On 12/2/2016 12:01 PM, S G wrote: > This post shows some stats on Solr which indicate that there might be a > memory leak in there. > > http://stackoverflow.com/questions/40939166/is-this-a-memory-leak-in-solr > > Can someone please help to debug this? > It might be a very good step in making Solr stable if we can fix this.
+1 to what Walter said. I replied earlier on the stackoverflow question. FYI -- your 95th percentile request time of about 16 milliseconds is NOT something that I would characterize as "very high." I would *love* to have statistics that good. Even your 99th percentile request time is not much more than a full second. If a search takes a couple of seconds, most users will not really care, and some might not even notice. It's when a large percentage of queries start taking several seconds that complaints start coming in. On your system, 99 percent of your queries are completing in 1.3 seconds or less, and 95 percent of them are less than 17 milliseconds. That sounds quite good to me. In my experience, the time it takes for the browser to receive the search result page and render it is a significant part of the total time to see results, and often dwarfs the time spent getting info from Solr. Here's some numbers from Solr in my organization: requests: 4102054 errors: 364894 timeouts: 49 totalTime: 799446287.45041 avgRequestsPerSecond: 1.2375565828793849 5minRateReqsPerSecond: 0.8444329508327961 15minRateReqsPerSecond: 0.8631197328073346 avgTimePerRequest: 194.88926460997587 medianRequestTime: 20.8566605 75thPcRequestTime: 85.51328849999999 95thPcRequestTime: 2202.277466549999 99thPcRequestTime: 5280.375381280002 999thPcRequestTime: 6866.020122961001 The numbers above come from a distributed index that contains 167 million documents and takes up about 200GB of disk space across two machines. requests: 192683 errors: 124 timeouts: 0 totalTime: 199380421.985073 avgRequestsPerSecond 0.042222722771354554 5minRateReqsPerSecon 0.00800545427600684 15minRateReqsPerSecond: 0.017521222412364163 avgTimePerRequest: 1034.7587591280653 medianRequestTime: 541.591858 75thPcRequestTime: 1683.83246125 95thPcRequestTime: 5644.542019949997 99thPcRequestTime: 9445.592394760004 999thPcRequestTime: 14602.166640771007 These numbers are from an index with about 394 million documents, taking up nearly 500GB of disk space. This index is also distributed on multiple machines. Are you experiencing any problems other than what you perceive as slow queries? I asked some other questions on stackoverflow. In particular, I'd like to know the total memory on the server, the total number of documents (maxDoc and numDoc) you're handling with this server, as well as the total index size. What do your queries look like? What version and vendor of Java are you using? Can you share your config/schema? A memory leak is very unlikely, unless your Java or your operating system is broken. I can't say for sure that it's not happening, but it's just not something we see around here. Here's what I have collected on performance issues in Solr. This page does mostly concern itself with memory, though it touches briefly on other topics: https://wiki.apache.org/solr/SolrPerformanceProblems Thanks, Shawn
