Controller Based WLANs

Difference between command output "show cpuload and "show cpuload current" on controllers?

Aruba Employee

Environment         No specific environment as this would be command.

 

(Aruba7240) #show cpuload

 

user 29.5%, system 61.6%, idle 8.9% ===================This may not the right command and this idle percentage will be calculating different values.

Show cpuload current gives out the exact CPU usage for individual process.

See below for more explanation

 

  1. Show cpuload
    • This CLI uses a direct kernel interface to return a pre-calculated average of CPU usage across all the control plane CPUs. Kernel on every timer interrupt keeps such statistics which this CLI uses and displays.
    • It can be used to get a knowledge of system usage as a whole. In this we don’t try to demarcate what processes in what space (user or kernel) are taking up the CPU.
    • It just tells how much, system as a whole, is busy and where.
  2. Show cpuload current
    • This CLI uses top2 command internal to display the stats.
    • top2 command works on sampling per CPU usage. Thus is need 1 or 2 consecution runs to come to an exact system load.
    • The CLI runs the command in single-shot mode and displays the output. As a result of which, the 3rd line doesn’t give correct system usage. If you run top2 command from the shell prompt, without any options, you will see that first display shows incorrect usage in 3rd line. But in further displays it will converge and come to correct value.
    • This CLI should be used to check the exact per-process CPU utilisation. This also is instantaneous but it decouples per-CPU process scheduling and usage. Hence tells exact CPU usage each process is having in SMP systems.
  3. Show processes sort-by cpu
    • This CLI uses the ps command to show the output.
    • The CPU utilisation here should be at par with “show cpuload current”. But this command also works on instantaneous samplings. In case of momentary peak or a delay between  runs of “show cpuload current” and this CLI, there might be a difference in the output.


From highlighted output we could notice CPU utilization is 97.2% idle with 1.2% for users and 1.4% for system which is good.

Show cpuload current

 

op2 - 13:50:37 up 47 days, 15:40,  0 users,  load average: 21.05, 19.49, 14.00

Tasks: 191 total,  22 running, 169 sleeping,   0 stopped,   0 zombie

Cpu(s):  1.2%us,  1.4%sy,  0.0%ni, 97.2%id,  0.0%wa,  0.0%hi,  0.1%si,  0.0%st

Mem:   5715712k total,  2862592k used,  2853120k free,   140224k buffers

Swap:        0k total,        0k used,        0k free,   596608k cached

 

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND           

28686 nobody    20   0  231m  25m 7168 S  121  0.5   0:02.91 httpd             

 3394 root      20   0  130m  16m 4032 S   18  0.3 615:07.31 mysqld            

 3552 root      20   0  387m 201m  30m S   12  3.6   1510:10 stm               

 3966 nobody    20   0 47936 8832 4096 S   11  0.2   3:40.01 httpd              

29003 nobody    20   0  8000 4736 3072 R   11  0.1   0:00.06 login             

29006 nobody    20   0  7808 2624 1344 R    9  0.0   0:00.05 login             

29009 nobody    20   0    64   64    0 R    9  0.0   0:00.05 httpd             

29011 nobody    20   0 45760 5824 1088 R    9  0.1   0:00.05 httpd             

29015 nobody    20   0 42688 5824 1088 R    9  0.1   0:00.05 httpd             

    4 root      20   0     0    0    0 S    7  0.0 210:59.90 ksoftirqd/0       

28967 nobody    20   0  7808 2624 1344 R    7  0.0   0:00.05 login             

29007 nobody    20   0  7808 2624 1344 R    7  0.0   0:00.04 login             

29008 nobody    20   0 43328 5824 1088 R    7  0.1   0:00.04 httpd             

29010 nobody    20   0 41152 5824 1088 R    7  0.1   0:00.04 httpd             

29013 nobody    20   0 39488 5824 1088 R    7  0.1   0:00.04 httpd             

29014 nobody    20   0 42688 5824 1088 R    7  0.1   0:00.04 httpd             

29016 nobody    20   0 39808 5888 1088 R    7  0.1   0:00.04 httpd             

29017 nobody    20   0 47936 5824 1088 R    7  0.1   0:00.04 httpd             

29019 nobody    20   0 46784 5824 1088 R    7  0.1   0:00.04 httpd      

Version history
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Last update:
‎11-11-2014 10:41 AM
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