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NiHo_202842's avatar
NiHo_202842
Icon for Cirrostratus rankCirrostratus
Jan 13, 2016

Incorrect load balancing when disabling Oneconnect

Hello,   so sketch the situation; we have a $app-pool and an $app-report-pool. $app-pool serves the regular web interface, while $app-report generates reports and sends this to the user. Default p...
cookie persistence
devops
iRules
LTM
oneconnect
  • Hannes_Rapp_162's avatar
    Hannes_Rapp_162
    Jan 13, 2016

    Is the app-pool configured as Default Pool in your Virtual Server settings? If you conditionally select another pool, ie. the server-report1 pool in an iRule, you will need to include a 'Default or Else' clause in the iRule to 'Re-Confirm' your Default Pool. Just having the app-pool as your Default Pool setting in Virtual Server properties will not be enough.

    You may see a similar problem occuring in your environment:

    - Your first request to app-pool is routed correctly
- Your second request to app-pool is routed correctly
- .. All requests destined to app-pool are routed correctly, until the first occurence where a request is routed to server-report1 pool
- .. All the requests that should go to app-pool (default) thereafter are now incorrectly routed to server-report1 pool.

    For a solution, if you're using the 

    if
    conditional statement, append an 
    else
    statement to specify the app-pool as your default selection in iRule. If you're using 
    switch
    conditional statement, append a 
    default
    statement.

    Give it a try, if the conditions described match your configuration. This would be a generic iRule problem, not related to OneConnect by any means.

Kai_Wilke's avatar
Kai_Wilke
Icon for MVP rankMVP
Jan 13, 2016

Hi NiHo,

if you need to switch pools or persistence profiles without using a ONECONNECT profile, then you have to issue a 

[LB::detach]
command on every single change.

See the links below for further information...

https://support.f5.com/kb/en-us/solutions/public/7000/900/sol7964.html

https://support.f5.com/kb/en-us/solutions/public/9000/800/sol9800.html

https://devcentral.f5.com/wiki/iRules.LB__detach.ashx

BTW: You may also want to try the (experimental) syntax below, to implement a simple request flow mechanism, with the purpose to only detach the server-side connection and re-apply the pool settings when its required.

when CLIENT_ACCEPTED {
    set last_pool ""
}
when HTTP_REQUEST {
    if { [string tolower [HTTP::uri]] starts_with "/somepath" } then {
        if { $last_pool equals "my_pool_a" } then {
            do nothing
        } else {
            LB::detach
            pool my_pool_a
            set last_pool my_pool_a
        }
    } else {
        if { $last_pool equals "my_pool_b" } then {
            do nothing
        } else {
            LB::detach
            pool my_pool_b
            set last_pool my_pool_b
        }
    }
}

Cheers, Kai