topic Management CPU high in 8.1.7 (just upgraded), bug? in General Topics

Management CPU high in 8.1.7 (just upgraded), bug?

BigPalo — Tue, 06 Aug 2019 14:13:05 GMT

Hi,

We just upgraded from 8.0.11 to 8.1.7. And in this new version 8.1.7 the CPU MGMT is high (90-100%). I attach the top output:

what is "pan_task"? its consuming lot of CPU. Any bug related to this in 8.1.7?

show system resources

top - 16:11:02 up 2:06, 2 users, load average: 5.21, 5.52, 5.58
Tasks: 161 total, 6 running, 155 sleeping, 0 stopped, 0 zombie
Cpu(s): 65.7%us, 1.2%sy, 5.7%ni, 27.2%id, 0.1%wa, 0.0%hi, 0.1%si, 0.0%st
Mem: 4119472k total, 3498192k used, 621280k free, 59756k buffers
Swap: 2008088k total, 888k used, 2007200k free, 1628128k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3318 20 0 74712 35m 8424 R 100.0 0.9 124:55.50 pan_task
3320 20 0 49940 10m 8360 R 100.0 0.3 124:55.80 pan_task
3322 20 0 49984 11m 8448 R 100.0 0.3 124:55.46 pan_task
3319 20 0 49940 10m 8304 R 99.4 0.3 124:55.79 pan_task
3321 20 0 50112 10m 8272 R 99.4 0.3 124:55.59 pan_task
2996 20 0 40220 5376 3876 S 5.7 0.1 0:32.50 ehmon
3562 20 0 553m 209m 127m S 1.9 5.2 1:20.35 useridd
11059 20 0 17984 7036 1900 R 1.9 0.2 0:00.04 top
1 20 0 3212 736 688 S 0.0 0.0 0:00.30 init
2 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd
3 20 0 0 0 0 S 0.0 0.0 0:01.66 ksoftirqd/0
5 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:0H
7 RT 0 0 0 0 S 0.0 0.0 0:00.08 migration/0

Re: Management CPU high in 8.1.7 (just upgraded), bug?

kiwi — Tue, 06 Aug 2019 14:39:35 GMT

Hi @BigPalo ,

The Pan_task are the threads in the dataplane, where the packets are processed , and they would always show values like 99% or 100%. It is a legitimate value and means that the dataplane is busy processing all the packets that it receives.

This was also discussed here:

About-process-pan-task-of-dp-monitor-log

Cheers !

-Kiwi.

Re: Management CPU high in 8.1.7 (just upgraded), bug?

aleksandar.astardzhiev — Fri, 09 Aug 2019 07:53:55 GMT

Hi @BigPalo,

What model are you running?

I am asking because a few months ago I notice something similar for a brand new PA-820. Before this device we had only PA-3000 and PA-5000 series. So I opened a case to TAC and the engineer was very kind to give me a very nice explanation:

The difference between those platforms (PA-3000 and PA-5000) and PA-8XX is that they have a dedicated dataplane. For platforms like PA-8XX and PA-2XX with one CPU there are always some cores dedicated to MP and others for DP, and the DP cores of that single CPU are generally maxed out.