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answ161's avatar
answ161
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Aug 23, 2023

Higher Monitor CPU Usage in v16

Hi All, After an attempted upgrade of our production BIG-IPs (i4600 HA pair) from v14 to v16 earlier this year that required a rollback due to high CPU utilization, I have been doing testing on some...
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AndreiHurmuz's avatar
AndreiHurmuz
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Nov 21, 2023

Hi answ161 

did you get any resolution on that issue? We are experimenting the same problem with v16, as of now 4 systems have increased CPU usage since the update, VE and HW Big-Ip. 

Many thanks in advance!

 

answ161's avatar
answ161
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Nov 21, 2023

Hi AndreiHurmuz,

In my configuration, F5 support helped to determined that LDAP monitors in v16 are the cause of higher CPU utilization.  Removing LDAP monitors caused CPU to drop by about 15%.  However, the reason why LDAP monitors use more CPU in v16 is not known.  

This may not be the cause in your case, but top output should confirm this. 

  • AndreiHurmuz's avatar
    AndreiHurmuz
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    Nov 21, 2023

    Thank you for the quick reply, i do not think this is my issue, as far as i have gathered i think for our case Java could be the issue. I will open a case and see where that goes. Thanks again for the update!

    • holge's avatar
      holge
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      Nov 21, 2023

      Hi AndreiHurmuz 

      I worked with F5 support on the issue. The comment from them was;

      Yes, a some CPU usage increase after upgrading to a later major software release is expected due to additional features in the new software version. However, this should not affect production traffic. If it does, we have to review the configuration and adjust things until we get this under control.

      So some CPU rise is expected. We needed to look at cleaning up our config. Some standouts aside from the LDAP monitors mentioned by answ161  is halfopen monitors. We had a lot of them and they put load on CPU. Also if you have a lot of pool members that are down, the system is constantly waiting for responses from those members.

      Cheers