Forum Discussion

hunghsingchin's avatar
hunghsingchin
Icon for Altocumulus rankAltocumulus
Jan 08, 2024

Question about F5 DNS Prober Pool

Hello F5 Community,

I have a scenario that I need some clarification on. I have a virtual server (VS) configured with three health monitors, with monitoring intervals set at 10, 20, and 30 seconds respectively. This VS references a prober pool, which contains two members (using a round-robin strategy), namely GTM1 and GTM2, each from Data Center A and B respectively.

My question is, how exactly does the round-robin process work in this context? Do the three monitors each rotate through the prober pool independently? Also, the status of the VS is determined by the combined status of the three monitors. Is it possible that the status of these three monitors is determined by different members of the prober pool?

Thank you in advance for your assistance.

application delivery
  • T-Trust's avatar
    T-Trust
    Icon for Cirrostratus rankCirrostratus
    Jan 08, 2024

    Hi Hunghsingchin,

    So i think the behavior in this case that proble pool round robin select 1 GTM to monitor VS in data center and it use all health check to this vs

     

     

    • hunghsingchin's avatar
      hunghsingchin
      Icon for Altocumulus rankAltocumulus
      Jan 09, 2024

      So, are you suggesting that within the prober pool, the smallest unit of execution for tasks is the virtual server (VS), rather than the individual monitors? Does this mean that regardless of how many monitors a virtual server references, it is treated as a single entity by the prober pool during its polling cycle? However, each monitor has a different polling interval. For instance, if during a polling cycle, the prober pool selects gtm1 to execute monitoring tasks, and monitor 1 has just reached its 10-second interval and is due for execution, what happens to monitors 2 and 3 if they have not yet reached their respective intervals? Will they be executed as well?