iRule behavior when pools are down

hello,

 

 

 

 

You can handle this situation intelligently when this occurs.

 

 

There could be 2 scenarios when pool is "down":

 

 

 

1. All pool members are down [ health check failed ] or disabled manually or connection limit reaches - high demand

 

2. Pool is emtpy [ yes you can have an empty pool in LTM :) ]

 

 

In my opinion, your iRule will look like this:

 

 

when HTTP_REQUEST {

 

if { [HTTP::host] starts_with "host1" } {

 

 

check if all members are down or disable then send to virtual waiting room that may send you back for retry

 

if { [active_members srvpool1] == 0 } {

 

HTTP::redirect "http://sorry.domain.com/pleasewait.html?[HTTP::host][HTTP::uri]"

 

}

 

 

check if pool is empty, means maintenance is in progress

 

if { ![members srvpool1] } {

 

 

log local0. "Pool is empty" ;

 

HTTP::redirect "http://sorry.domain.com/maint.html"

 

}

 

 

if all good then just proceed to the pool

 

pool srvpool1

 

 

} elseif { [HTTP::host] starts_with "host2" } {

 

pool srvpool2

 

} elseif { [HTTP::host] starts_with "host3" } {

 

pool srvpool3

 

} elseif { [HTTP::host] starts_with "host4" } {

 

pool srvpool4

 

} else {

 

pool default-pool

 

}

 

}

 

 

Hope it helps.