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    Very high CPU usage every 15 minutes

    Scheduled Pinned Locked Moved General pfSense Questions
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    • stephenw10S Offline
      stephenw10 Netgate Administrator
      last edited by

      How large is the rules.debug file?

      What CPU is that?

      That looks pretty extreme.

      Steve

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      • V Offline
        ViniciusBr @stephenw10
        last edited by

        @stephenw10 said in Very high CPU usage every 15 minutes:

        How large is the rules.debug file?

        What CPU is that?

        That looks pretty extreme.

        Steve

        Yes, it is pretty bad, looking forward to fix it.

        Where is this file located? /tmp? If yes it is currently 38K
        38 -rw-r--r-- 1 root wheel 38K Sep 15 20:45 /tmp/rules.debug

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        • V Offline
          ViniciusBr
          last edited by

          CPU Type Intel(R) Celeron(R) CPU G470 @ 2.00GHz
          AES-NI CPU Crypto: No

          Thanks!

          provelsP 1 Reply Last reply Reply Quote 0
          • provelsP Offline
            provels @ViniciusBr
            last edited by

            @ViniciusBr Are you using a ramdisk or hard drive for /tmp?

            Peder

            MAIN - pfSense+ 24.11-RELEASE - Adlink MXE-5401, i7, 16 GB RAM, 64 GB SSD. 500 GB HDD for SyslogNG
            BACKUP - pfSense+ 23.01-RELEASE - Hyper-V Virtual Machine, Gen 1, 2 v-CPUs, 3 GB RAM, 8GB VHDX (Dynamic)

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            • V Offline
              ViniciusBr
              last edited by

              Same HD, one for everything... this started to happen not long ago.

              Before all were ok.

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              • stephenw10S Offline
                stephenw10 Netgate Administrator
                last edited by

                Hmm, how long does it take to reload the filter? I have a 35k ruleset here and it does use ~100% of one CPU core while it reloads but it takes maybe 1s to do it.

                You have something that is triggering the filter reload every 15mins. Check the system logs.

                Steve

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                • V Offline
                  ViniciusBr @stephenw10
                  last edited by

                  @stephenw10 said in Very high CPU usage every 15 minutes:

                  Hmm, how long does it take to reload the filter? I have a 35k ruleset here and it does use ~100% of one CPU core while it reloads but it takes maybe 1s to do it.

                  How can I check how long it is taking to reload?

                  About the logs: cannot find anything useful there.

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                  • stephenw10S Offline
                    stephenw10 Netgate Administrator
                    last edited by

                    Go to Status > Filter Reload, hit the button there. If you have top open in a console at the time you can see how it actually behaves.

                    Steve

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                    • V Offline
                      ViniciusBr @stephenw10
                      last edited by

                      @stephenw10 said in Very high CPU usage every 15 minutes:

                      Go to Status > Filter Reload, hit the button there. If you have top open in a console at the time you can see how it actually behaves.

                      Steve

                      Ok, so that is the way of reproducing the issue!

                      Got the same high CPU usage, just not sure how to troubleshoot from there.

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                      • stephenw10S Offline
                        stephenw10 Netgate Administrator
                        last edited by

                        Does it show any errors on the reload page? Does it take more than a few seconds?

                        Something is triggering that reload, probably a result of something else being updated like an alias perhaps. I'd be amased if nothing shows in the system log though. Can we see it?

                        Steve

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                        • V Offline
                          ViniciusBr @stephenw10
                          last edited by ViniciusBr

                          @stephenw10 said in Very high CPU usage every 15 minutes:

                          Does it show any errors on the reload page? Does it take more than a few seconds?

                          Something is triggering that reload, probably a result of something else being updated like an alias perhaps. I'd be amased if nothing shows in the system log though. Can we see it?

                          Steve

                          It is taking around 25 seconds to complete.

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                          • stephenw10S Offline
                            stephenw10 Netgate Administrator
                            last edited by

                            Hmm, no errors that jump out there. It's quite a long list though. 25s seems waaay longer than I might expect. It may be resolving a load of things.

                            I meant the system log though. Covering at least, say, 30mins so we can see a reload cycle.

                            Steve

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                            • V Offline
                              ViniciusBr
                              last edited by

                              I don't see anything strange:

                              pf-logs.JPG

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                              • stephenw10S Offline
                                stephenw10 Netgate Administrator
                                last edited by

                                Hmm, sure looks like it's reloading the rules. And not at 1h intervals.

                                If you install the cron package when cron jobs are listed? (or just check the crontab)

                                Steve

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                                • V Offline
                                  ViniciusBr
                                  last edited by

                                  Here we go:

                                  pf-cron.JPG

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                                  • stephenw10S Offline
                                    stephenw10 Netgate Administrator
                                    last edited by

                                    Ok so it's the filter_configure_sync cronjob. That is created if you have scheduled firewall rules.

                                    Do you need those rules?

                                    Of course it shouldn't be anything like the hit you're seeing to run it.

                                    Steve

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                                    • V Offline
                                      ViniciusBr
                                      last edited by

                                      @stephenw10 said in Very high CPU usage every 15 minutes:

                                      filter_configure_sync cronjob. That is created if you have scheduled firewall rules

                                      I just deleted the schedule and removed the schedule from the rule, I will monitor and will get back here.

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                                      • V Offline
                                        ViniciusBr
                                        last edited by

                                        So the 15 minutes spike is over, but the filter reload is still consuming loads of CPU, not as before, but still high (yellow are is after the schedule deletion):
                                        pf-cpu.JPG

                                        Checking the logs I can only see the filter reload:

                                        pf-logs2.JPG

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                                        • stephenw10S Offline
                                          stephenw10 Netgate Administrator
                                          last edited by

                                          Yeah it still has to reload the ruleset whenever it changes, pfBlocker updated in that instance.

                                          Is it actually causing a problem though? You would expect it to use as much CPU as available to load the ruleset in the shortest possible time but won't necessarily effect other processes.

                                          Steve

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                                          • V Offline
                                            ViniciusBr
                                            last edited by

                                            Well, the thing is: I have other pfsense boxes and they all have this 15 minute spike, but they don't go above 6% cpu usage, a few of them use less than 1%.. I know that several factors can cause this difference, but I still don't see why this huge CPU usage.

                                            Thanks so far for the help!

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