Forum Discussion

yamashin55's avatar
Jan 27, 2021

How to disable the global default-eviction-policy on a Virtual Server

I want to disable the global default-eviction-policy on my Virtual Server.

 

Should I set "Eviction Protected" to ”Enabled” in the Virtual Server settings?

 

 

 

  • Hi,

     

    If you want non-default values, you should create a custom eviction policy and associate the eviction policy to the virtual server.

     

    Normally all flows are treated equally when it comes to the aggressive sweeper. In certain circumstances this can cause important flows (e.g. from/to host processes bigd, routing with ZebOS, etc.) being reaped when the aggressive sweeper kicks in. The Eviction Protected flag tells the sweeper to handle important flows differently.

     

    So BIG-IP administrators can mark virtual servers as "important" by setting the 'eviction-protected' attribute to 'enabled' - by default it is disabled. When a listener is protected its flows will not be affected by any eviction policy.

    Normal - not protected - flows may be expired early when the global sweeper aggressiveness is between 20% and 90%. 

    Protected flows will not be expired early in this case, but might be expired randomly when aggressiveness reaches 90% and beyond.

     

    To prevent protected flows from ever being expired the BigDB variable Connection.AdaptiveReaper.NeverReapProtectedFlows can be set to 'enable' ('disable' by default).

     

    My 2 cents.

     

     

  • Hi,

     

    If you want non-default values, you should create a custom eviction policy and associate the eviction policy to the virtual server.

     

    Normally all flows are treated equally when it comes to the aggressive sweeper. In certain circumstances this can cause important flows (e.g. from/to host processes bigd, routing with ZebOS, etc.) being reaped when the aggressive sweeper kicks in. The Eviction Protected flag tells the sweeper to handle important flows differently.

     

    So BIG-IP administrators can mark virtual servers as "important" by setting the 'eviction-protected' attribute to 'enabled' - by default it is disabled. When a listener is protected its flows will not be affected by any eviction policy.

    Normal - not protected - flows may be expired early when the global sweeper aggressiveness is between 20% and 90%. 

    Protected flows will not be expired early in this case, but might be expired randomly when aggressiveness reaches 90% and beyond.

     

    To prevent protected flows from ever being expired the BigDB variable Connection.AdaptiveReaper.NeverReapProtectedFlows can be set to 'enable' ('disable' by default).

     

    My 2 cents.

     

     

    • yamashin55's avatar
      yamashin55
      Icon for Cirrus rankCirrus

      Thank you for the detailed explanation. It was very helpful !