The RHEL 7 Tomcat package uses systemd and the journal to capture stdout instead of catalina.out. Did you check the journal to see if the thread dumps are logged there from your invocations of kill -3? You can use `journalctl -u tomcat` to check it.
On Wed, Jul 1, 2020 at 6:58 PM Sean Neeley <sean.nee...@producepro.com> wrote: > On Wed, Jul 1, 2020 at 5:24 PM calder <calder....@gmail.com> wrote: > > > On Wed, Jul 1, 2020, 15:32 Sean Neeley <sean.nee...@producepro.com> > wrote: > > > > > I tried switching from Java 1.8 to Java 11 to see if that makes a > > > difference. Now the VM Thread is using a lot less CPU: > > > > > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ > > COMMAND > > > 2320 tomcat 20 0 4659072 47872 19904 R 99.9 0.6 22:15.16 java > > > 2326 tomcat 20 0 4659072 47872 19904 R 4.6 0.6 0:56.43 VM > > > Thread > > > > > > I tried running jstack on the processes, but I get this: > > > > > > 2320: Unable to open socket file: target process not responding or > > HotSpot > > > VM not loaded > > > > > > > Did you attempt to run the command as the "Tomcat user"? > > > > BTW, Oracle recommends the use of "jcmd" over "jstack". Personally, I'd > > give Mission Control/Flight Recorder a go. > > > > I'm definitely running it as the tomcat user. I just tried jcmd with no > arguments and the command completely hangs. The only way to terminate it > is a kill -9. This seems almost like an OS level issue. We are opening a > ticket with Red Hat support to see what they say. >