I would expect at least 1 IndexSearcher per replica, how many total replicas hosted in your JVM?
Plus, if you're actively indexing, there may temporarily be 2 IndexSearchers open while the new searcher warms. And there may be quite a few caches, at least queryResultCache and filterCache and documentCache, one of each per replica and maybe two (for queryResultCache and filterCache) if you have a background searcher autowarming. At a glance, your autowarm counts are very high, so it may take some time to autowarm leading to multiple IndexSearchers and caches open per replica when you happen to hit a commit point. I usually start with 16-20 as an autowarm count, the benefit decreases rapidly as you increase the count. I'm not quite sure why it would be different in 7x .vs. 6x. How much heap do you allocate to the JVM? And do you see similar heap dumps in 6.6? Best, Erick On Mon, Sep 3, 2018 at 10:33 AM Björn Häuser <bjoernhaeu...@gmail.com> wrote: > > Hello, > > we recently upgraded our solrcloud (5 nodes, 25 collections, 1 shard each, 4 > replicas each) from 6.6.0 to 7.3.0 and shortly after to 7.4.0. We are running > Zookeeper 4.1.13. > > Since the upgrade to 7.3.0 and also 7.4.0 we encountering heap space > exhaustion. After obtaining a heap dump it looks like that we have a lot of > IndexSearchers open for our largest collection. > > The dump contains around ~60 IndexSearchers, and each containing around ~40mb > heap. Another 500MB of heap is the fieldcache, which is expected in my > opinion. > > The current config can be found here: > https://gist.github.com/bjoernhaeuser/327a65291ac9793e744b87f0a561e844 > <https://gist.github.com/bjoernhaeuser/327a65291ac9793e744b87f0a561e844> > > Analyzing the heap dump eclipse MAT says this: > > Problem Suspect 1 > > 91 instances of "org.apache.solr.search.SolrIndexSearcher", loaded by > "org.eclipse.jetty.webapp.WebAppClassLoader @ 0x6807d1048" occupy > 1.981.148.336 (38,26%) bytes. > > Biggest instances: > > • org.apache.solr.search.SolrIndexSearcher @ 0x6ffd47ea8 - 70.087.272 > (1,35%) bytes. > • org.apache.solr.search.SolrIndexSearcher @ 0x79ea9c040 - 65.678.264 > (1,27%) bytes. > • org.apache.solr.search.SolrIndexSearcher @ 0x6855ad680 - 63.050.600 > (1,22%) bytes. > > > Problem Suspect 2 > > 223 instances of "org.apache.solr.util.ConcurrentLRUCache", loaded by > "org.eclipse.jetty.webapp.WebAppClassLoader @ 0x6807d1048" occupy > 1.373.110.208 (26,52%) bytes. > > > Any help is appreciated. Thank you very much! > Björn
