i am testing out jboss eap 7.1 using adoptopenjdk 8 with openj9 (previously was using hotspot). i used visualvm to monitor it via jmx, and noticed that the reported cpu usage is consistently close to 100% (see attachment). when i used htop on the host, i found that the cpu usage is nowhere that figure. after switching back to hotspot, the reported cpu usage accurately reflects whatever was reported with htop again. however, if i use jconsole + openj9, the reported cpu usage is accurate as well.
does anyone know whether this inaccuracy is commonplace for openj9 + visualvm monitoring? thanks!
I managed to reproduce this with a trivial application (that just prints the time once a second). It appears something is broken in OpenJ9: I created an issue to track fixing it.