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kbk4912
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Oct 12, 2023

What happens when you disable a monitor/all monitors for a pool?

Have a question for all the big-ip folks out there, what happens when you do that? Say you disbale all monitors for a particluar pool which is being used by a virtual server then when a failover happens to the standby f5 big-ip member then will it not failover for this particular server since the monitoring is disabled so f5 doesnt know if pool/servers in the pool are up therefore doesnt failover this particular virtual server?

Is that what happens? Just asking since im not sure what the disadvantages of disabling it are, i have disabled monitoring for a particular virtual server since the monitor probes that the backend servers in the pool were receving were causing some errors on those servers so had to disable it until they figure out what those errors are/ fix them.

Thank You.

3 Replies

  • If you are in an Active/Standby scenario, then all your virtual servers are always served by the active node, thus after a failover they all switch to the new active node independently of whether the underlying pools are monitored or not.  

    Monitoring is something tied to pool members and/or nodes, the VS is just ineheriting whatever status it observes from its attached pool. If you disable monitoring (pool and VS become blue), then the active F5 will just send traffic to the selected pool member without caring about its state, spray and pray, that is the actual disadvantage 

  • Without monitoring, the BIG-IP assumes BE servers are always available and performs load balancing according to the configuration in the pool object for that service.
    As Amine said, this does not impact how F5 publishes the VIP. All objects in the Traffic Group that your VS belongs to are served by the Active node for that T.G. , and when a failover happens everything (including the disabled VIP) starts to be served by the new Active peer.

  • Hi kbk4912

    When you remove all monitor from Pool, The status on pool will change to blue squre and it receive all reqeust from client without health check to server for guaruntee service available or not, You have to apply health monitor to pool for ensure service ready

    Overview of colored status icons in the Configuration utility (f5.com)

    In this case you ask about failover, i'm not sure that you mean you use this pool for gateway failover or not ?