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Fan_124026's avatar
Fan_124026
Icon for Nimbostratus rankNimbostratus
Jul 19, 2017

uneven load balance issue, want to try persist source port on particular server

Good Day,

 

I have one issue for uneven load balananeing and it only seen comming from particularly 4 x air-watch server as a source, rest of clients to the same VS are evenly load balanced.

 

F5 TAC looked and advised uneven load balance is expected because we are using persist source address, they are hundred client connections behind each air-watch server, when have default persist source address, connections from individual air-watch server will keep using one pool member in the pool.

 

I want to try persist source port and only apply to these 4 x air-watch servers. Can some of your expert having a look at irule config below and advise if it is looking all right? Thank you.

 

when HTTP_REQUEST {

 

if {{ [IP::client_addr] eq "192.168.0.10" } || { [IP::client_addr] eq "192.168.0.20" } || { [IP::client_addr] eq "192.168.0.120" } || { [IP::client_addr] eq "192.168.0.140" } } {

 

persist persist uie "[TCP::client_port]" 3600

 

else { persist source_addr }

 

application delivery
BIG-IP
devops
iRules

1 Reply

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  • Patrik_Jonsson's avatar
    Patrik_Jonsson
    Icon for MVP rankMVP
    Jul 20, 2017

    Hi!

     

    There's no need to write a rule to persist on source port as the F5 device would do that automatically by default if no persistence profile has been added.

     

    Reason being that no member switch would be done in mid-session (unless you're using re-select as Action On Service Down, which requires does not work unless in special scenarios). Even if you did persist on source port there would be a new source port for each new TCP session, so essentially you'd accomplish nothing.

     

    My suggestion would be to disable persistence for the virtual server entirely, or specifically for the airwatch servers. Not sure if you'd gain much by doing so though unless they open up multiple connections per server?

     

    /Patrik