System and Process + Kernel CPU usage estimates stuck at 100

[johnmuller71]

We are running YourKit 2020.9 and remote profiling a Java application hosted inside a Linux Docker container. Checking /proc/stat and top shows that our CPU has idle time, and is usually sitting at around 60-70% usage.

We used the guide https://www.yourkit.com/docs/java/help/docker.jsp to setup our Dockerfile and have no special options enabled, everything default.

When attached to the remote agent, it shows constant 100% CPU usage. System is at 100% and Process + Kernel is at 100% always for the entire duration of the session.



This is definitely incorrect, is there any way to fix this or improve the accuracy of the estimate?

Thanks.

[Anton Katilin]

Hello,

It's a new issue.

What processor count is shown in the "Summary" tab, in the "Operating System" section?
Does it match the actual number?

Could you please send to [email protected] the following:
- the profiler agent log file <user home>/.yjp/log/<session name>-<pid>.log
- a performance snapshot file demonstrating the problem
- "uname -a" output of the host
- "uname -a" inside the container.

[Anton Katilin]

Update:

The problem was caused by using particular OpenJDK version which incorrectly reported the processor count.

The problem was solved by using another OpenJDK version (namely, from https://hub.docker.com/r/adoptopenjdk/openjdk8).