Modify priority of pool members using iRules

it seems this may not be suitable for situations requiring prioritisation of nodes within the pool though?

is LB::status useful (i.e. manually select pool member for the first request)?

e.g.

 config

root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) list ltm virtual bar
ltm virtual bar {
    destination 172.28.24.10:80
    ip-protocol tcp
    mask 255.255.255.255
    pool foo
    profiles {
        http { }
        tcp { }
    }
    rules {
        qux
    }
    source 0.0.0.0/0
    source-address-translation {
        type automap
    }
    vs-index 41
}
root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) list ltm pool foo
ltm pool foo {
    members {
        200.200.200.101:80 {
            address 200.200.200.101
            session monitor-enabled
            state up
        }
        200.200.200.111:80 {
            address 200.200.200.111
            session monitor-enabled
            state up
        }
    }
    monitor gateway_icmp
}
root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) list ltm rule qux
ltm rule qux {
    when CLIENT_ACCEPTED {
  if { [persist lookup uie 1] ne "" } {
    persist uie 1
  } else {
    if { [LB::status pool foo member 200.200.200.111 80] eq "up" } {
      pool foo member 200.200.200.111 80
    }
  }
}
when SERVER_CONNECTED {
  persist add uie 1
}
}

 persistence

root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) show ltm persistence persist-records all-properties
Sys::Persistent Connections
universal - 172.28.24.10:80 - 200.200.200.111:80
------------------------------------------------
  TMM           0
  Mode          universal
  Value         1
  Age (sec.)    6
  Virtual Name  /Common/bar
  Virtual Addr  172.28.24.10:80
  Node Addr     200.200.200.111:80
  Pool Name     /Common/foo
  Client Addr   200.200.200.111
  Local entry

universal - 172.28.24.10:80 - 200.200.200.111:80
------------------------------------------------
  TMM           1
  Mode          universal
  Value         1
  Age (sec.)    6
  Virtual Name  /Common/bar
  Virtual Addr  172.28.24.10:80
  Node Addr     200.200.200.111:80
  Pool Name     /Common/foo
  Client Addr   200.200.200.111
  Owner entry

Total records returned: 2

by the way, if you want to change pool member priority value, i think alertd or icall may be applicable.

Acton on Log - using the alertd deamon

iCall - All New Event-Based Automation System by Jason Rahm