Indeed the behaviour is the same on Windows and Linux: memory that is not used by processes is used by the operating system in order to cache the hottest parts of the file system. The reason why the docs say that the rest should be left to Lucene is that most disk accesses that elasticsearch performs are done through Lucene.
On Wed, Nov 26, 2014 at 8:44 PM, Nikolas Everett <nik9...@gmail.com> wrote: > I imagine all operating systems have some kind of disk caching. I just > happen to be used to linux. > > > On Wed, Nov 26, 2014 at 2:42 PM, BradVido <bradyvido...@gmail.com> wrote: > >> I see, but I'm running on Windows. Is the behavior similar, or does this >> not exist on Windows? >> >> On Wednesday, November 26, 2014 1:01:02 PM UTC-6, Nikolas Everett wrote: >>> >>> Lucene runs in the same JVM as Elasticsearch but (by default) it mmaps >>> files and then iterates over their content inteligently. That means most >>> of its actual storage is "off heap" (its a java buzz-phrase). Anyway, >>> Linux will serve reads from mmaped files from its page cache. That is why >>> you want to leave linux a whole bunch of unused memory. >>> >>> Nik >>> >>> On Wed, Nov 26, 2014 at 1:53 PM, BradVido <bradyv...@gmail.com> wrote: >>> >>>> I've read the recommendations for ES_HEAP_SIZE >>>> <http://www.elasticsearch.org/guide/en/elasticsearch/guide/current/heap-sizing.html> >>>> which >>>> basically state to set -Xms and -Xmx to 50% physical RAM. >>>> It says the rest should be left for Lucene to use (OS filesystem >>>> caching). >>>> But I'm confused on how Lucene uses that. Doesn't Lucene run in the >>>> same JVM as ES? So they would share the same max heap setting of 50%. >>>> >>>> Can someone clear this up? >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "elasticsearch" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to elasticsearc...@googlegroups.com. >>>> To view this discussion on the web visit https://groups.google.com/d/ >>>> msgid/elasticsearch/4c0b4045-74d4-400a-b636-e150a1261be4% >>>> 40googlegroups.com >>>> <https://groups.google.com/d/msgid/elasticsearch/4c0b4045-74d4-400a-b636-e150a1261be4%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "elasticsearch" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to elasticsearch+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/elasticsearch/b7c67641-6a83-428c-91d2-10bbb6d17f0f%40googlegroups.com >> <https://groups.google.com/d/msgid/elasticsearch/b7c67641-6a83-428c-91d2-10bbb6d17f0f%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> >> For more options, visit https://groups.google.com/d/optout. >> > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to elasticsearch+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elasticsearch/CAPmjWd3g0g7gv79a6DchCCjrbhD_Ek3tfAkuPA08Q1GYbdH2Rg%40mail.gmail.com > <https://groups.google.com/d/msgid/elasticsearch/CAPmjWd3g0g7gv79a6DchCCjrbhD_Ek3tfAkuPA08Q1GYbdH2Rg%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- Adrien Grand -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to elasticsearch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/CAL6Z4j54pntydsUmd%3DAHcz0aRSd8YuD70XhukCwcghkFeG2ugA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
