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gis-att_206935's avatar
gis-att_206935
Icon for Nimbostratus rankNimbostratus
Mar 02, 2017

Persistence Profile Timeout Element

Hello,

 

We use the Cookie Hash method in one of our persistence profiles. "Timeout" value set to 180 seconds.

 

What happens when a browser presents a cookie that whose hash value has "timed-out" of the persistence table? I am assuming that the Big-IP ignores the cookie if it cannot match (and, as such, load-balances as if it were a new request), but I wanted to confirm this.

 

Furthermore, on the response, does the F5 discard the timed out cookie and present the new one provided by the web server?

 

Also, are there any costs associated with setting the timeout value of these cookies to "Indefinite"?

 

I apologize if these questions are readily answered in the docs. I could not find these answers.

 

Thank you.

 

application delivery
BIG-IP
LTM

1 Reply

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  • Vijay_E's avatar
    Vijay_E
    Icon for Cirrus rankCirrus
    Mar 02, 2017

    My understanding:

     

    F5 will discard persistence key:value from its persistence table after timeout and hence, can't make a decision if the client presents the same cookie after timeout. New load balancing decision will be made with new cookie.

     

    Why do you want to set "indefinite" timeout ? If you are just looking for session persistence, you can utilize cookie insert. With indefinite timeout, I would expect uneven load balancing and depending on the number of connections, possible random loss in persistence if there are too many persistence table entries.

     

    In my opinion, when deciding on persistence timeout, your choice should be based on application requirements - how long should a client be persisted for the session to complete successfully.