[SOLR-16605] CPU in UI cloud->nodes is always 0%, even when Solr is very busy.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 9.1
• Fix Version/s: 9.2
• Component/s: Admin UI
• Assignee: Shawn Heisey
• Reporter: Shawn Heisey
• Created: 02/Jan/23 19:41
• Updated: 01/Apr/23 00:16
• Resolved: 01/Apr/23 00:16

Description

The Cloud->Nodes section of the admin UI is always reporting 0% CPU even on very busy Solr nodes. I thought the attached patch would fix t, but it doesn't seem to be working. Instead of always 0%, it now shows an occasional 50% or 100%... and even rarer is a different percentage like 84% or 17%. The Solr process at that time was usng about 180% CPU (two CPUs in AWS instance).

Using OperatingSystemMXBean from com.sun instead of java.lang seemed to work fine in a quick test program, but it's not working in Solr. I am trying this on Ubuntu Linux with OpenJDK 17 and 11.