iRule logic to use multiple pools to force GTM failover on VIP

[Kevin_Basler]

I have a VIP that has no status because the pool that it uses is determined by a policy. To add state to the VIP I've added the following iRule:

when HTTP_REQUEST {

if { [active_members pool1] == 0 } {

# log

} 

The VIP now shows a status of green (UP). When I disable the pool members in pool1, the VIP goes down and the GTM routes traffic to another data center.

Since I have a VIP that has multiple pools, I need to fail the VIP if any one pool member is down.

I've tried these examples:

if { [active_members pool1] == 0 } {

# log

} 

elseif { [active_members pool2] == 0 } {

# log

} 

elseif { [active_members pool3] == 0 } {

# log

} 

elseif { [active_members pool4] == 0 } {

# log

}

}

and...

when HTTP_REQUEST {

if { [active_members pool1] == 0 or [active_members pool2] == 0 or [active_members pool3] == 0 }r 

# log

}

}

When I take any one pool down, the VIP remains up.

Any suggestions?

Thanks

Kevin

[Enes_Afsin_Al]

Hi Kevin,

• Create an iRule:

ltm rule irule_poolstatus {
when HTTP_REQUEST {
    if { [active_members pool1] == 0 || [active_members pool2] == 0 || [active_members pool3] == 0 || [active_members pool4] == 0} {
        HTTP::respond 200 content "down"
    }
    else {
        HTTP::respond 200 content "up"
    }
}
}

• Create a Virtual Server with IP x.y.z.t and bind the iRule:

ltm virtual vs_poolstatus {
    destination 1.2.3.4:http
    ip-protocol tcp
    mask 255.255.255.255
    profiles {
        http { }
        tcp { }
    }
    rules {
        irule_poolstatus
    }
    serverssl-use-sni disabled
    source 0.0.0.0/0
    source-address-translation {
        type automap
    }
    translate-address enabled
    translate-port enabled
}

• Create a monitor with receive string:

ltm monitor http monitor_status {
    adaptive disabled
    defaults-from http
    interval 5
    ip-dscp 0
    recv up
    recv-disable none
    send "GET /\r\n"
    time-until-up 0
    timeout 16
}

• Create a pool, add the virtual server IP address as pool member and bind the monitor:

ltm pool pool_status {
    members {
        1.2.3.4:http {
            address 1.2.3.4
            session monitor-enabled
        }
    }
    monitor monitor_status
}

• Create second iRule:

when HTTP_REQUEST {
    if { [active_members pool_status] == 0} {
        # log
    }
}

• Add the iRule to main virtual server

first iRule and virtual server: for "up/down response"

pool and monitor: for receive a request to the virtual server and to see the "up/down" status

I couldn't find a shorter solution.