On 3/24/2016 4:02 AM, Robert Brown wrote: > If my index data directory size is 70G, and I don't have 70G (plus > heap, etc) in the system, this will occasionally affect search speed > right? When Solr has to resort to reading from disk? > > Before I go out and throw more RAM into the system, in the above > example, what would you recommend?
Having enough memory available to cache all your index data offers the best possible performance. You may be able to achieve acceptable performance when you don't have that much memory, but I would try to make sure there's at least enough memory available to cache *half* the index data. Depending on the nature of your queries and your index, this might not be enough, but chances are good that it would work well. I have a dev server where there's only enough memory available to cache about a tenth of the index -- it's got full copies of all three of my large indexes on ONE machine, while production runs two copies of these same indexes on ten machines. Performance of any single query is not very good on the dev server, but if I absolutely had to use that server for production with one of my indexes, it would be a slow, but I could do it. I don't think it would have enough performance to handle running all three indexes for production, though. Thanks, Shawn
