvement+Proposals > > > . > > I am +1 for this proposal for reaching parity between key-value store and > windowed store. > > Thanks, > Dongjin > > On Fri, Feb 8, 2019 at 1:41 PM Boyang Chen <bche...@outlook.com> wrote: > > > Thanks Sophie for proposing this new feature! In-memory window store is > > very useful in long term. One meta comment is that we don't need to > include > > implementation details in the public interface section, and those > > validation steps are pretty trivial. > > > > Boyang > > > > ________________________________ > > From: Sophie Blee-Goldman <sop...@confluent.io> > > Sent: Friday, February 8, 2019 9:56 AM > > To: dev@kafka.apache.org > > Subject: [DISCUSS] KIP-428: Add in-memory window store > > > > Streams currently only has support for a RocksDB window store, but users > > have been requesting an in-memory version. This KIP introduces a design > for > > an in-memory window store implementation. > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-428%3A+Add+in-memory+window+store > > > > > -- > *Dongjin Lee* > > *A hitchhiker in the mathematical world.* > *github: <http://goog_969573159/>github.com/dongjinleekr > <https://github.com/dongjinleekr>linkedin: kr.linkedin.com/in/dongjinleekr > <https://kr.linkedin.com/in/dongjinleekr>speakerdeck: > speakerdeck.com/dongjin > <https://speakerdeck.com/dongjin>* > -- -- Guozhang