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
I tried running strace on the process and see this over and over in the
output:
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, <unfinished ...>
[pid 2334] <... futex resumed>) = -1 ETIMEDOUT (Connection timed
out)
[pid 2334] futex(0x3fff7c1fd228, FUTEX_WAKE_PRIVATE, 1) = 0
[pid 2334] futex(0x3fff7c1fd254, FUTEX_WAIT_BITSET_PRIVATE, 17307,
{tv_sec=2074, tv_nsec=141673818}, 0xffffffff <unfinished ...>
[pid 2326] <... nanosleep resumed>NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
[pid 2326] nanosleep({tv_sec=0, tv_nsec=1000000}, NULL) = 0
/var/log/tomcat logs are still empty. I'm running out of ideas.
Sean
On Wed, Jul 1, 2020 at 12:55 PM <john.e.gr...@wellsfargo.com.invalid> wrote:
> Sean,
>
>
> > -----Original Message-----
> > From: Sean Neeley <sean.nee...@producepro.com>
> > Sent: Wednesday, July 01, 2020 12:26 PM
> > To: Tomcat Users List <users@tomcat.apache.org>
> > Subject: Re: Having trouble with tomcat 7 installation on RHEL 7.8 power
> pc
> >
> > John, The top two processes are:
> >
> > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+
> COMMAND
> > 19360 tomcat 20 0 3302144 42560 18944 R 99.9 0.5 46:02.37 java
> > 19363 tomcat 20 0 3302144 42560 18944 R 98.4 0.5 45:48.50 VM
> Thread
> >
> > I tried kill -3 on both of them, plus the java process ID I see from a
> "ps"
> > command, several seconds apart. The only logs created are these, and
> they
> > are still all empty after the kill -3:
> > -rw-r--r-- 1 tomcat tomcat 0 Jul 1 10:22 catalina.2020-07-01.log
> > -rw-r--r-- 1 tomcat tomcat 0 Jul 1 10:22
> host-manager.2020-07-01.log
> > -rw-r--r-- 1 tomcat tomcat 0 Jul 1 10:22 localhost.2020-07-01.log
> > -rw-r--r-- 1 tomcat tomcat 0 Jul 1 10:22 manager.2020-07-01.log
> >
> > Any other ideas?
> >
> > On Wed, Jul 1, 2020 at 12:09 PM <john.e.gr...@wellsfargo.com.invalid>
> > wrote:
> >
> > > Sean,
> > >
> > > > -----Original Message-----
> > > > From: Sean Neeley <sean.nee...@producepro.com>
> > > > Sent: Wednesday, July 01, 2020 11:15 AM
> > > > To: users@tomcat.apache.org
> > > > Subject: Having trouble with tomcat 7 installation on RHEL 7.8 power
> > > > pc
> > > >
> > > > I just installed tomcat 7 on a Red Hat Enterprise Linux Server 7.8,
> > > power pc
> > > > system. As soon as the service starts, the java process uses 100%
> cpu.
> > > > Logs get created in /var/log/tomcat, but they all have size 0 bytes.
> > > > I
> > > have not
> > > > modified the standard configuration (tomcat.conf, server.xml, etc).
> > > > The tomcat packages that are installed are:
> > > >
> > > > tomcat-7.0.76-12.el7_8.noarch
> > > > tomcat-jsp-2.2-api-7.0.76-12.el7_8.noarch
> > > > tomcat-el-2.2-api-7.0.76-12.el7_8.noarch
> > > > tomcat-lib-7.0.76-12.el7_8.noarch
> > > > tomcat-servlet-3.0-api-7.0.76-12.el7_8.noarch
> > > >
> > > > Are there any tricks I can use to troubleshoot what is going wrong?
> > > > Without any logs being created, it seems impossible to determine the
> > > > problem. Thanks for helping.
> > > >
> > > > Sean
> > >
> > > Use kill -3 to take several thread dumps about 5-10 seconds apart.
> > > They will probably end up in catalina.out.
> > >
> > > You can also use top -H to see what individual threads are using CPU.
> > >
> > >
>
> Sorry, I don't know much more.
>
> It's interesting that the CPU is being consumed by "VM Thread." It
> doesn't look like an ordinary Tomcat or application problem. When I
> googled "java vm thread," I got some interesting results, such as this one:
>
>
> https://docs.oracle.com/javase/7/docs/webnotes/tsg/TSG-VM/html/hangloop.html
>
> That also describes the scenario where a thread dump doesn't seem to do
> anything.
>
>
>
