log some message when servers connections exceed a connection value

You can incorporate LB::Select option to know which pool members were selected. https://clouddocs.f5.com/api/irules/LB__select.html

 

Code

when HTTP_REQUEST { log local0. "lbserveraddr: [LB::server addr]" check if serverside connection had previously been established if { [LB::server addr] eq "" }{ if no serverside connection had previously been established, force one so the iRule has the info required to insert a destination-specific header eval [LB::select] } switch [LB::server addr] { "172.16.5.80" { HTTP::header replace Host www1.customer.com } "172.16.5.81" { HTTP::header replace Host www2.customer.com } "172.16.5.82" { HTTP::header replace Host www3.customer.com } } }