Faceting and sorting are the two biggest places people get into trouble. You've been asking questions about Solr Cloud, so I assume you're working on a trunk release. Note that most everything people know about memory consumption painfully gained over the years is...wrong on trunk.
Or at least may be wrong. Just for yucks I took an 11M document Wiki dump and indexed it as just a few (10 or so) fields. Then I faceted (as I remember) on the text field (a seriously bad thing to do). Memory consumption dropped 70+%. Restated: I was using less than 1/3 of the memory. Additionally, as I understand it the memory allocation is very significantly different for strings and things. There should be many, many fewer objects created when searching in Solr and the garbage collection should be lots less intensive. Now, I wasn't involved in writing the code, so my understanding may be way off base. I've also seen problems with garbage collection kicking in and not doing much, but I expect trunk alters that problem for the above reasons as well. But yes, jConsole or similar is about the only way to measure this. If you haven't read Mark Miller's excellent article on GC, you might want to: http://www.lucidimagination.com/blog/2011/03/27/garbage-collection-bootcamp-1-0/ The caches are where the memory consumption really shows up, BTW, see: http://wiki.apache.org/solr/SolrCaching The queryResultCache and documentCache are generally not where problems show up, but watching the stats on the other caches to see if you're getting decent hit ratios can be a pointer too. And if you're stressing things with trunk I'll be very interested in your results! Erick On Mon, Mar 19, 2012 at 3:15 PM, Jamie Johnson <jej2...@gmail.com> wrote: > I am not currently running into memory issues, but I was wondering if > anyone could explain to me Solrs memory usage? What does Solr > actually store in memory? What are some of the largest memory > consumers (i.e. faceting, sorting, etc). Is the best way to start > addressing questions like this to just fire up JConsole?
