Hi Robert, thank you for the response. I understand that NIOFSDirectory also uses the FS cache, but doesn't MMapDirectory tend to fill up the cache with unnecessary data for random access pattern due to sequential read-ahead? Our concern is that it can potentially lead to evicting hot pages used by another process on the same host, affecting its performance. As far as I can Elasticsearch also avoids using MMap for everything by default, e.g stored fields and term vectors are not MMAPed.
Does it make sense or am I missing something? Is my understanding correct that it still makes sense to avoid MMAPing files with the random access pattern on the most recent Lucene and JVM versions? Thank you, Alex On Fri, Aug 19, 2022 at 2:42 AM Robert Muir <rcm...@gmail.com> wrote: > On Thu, Aug 18, 2022 at 1:47 PM Alexander Lukyanchikov > <alexanderlukyanchi...@gmail.com> wrote: > > > > > Currently we are trying to avoid switching to MMAP because there is > another process running on the same host and extensively utilizes the FS > cache. > > > > This makes no sense, NIOFSDirectory uses the FS cache the exact same > way as mmap. it just uses read() interface instead. > > A self-created problem! > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org > For additional commands, e-mail: dev-h...@lucene.apache.org > >
