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catalyst 3750 high utilization

jackson.ku
Level 3
Level 3

Hi,

We have one Catalyst 3750 with higher CPU utilization. ( CPU utilization for five seconds: 36%/30%; one minute: 27%; five minutes: 28% ) The CPU utilization for the other Catalyst 3750 is below 10%

 

We execute "sh proc cpu sort | exc 0.00" many times and find process "Check heaps" with higher utilization :

switch#sh proc cpu sort
CPU utilization for five seconds: 36%/30%; one minute: 27%; five minutes: 28%
 PID Runtime(ms)   Invoked      uSecs   5Sec   1Min   5Min TTY Process
   4     1581593     71425      22143  8.94%  1.19%  0.91%   0 Check heaps     
  88      219985     14589      15078  0.79%  0.15%  0.12%   0 HULC Tcam Memory
 207       76592    525547        145  0.15%  0.11%  0.07%   0 IP Input        
 289         100       315        317  0.15%  0.10%  0.02%   1 Virtual Exec

 

The IOS version is 122-55.SE8. Please help to give me some advise to find the higher utilization issue.

 

Best Regards,

 

 

20 Replies 20

i dont see any other way to tell what is causing.

take the downtime and get the capture done during the MW.

Hi,

I execute debug command at production 3750 switch, from debug result, many traffic forward by software, it cause the slow network issue. Please kindly help to analysis it.

 

Also I tried to change 3750G switch to 3850 switch with same configuration, the count for sw forwarding not increase rapidly and no slow network issue. Is it the platform performance issue?

Best Regards,

Jackson Ku

Hi,

Hi,

I execute debug command at production 3750 switch, from debug result, many traffic forward by software, it cause the slow network issue. Please kindly help to analysis it.

 

Also I tried to change 3750G switch to 3850 switch with same configuration, the count for sw forwarding not increase rapidly and no slow network issue. Is it the platform performance issue?

 

please kindly provide the comment. Thanks a lot.

 

Jackson Ku

 

 

InayathUlla Sharieff
Cisco Employee
Cisco Employee

Agree with Leo there is considered to be normal. Need not have to worry.

Anyways below are the ways which will give you an idea if in case the CPU goes high what information you need to collect and how can you troubleshoot the same.

Link below can help you in doing the TS:

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750/software/troubleshooting/cpu_util.html

 

HTH

Dear 

 

Your CPU is getting high because of interrupt traffic, i got the same issue in our Cisco 3560 switches. May below link will help you. We resolved the issue as mentioned in the  below link.

 

1) Kindly check the input traffic of your interfaces and see which interface is making high (abnormality in traffic size) , you may need to concentrate on that port.

 

https://supportforums.cisco.com/discussion/12296301/cisco-3560-switch-high-utilization-because-interrupt-traffic

 

Regards,

Jubair.S

Naveen Venkateshaiah
Cisco Employee
Cisco Employee

Hi,

This is high CPU caused by interrupt.

CPU utilization for five seconds: 36%/30%; one minute: 27%; five minutes: 28%

share the below command output

show controllers cpu-interface    // 5times interval of 30 sec, capture and upload it in text file.

example

 

Pls share command out put which i asked abaove, i will look into the output and suggest you on further  investigation.

 

Regards,

Naveen

****rate if it is Helpful****

 

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