André, Paul, and Coty, you've all provided some great next steps. I'll investigate further and be back in touch!
--Eric -----Original Message----- From: André Warnier (tomcat) <a...@ice-sa.com> Sent: Thursday, August 8, 2019 3:53 PM To: users@tomcat.apache.org Subject: Re: Tomcat Server Using 100% CPU On 08.08.2019 20:08, Eric Robinson 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. > Access logs is the first thing to look at of course (just in case you are subject to some DoS attack), but other things of interest : 1) what is "the webapp" in question ? Any reason to suspect it may have been been hijacked, to do something it is not supposed to do ? does the webapp allow for clients to upload "things" to the server (files, documents, images,..) ? 2) if you look at the tomcat logs, do you recognise all the webapps which get deployed when tomcat starts ? Or is there an alien there ? 3) if you run "top" again, then enter a "c" in the console, it will show more details about the "java" command it is running. Similarly, doing a "ps -ef" command and comparing the result (by PID) with the top output, may give more details. That would show (us) at least the startup parameters of your tomcat(s). 4) speaking as a faithful Tomcat Committer, we always like to repeat that in 99% of the cases it turns out that the problem is with the webapp, not with Tomcat. The fact that in your case, you have changed about everything except the webapp, and the problem persists, would only tend to increase that suspicion.. So, can the webapp do any logging that would show what it's doing, while it is happily slurping all your CPU time ? 6) does the tomcat error log show anything of interest ? 7) under Linux as root, enter : netstat --tcp -pan | grep LISTEN (Shows all TCP ports your server is listening to, and which PID/processes control these ports). Anything unexpected there ? worse : anything unexpected which would match the PID of one of your tomcats ? André > --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. 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. 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