Forum Discussion

Grant_Mitchell_'s avatar
Grant_Mitchell_
Icon for Nimbostratus rankNimbostratus
Mar 03, 2014

Mark an LTM virtual down when pool in an irule is down.

We have and LTM virtual with an attached pool and an irule that references another pool. When the members of the attached pool are down but the pool in the iRule is up, the virtual stays up. Is there a command we can put in the iRule to down the virtual when the attached pool is down?

 

application delivery
availability
devops
iRules
LTM

6 Replies

  • Hamish's avatar
    Hamish
    Icon for Cirrocumulus rankCirrocumulus
    Mar 03, 2014

    Nope... But what you could do is put a monitor on the default pool that checks the pool the iRule references... [e.g. An external monitor or a built-in transparent monitor - but you'd need one of those per member of the iRUle referenced pool)

     

    H

     

  • Kevin_Stewart's avatar
    Kevin_Stewart
    Icon for Employee rankEmployee
    Mar 04, 2014

    I think it really depends on what you mean by "down". If you mean that you don't want to send any traffic to the iRule-referenced pool based on availability of the attached pool, then you could use the active_members command:

     

    https://devcentral.f5.com/wiki/iRules.active_members.ashx

     

    If, however, you need the VIP to be disabled completely, perhaps so that GTM will see it as down, then you could use an iCall (or raw user_alert.conf script) to effectively disable the VIP by triggering TMSH commands on Syslog monitor events.

     

    https://devcentral.f5.com/questions/clearing-machine-cache

     

  • Dan_Pacheco's avatar
    Dan_Pacheco
    Icon for Cirrus rankCirrus
    Nov 16, 2017

    If you use a Traffic Policy instead of an iRule on v12.1.2 you don't get the same behavior as the irule. The VS goes down even if the path-match pool is up. I have successfully tested. Hopefully F5 doesn't screw it up in a new OS version to make Traffic Policies more like iRules.

     

  • Alexander_Poly1's avatar
    Alexander_Poly1
    Icon for Altocumulus rankAltocumulus
    Dec 04, 2017

    In version 13, when you drop all pools in traffic policy - the VS does not goes down(. Maybe i miss something. Dan Please show your settings.

     

    • Dan_Pacheco's avatar
      Dan_Pacheco
      Icon for Cirrus rankCirrus
      Dec 05, 2017

      Hi Alexander, What I am trying to achieve is the opposite of that. We drop the default pool, and the VS goes down, even if the policy has a pool that is passing healthcheck. I just tested this out in the lab on a v13.0.0 HF3 VE and the behavior is consistent with v12.1.2. Hope this helps.

          root@(DCO-F5VE-LAB-3)(cfg-sync Standalone)(Active)(/Common)(tmos) list ltm policy
    ltm policy test_policy {
        controls { forwarding }
        last-modified 2017-12-05:08:25:42
        requires { http }
        rules {
            test {
            actions {
                0 {
                    forward
                    select
                    pool https_pool_anoel1
                }
            }
            conditions {
                0 {
                    http-uri
                    path
                    contains
                    values { /admin }
                }
            }
        }
    }
    status published
    strategy first-match
}
root@(DCO-F5VE-LAB-3)(cfg-sync Standalone)(Active)(/Common)(tmos) list ltm poo
ltm pool http_pool_default {
    members {
        dcosvrlab-1:http {
            address 10.15.60.43
            session monitor-enabled
            state down
        }
        dcosvrlab-2:http {
            address 10.15.60.44
            session monitor-enabled
            state down
        }
        dcosvrlab-3:http {
            address 10.15.60.45
            session monitor-enabled
            state down
        }
    }
    monitor failing-monitor 
}
ltm pool https_pool_anoel1 {
    members {
        dcosvrlab-1:https {
            address 10.15.60.43
            session monitor-enabled
            state up
        }
        dcosvrlab-2:https {
            address 10.15.60.44
            session monitor-enabled
            state up
        }
        dcosvrlab-3:https {
            address 10.15.60.45
            session monitor-enabled
            state up
        }
    }
    monitor tcp 
}
root@(DCO-F5VE-LAB-3)(cfg-sync Standalone)(Active)(/Common)(tmos) list ltm virtu
Components:
  virtual           virtual-address   
root@(DCO-F5VE-LAB-3)(cfg-sync Standalone)(Active)(/Common)(tmos) list ltm virtual
ltm virtual test {
    destination 1.1.1.1:http
    ip-protocol tcp
    mask 255.255.255.255
    policies {
        test_policy { }
    }
    pool http_pool_default
    profiles {
        http { }
        tcp { }
    }
    source 0.0.0.0/0
    translate-address enabled
    translate-port enabled
    vs-index 2
}`text`