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Yalkrif_99781's avatar
Yalkrif_99781
Icon for Nimbostratus rankNimbostratus
Mar 07, 2012

Multi cpu preformance

hi

 

 

we are using big-ip 3900 with 4 core's,we are running load tests on http virtual server with iRule and we see that one core (0) gets to 80% cpu while other core's are on 30%.

 

Any idea why this happening ?is there a why to see the Irule usage and in which Cpu?

 

 

 

thanks

 

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  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Mar 07, 2012
    Hi Yalkrif,

     

     

    Is the iRule CMP compatible? If not, that would explain why the first core has higher utilization. You can check using:

     

     

    tmsh show ltm virtual VS_NAME |grep -i cmp

     

    CMP : enabled

     

    CMP Mode : all-cpus

     

     

    If that's not it, what process(es) does top show running with high CPU utilization on CPU0?

     

     

    Aaron
  • Ron_Masson_7797's avatar
    Ron_Masson_7797
    Icon for Nimbostratus rankNimbostratus
    Mar 08, 2012
    How are you running the load tests exactly?

     

     

    If all of the traffic is coming from the same source IP/port and being sent to the same virtual server, it will hash to the same core.

     

     

    Ron

     

  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Mar 08, 2012
    That CMP wiki page should be a good start. Can you post an anonymized version of the iRule?

     

     

    Aaron
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Mar 12, 2012
    I think you should be able to change all the global variables in RULE_INIT to static variables to make the iRule CMP compatible. If you're using any of the currently global variables to store values that change over the course of a connection, you should replace them with session variables.

     

     

    https://devcentral.f5.com/wiki/iRules.static.ashx

     

     

    Aaron