[xwiki-users] Performance Frustrations

Hi We were chugging along quite happily with XWiki then we started to notice a slowdown. Simple pages (like the space webhome page) were taking 3 – 4 seconds to load. This is with only 1 user testing it and about 5 articles in the whole system. Using htop, we can see that the tomcat process are being created and the CPU is going to over 150% - 400% (total across several cores). I have tried modifying the JAVA_OPTS in /etc/default/tomcat7 with little to no effect what so ever. I have tried googling it and almost everyone says to change those options and I’ve tried basing it on the recommendation in http://platform.xwiki.org/xwiki/bin/view/AdminGuide/Performances#HMemory and my current line reads: JAVA_OPTS="-Djava.awt.headless=true -Xmx800m -XX:MaxPermSize=196m -XX:+UseConcMarkSweepGC" We are running XWiki 6.4.2 xwiki-enterprise-tomcat7-mysql package installed using apt-get. OS: Ubuntu 14.04.2 LTS (GNU/Linux 3.13.0-46-generic x86_64) RAM: 4096 vCPU: 12 Hypervisor: Hyper-v There aren’t any IO or memory issues that we can see. I don’t see any immediate errors in the logs either. To be honest the high CPU isn’t that much of an issue. The problem is that it’s using high CPU and STILL has slow performance. If I compare the response of loading a 75 line article to loading http://extensions.xwiki.org/xwiki/bin/view/ExtensionCode/ExtensionSearch?sp…hild, the extension page loads about 3 times faster (not scientifically accurate timing but it’s different enough to notice consistently). Any help would be greatly appreciated because no matter how great XWiki is, if I can’t get it to perform quickly enough, users will avoid using it. Thanks again for your time and any help. Kind regards, Mahomed