Description

This article provides the necessary commands to collect data when experiencing high Input/Output Card (IOC) CPU utilization on SRX high-end devices. 


The collected data will help in diagnosing and troubleshooting the issue effectively.

Symptoms

High CPU utilization observed on an IOC

 

No significant impact on user traffic in most cases

 

Below is the command to check IOC CPU utilization:

 

root@fw1>show chassis fpc
                         Temp    CPU Utilization       (%)   CPU Utilization       (%)  Memory       Utilization (%)
Slot State            (C)      Total  Interrupt      1min   5min   15min        DRAM (MB)         Heap     Buffer
  0  Online             0       4          0                  4       3          3                  2048                  42         57

  3  Online            31     80         53               80     80     80                    2048                  6         16

Solution

To diagnose high CPU utilization on FPC3, execute the following commands twice at a 5-minute interval while the issue is occurring.


Data Collection Commands


set cli timestamp


show chassis fpc


If the IOC is part of a chassis cluster, replace the below fpc3 with node0.fpc3 or node1.fpc3 accordingly.



request pfe execute target tnp tnp-name fpc3 command "show sched"

request pfe execute target tnp tnp-name fpc3 command "show syslog messages"

request pfe execute target tnp tnp-name fpc3 command "show nvram"

request pfe execute target tnp tnp-name fpc3 command "show threads cpu"

request pfe execute target tnp tnp-name fpc3 command "show threads verbose"

request pfe execute target tnp tnp-name fpc3 command "show threads XXX"


(Replace XXX with the top thread ID from the previous output)


Example of High CPU Top Thread Output


If the issue occurs again, capture the top thread details using the show sched command. Below is an example output:


request pfe execute target tnp tnp-name fpc3 command "show threads cpu"


Output:


CPU load is 34% (1 second), 16% (5 second), 18% (10 second), 19% (1 minute)


 CPU  Name  Time(ms)

 82%  Idle  25095519102

 17% Threads  5439200042


 **Top Thread:**

 **pid  = 95** # Example showing top thread is pid 95

 **name  = Cassis Free Timer**

 **time  = 1090233103 ms**

 **cpu  = 3%**


To collect more details about the top thread (pid 95 in this case):


request pfe execute target tnp tnp-name fpc3 command "show threads 95"


Modification History

2025-03-14 : Article Created