100% cpu on 8x 3850 stack

[sebastianoassenza79]

An abnormal cpu utilization value was detected on switch 2 of my 8x 3850 module. From the device logs, there do not appear to be any traffic conflicts or loops that would affect its operation. This currently does not result in any inefficiencies.

Here are the related outputs below:

------------------ show process cpu sorted detailed ------------------

Core 0: CPU utilization for five seconds: 51%; one minute: 35%; five minutes: 25%
Core 1: CPU utilization for five seconds: 100%; one minute: 56%; five minutes: 40%
Core 2: CPU utilization for five seconds: 100%; one minute: 78%; five minutes: 67%
Core 3: CPU utilization for five seconds: 74%; one minute: 86%; five minutes: 96%

------------------ show processes cpu detailed ------------------

Core 0: CPU utilization for five seconds: 99%; one minute: 61%; five minutes: 33%
Core 1: CPU utilization for five seconds: 58%; one minute: 69%; five minutes: 46%
Core 2: CPU utilization for five seconds: 27%; one minute: 73%; five minutes: 68%
Core 3: CPU utilization for five seconds: 99%; one minute: 74%; five minutes: 91%

I would like to know if this 100% spike may be creating problems with the stack and if so, would it be worthwhile to update the firmware to try to resolve.

thanks in advance

[Flavio Miranda]

Hi

  I got a similar issue times ago and it was related a Bug. At that time Cisco told to me through a TAC case that the high CPU would not cause any network problem but every time we got an incident on the network, the first thing support team came up was the CPU. So, to fix it I upgrade the switch and it was fixed.

Which version are you at?

[sebastianoassenza79]

thank you very much Flavio for your reply.
i attach you a "show version running" apparently the switches software is from 2016, maybe you should update to avoid further problems.

[Flavio Miranda]

I recommend to upgrade to something areound 16.x.x

And 8 switches in stack is a lot. If possible, I also recomend 2 stack of 4. 

[Jitendra Kumar]

Please find the below CPU Utilization T-Shoot document.

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-3850-series-switches/117594-technote-hicpu3850-00.html

Thanks,

Jitendra

[sebastianoassenza79]

thank you jitendra
unfortunately the paper confirms that the problem is possibly caused by the version of ios I have installed on the stack. In the next few days I will see if I can update the firmware to fix the problem.

[MHM Cisco World]

SW#show processes cpu sort | exclude 0.0

share output of this please 

[sebastianoassenza79]

thank you for your reply MHM Cisco World
Unfortunately, I am currently offsite and cannot have access to the switches. In a few days I can post the requested output

thanks

[Leo Laohoo]

Post the complete output to the following commands: 

1. sh version
2. sh platform software status control-processor brief

[sebastianoassenza79]

thank you for your reply Leo Laohoo
unfortunately as I have already told MHM Cisco World at the moment I am offsite and cannot have access to the switches. In a few days I can post the requested output

thanks

[Leo Laohoo]

The stack is on 3.7.X. 
Please provide the output to the command "sh proc cpu sort | ex 0.00".