Forum Discussion

Martin_Vlasko's avatar
Martin_Vlasko
Icon for Altocumulus rankAltocumulus
Dec 18, 2017

Load balance to node in the same DC where VIP is active

Hi,   We have following (simplified) scenario:   Two data centers: DC1, DC2.   Two F5 LTMs, one LTM in each DC, they run in active/standby mode and have one VIP configured.   Two applicat...
application delivery
irule
iRules
location awarness
LTM
Farshad_249798's avatar
Farshad_249798
Icon for Cirrus rankCirrus

You need to track a unique local id somehow and then use irule to select pool member based on that id. Haven’t tested this but I would use tcl_platform(machine) to get hostname assuming they are different.

 

Simon_Blakely's avatar
Simon_Blakely
Icon for Employee rankEmployee
Dec 19, 2017

I hope the DC's have a low-latency interconnect for HA. I suspect that you will encounter unforseen issues with this implementation.

The only other recommendation I can make:

Shift the static variable declaration to RULE_INIT for efficiency 
when RULE_INIT {
    set f5 $static::tcl_platform(machine)
}
when CLIENT_ACCEPTED {
    if { $f5 equals "f5DC1.mydomain.com" } { 
        pool pool_APP_DC1_DC2
    } elseif { $f5 equals "f5DC2.mydomain.com" } {
        pool pool_APP_DC2_DC1
    } else {
        log local0. "Error: machine info invalid!"
        reject
    }
}