You're right, segment merges can be catastrophic to ongoing searches. I explored the problem here: http://blog.mikemccandless.com/2010/06/lucene-and-fadvisemadvise.html but a lot has changed since then...
SEQUENTIAL is probably best (if the OS implements it; I think the Linux kernel has improved here), because then the OS knows to read ahead and aggressively free the page once we are done using it. There is also O_DIRECT (e.g., using NativeUnixDirectory) for direct IO to bypass the buffer cache entirely. Mike McCandless http://blog.mikemccandless.com On Wed, May 21, 2014 at 4:09 AM, Ravikumar Govindarajan <ravikumar.govindara...@gmail.com> wrote: > Is it a good idea to use FADVISE_DONTNEED/MADVISE_DONTNEED flags during > segment merge reads? > > Buffer-Cache contains critical data belonging to searches. A segment-merge > has the potential to disturb the cache no? > > -- > Ravi --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
