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Martijn_van_de1's avatar
Martijn_van_de1
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Nov 08, 2017

CPU load while no traffic is passing BIGIP

Hi all,

 

Take a look at the graph below. This is the 7 day overview of the CPU load on a i4600 cluster BIGIP with LTM, APM, ASM and AFM provisioned. But for now only LTM is configured with about ten virtual servers. Nothing special, just LTM on internal webservers with a simple health check, client ssl profile and round robin load balancing. We see the same on the Standby BIGIP.

 

Now the strange part. This cluster isn't production yet, so no large amount of traffic is passing the BIGIP. Just one test user testing the applications which do not use large amount of active connections.

 

Can anyone explain why the CPU increases every day for some time and then drop again to lower levels? Is there a system process that runs every day? Is it the update check for the ASM signature database? And why do CPU 2 and CPU 6 not show the same? These CPU's remain low.

 

Regards, Martijn

 

 

application delivery
LTM
TMSH

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  • Jinshu's avatar
    Jinshu
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    Nov 08, 2017

    It's hard to explain without analysing the system. I have seen this when ASM running the back-end Analytics or datasync.

     

    Also it looks like your odd number CPU is going up because it is used by Control plane rather data. there should be a datasync process that runs each day which will run up the CPU and does use Java. It should not impact traffic, however.

     

    https://support.f5.com/csp/article/K16469

     

    https://support.f5.com/csp/article/K15003

     

    Hope this helps.

     

    -Jinshu