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Yalkrif_99781's avatar
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Mar 07, 2012

Multi cpu preformance




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?






5 Replies

  • 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?



  • 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.





  • That CMP wiki page should be a good start. Can you post an anonymized version of the iRule?



  • 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.