Coty -- There is a normal period of high CPU right after startup, but that's expected. However, it usually peaks well after startup (minutes or hours) and then it stays that way, sometimes all night. When it happens, all the tomcats (about 20 of them) running show high CPU, like 20-50% each.
I can write a script to loop and output top and thread dumps. Should I do it for all running instances or just for a selected target instance? --Eric -----Original Message----- From: Coty Sutherland <csuth...@apache.org> Sent: Thursday, August 8, 2019 1:22 PM To: Tomcat Users List <users@tomcat.apache.org> Subject: Re: Tomcat Server Using 100% CPU I'd suggest writing a small script to loop about 10 times and capture top and thread dumps with jstack at the same time, then wait a few seconds then repeat. After that you can grab the pid/tid from the top output and compare that with your thread dump to see exactly what the thread is doing for the iteration/duration you specify. Other questions that I haven't seen asked, how long does the CPU usage persist? Is it only at startup or does it randomly start after some uptime? Have your webapps or dependencies changed around the time the issue started? Do the working and nonworking servers run the same webapps with the same workload? On Thu, Aug 8, 2019 at 2:09 PM Eric Robinson <eric.robin...@psmnv.com> wrote: > Utkarsh and John, thank you for your feedback. > > Since everything was originally on Windows, and we built a new Linux > server with fresh tomcat installs, and the only thing we moved over > from the old Windows servers was the tomcat application folder itself, > and the 100% CPU problem persisted, I can't imagine what else could be > causing it except the tomcats, but I'm open to ideas. > > When it happens, all the tomcats start using high CPU at the same time. > See the following top output. > > top - 11:06:44 up 1 day, 6:59, 7 users, load average: 36.85, 32.67, > 34.89 > Tasks: 245 total, 4 running, 241 sleeping, 0 stopped, 0 zombie > %Cpu(s): 80.7 us, 13.5 sy, 0.0 ni, 0.0 id, 0.0 wa, 0.0 hi, 5.7 > si, > 0.0 st > KiB Mem : 48132572 total, 11677420 free, 5572688 used, 30882464 buff/cache > KiB Swap: 15626236 total, 15584324 free, 41912 used. 41859232 avail Mem > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 19379 site211 20 0 3529072 447444 24632 S 120.4 0.9 3:37.19 java > 20092 site555 20 0 2530376 375500 24496 S 72.4 0.8 2:01.44 java > 21077 site450 20 0 2530292 298260 24292 S 69.6 0.6 1:10.92 java > 20378 site436 20 0 3262200 347160 24096 S 68.3 0.7 2:47.26 java > 19957 site522 20 0 2596856 373532 24364 S 52.0 0.8 2:37.13 java > 19537 site396 20 0 2862724 386860 23820 S 51.1 0.8 2:34.25 java > 19228 site116 20 0 3595652 490032 24640 S 50.5 1.0 5:03.28 java > 20941 site456 20 0 2596996 338740 24488 S 49.2 0.7 1:32.89 java > 20789 site354 20 0 2596920 327612 24480 S 42.9 0.7 1:30.47 java > 20657 site327 20 0 3123004 346308 24540 S 41.4 0.7 1:50.97 java > 20524 site203 20 0 2458376 340400 25416 S 39.8 0.7 1:48.01 java > 19675 site487 20 0 2530296 390948 24408 S 35.7 0.8 2:37.95 java > 20233 site535 20 0 2530292 324112 24360 S 32.9 0.7 1:54.31 java > 19809 site514 20 0 2530216 400308 24340 S 25.7 0.8 2:35.97 java > 44 root 20 0 0 0 0 R 19.1 0.0 159:46.15 > ksoftirqd/7 > 3926 root 20 0 208512 22668 4128 S 16.9 0.0 242:45.07 iotop > 2036 root 20 0 0 0 0 R 13.2 0.0 1:38.31 > kworker/7:0 > > I'll check the localhost_access logs and see if something suspicious > stands out. > > --Eric > > > -----Original Message----- > From: Utkarsh Dave <utkarshkd...@gmail.com> > Sent: Thursday, August 8, 2019 12:33 PM > To: Tomcat Users List <users@tomcat.apache.org> > Subject: Re: Tomcat Server Using 100% CPU > > Did you reviewed the localhost_access log file. Which web-application > is using tomcat the most ? > > On Thu, Aug 8, 2019 at 9:53 AM Eric Robinson <eric.robin...@psmnv.com> > wrote: > > > We have a farm of VMs, each running multiple instances of tomcat (up > > to 80 instances per server). Everything has been running fine for > > years, but recently one server has started nailing the CPU to 100% > utilization. > > > > We have tried: > > > > > > * Different versions of tomcat and JDK > > * Doubling the resources to 16 cores and 56 GB RAM > > * Moving the VM to different physical server > > * Rebuilding the tomcat instances on a brand new VM using Windows > > Server 2019 > > * Rebuilding the tomcat instances on a brand new VM using Red Hat > > Enterprise Linux 7.5 > > > > Nothing has worked. No matter where we run the tomcats, they drive > > CPU up to 100%. Meanwhile the other six servers are still running fine. > > They all run the same canned tomcat applications. > > > > We would appreciate some guidance on getting to the bottom of this > problem. > > > > --Eric > > > > > > Disclaimer : This email and any files transmitted with it are > > confidential and intended solely for intended recipients. If you are > > not the named addressee you should not disseminate, distribute, copy > > or > alter this email. > > Any views or opinions presented in this email are solely those of > > the author and might not represent those of Physician Select Management. > > Warning: Although Physician Select Management has taken reasonable > > precautions to ensure no viruses are present in this email, the > > company cannot accept responsibility for any loss or damage arising > > from the use of this email or attachments. > > > Disclaimer : This email and any files transmitted with it are > confidential and intended solely for intended recipients. 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