I migrated an application from Solr 4 to Solr 6. solrconfig.xml and schema.xml are sensibly the same. The JVM params are also pretty much similar. The indicces have each about 2 million documents. No particular tuning was done to Solr 6 beyond the default settings. Solr 4 is running in Tomcat 7.
Early results seem to show Solr 4 outperforming Solr 6. The first shows an average response time of 280 ms while the second averages at 430 ms. The test cases were exactly the same, the machines where exactly the same and heap settings exactly the same (Xms24g, Xmx24g). Requests were sent with Jmeter with 50 concurrent threads for 2h. I know that this is not enough information to claim that Solr 4 generally outperforms Solr 6. I also know that this pretty much depends on what the application does. So I am not claiming anything general. All I want to do is get some input before I start digging. What are some things I could tune to improve the numbers for Solr 6? Have you guys experienced such discrepancies? Thanks, Max.
