Down due to failure vs administratively down

Craig, this isn't possible. I'd suggest anyway that you look for a process related solution. If you're performing maintenance then why not manually force the redirection to the maint. page as part of the task?

Is there a way in an iRule to differentiate between members that are down due to a failure versus administratively down?

is LB::status pool usable?

 

 

LB::status wiki

 

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

 

There are a few ways to handle this I think. Sending a user to a sorry page in an LB_FAILED event is pretty straight forward, as Nitass states, using the LB::status command:

when LB_FAILED {
   if { [LB::status pool $poolname member $ip $port] eq "down" } {
      log "Server $ip $port down!"
   }
}

You may also want to consider looping through the nodes in the pool to find a good one before simply sending a sorry page. Take a look at the HTTP::retry page for a few examples:

https://devcentral.f5.com/wiki/irules.http__retry.ashx

This will loop through nodes that are technically available, but are returning "bad" values (40x or 50x messages). In the event that all of the nodes are down, however, if you want to differentiate between all nodes down because of monitor failures (a sorry page) versus all nodes down because they were disabled (a maintenance page), there are at least two options that I can think of:

1. As you loop through the pool members in your LB_FAILED event (using the members command to enumerate the pool members), take note of their status. At the end of the loop, if more are disabled than failed, send the maintenance page.

2. Configure an external monitor script that queries the monitor status of all of the pool members, and then writes the down or disabled status to a data group. I'd use a "phantom" monitor, one that is attached to a pool, but not a pool that is assigned to a virtual server, or that cares about the actual pool members. Assigning a monitor to a pool simply activates the monitor. Then use a tmsh command like the following to record the status of a given pool and its members:

tmsh show ltm pool local-pool members { 10.70.0.4:http } detail |grep Reason |grep -v pool |awk -F": " '{ print $2 }'

This command will report one of the following states:

- "Pool member is available"

- "Pool member is available, user disabled"

- "Pool member has been marked down by a monitor"

- "Forced down"

So like before, if ALL of the members are down or disabled, and the majority are disabled, mark the data group entry accordingly. On an LB_FAILED event, read the data group and respond to the client request.