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 <[email protected]> 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 [email protected]. > 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/CAPmjWd2aPWDzg9PZcHpQyKbFiK_p-385NR7z8PNsnpdmu%3D_f4Q%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
