Hello, We have migrated from Solr 5.4.1 to Solr 6.4.0 on Amazon EC2 and we have a high CPU SYS usage and it drastically decreases the Solr performance.
The JVM version (java-1.8.0-openjdk-1.8.0.131-0.b11.el6_9.x86_64), the Jetty version (9.3.14) and the OS version (CentOS 6.9) have not changed with the Solr upgrade. Using "strace" command we have found a lot of "clock_gettime" (gettimeofday) calls when Solr is started. The clocksource on Amazon VMs is "xen" and, according to this web site, it impacts the system calls: https://blog.packagecloud.io/eng/2017/03/08/system-calls-are-much-slower-on-ec2/ We have updated the clocksource to "tsc" and it fixes the issue. Is there a change between Solr 5.4.1 and 6.4.0 that would trigger many more gettimeofday calls done by the JVM ? Elodie Kelkoo SAS Société par Actions Simplifiée Au capital de € 4.168.964,30 Siège social : 158 Ter Rue du Temple 75003 Paris 425 093 069 RCS Paris Ce message et les pièces jointes sont confidentiels et établis à l'attention exclusive de leurs destinataires. Si vous n'êtes pas le destinataire de ce message, merci de le détruire et d'en avertir l'expéditeur.
