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Bob_Z_148422's avatar
Bob_Z_148422
Icon for Nimbostratus rankNimbostratus
Dec 28, 2016

LTM VE: task using high CPU

Every now and then a task stats running at high CPU and causes a lag in normal transactions.

 

I see that five processes are created very frequently and I assume they are for a request going through the LTM. The command names are made up of ten random alpha characters and there are almost always five of them and they disappear very quickly.

 

However occasionally one of the task doesn't terminate and sometimes it uses 30% of the available CPU.

 

How can I diagnose what is happening?

 

application delivery
LTM

1 Reply

  • Patrik_Jonsson's avatar
    Patrik_Jonsson
    Icon for MVP rankMVP
    Dec 28, 2016

    Hey Bob!

    Try running this:

    watch -n1 "ps aux | awk '{if(\$3 > 10){ print \$0 }}' >> /var/tmp/psstat.log"

    What it does is to once per second capture the CPU usage of processes using more than 10% CPU (increase the limit if you see fit) and logs it into 

    /var/tmp/psstat.log

    Then you can sort it by running:

    cat /var/tmp/psstat.log | sort -rk 3,3

    If you can paste the rows containing the mysterious process we might be able to figure it out.

    /Patrik