Forum Discussion

rjordan's avatar
Icon for Nimbostratus rankNimbostratus
Jan 12, 2011

Base member status on another member's monitor

We are hosting a couple HTTP apps for a customer. They have two web servers in their cluster. We have 3 virtual servers, each having their own pool with unique IPs. Here is what it looks like:















Their "main" app is running on VS-1. If a pool member goes down in Pool-1, the members from the same server on Pool-2 and Pool-3 should be marked as down. For example, if goes down, and should also be marked down.



I can think of two simple workarounds:


1. Configure all virtual servers to use the same pool and require the customer to reconfigure the web server bindings.


2. Create two monitors and set the IP alias to and and assign them to the appropriate members in Pool-2 and Pool-3.



The first solution isn't really viable because they can't use named based hosting on their web server. The second solution would involve 3x the health checks, which the customer is trying to stay away from.



I'm assuming this can be done with iRules, but I haven't done anything like this before. I'm not too sure about parsing the list of active members. Below is a draft of what I think would work. Is anyone doing anything similar? Or is there a better way to do this?





set members [active_members -list Pool-1]


if { not (members [contains]) } {


LB::down pool Pool-2 member 80 }


if { not (members [contains]) } {


LB::down pool Pool-2 member 80 }


pool Pool-2