Hi Shawn, Since my solr services power product search for a large retail web site with over fourteen million unique products, so I'm suspecting the main reason for the low hit rate is many unique user queries. We're expanding our product count and product type categories every day as fast as we can.
Thanks! Robi -----Original Message----- From: Shawn Heisey [mailto:s...@elyograg.org] Sent: Tuesday, January 29, 2013 2:24 PM To: solr-user@lucene.apache.org Subject: Re: queryResultCache *very* low hit ratio On 1/29/2013 1:36 PM, Petersen, Robert wrote: > My queryResultCache hitratio has been trending down lately and is now at > 0.01%, and also it's warmup time was almost a minute. I have lowered the > autowarm count dramatically since there are no hits anyway. I also wanted to > lower my autowarm counts across the board because I am about to expand the > warmup queries in my newSearcher config section. Would I be better just > turning off this cache completely? I don't really want to increase its size > because I've found that by keeping my cache sizes limited keeps me from > getting OOM exceptions across my slave farm. A low hit ratio on this cache means quite simply that most of your queries (q parameter) are unique. Often this is the result of including unique identifiers within the query text, or using the NOW variable in queries against a date field, because NOW changes every millisecond. By using rounding (NOW/HOUR, NOW/DAY) you can fix the latter. Sometimes it's caused by an unexpected and very very active query source. If your developers see your Solr service as an unlimited resource, they might write programs that bombard the server with unique queries. If that's what is happening, you might need another copy of your solr infrastructure that's for internal use only. Sometimes it's just because your users are entering a lot of unique searches, or not visiting multiple pages of results. If you're not seeing any value from the cache, turning it off might be sensible so it doesn't use memory. Thanks, Shawn
