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Puli's avatar
Puli
Icon for Nimbostratus rankNimbostratus
Sep 22, 2011

Requests intermittently being re-directed to HTTP Profile

We have a situation where intermittently about 4-5 click sometimes that are re-direct to the url we configured in the HTTP Profile.

 

The HTTP Profile url is intended to server as fallback url when both pool members are down.

 

 

We monitored the logs, dont see that the pool members are are not marked down by monitors.

 

 

The virtual server uses an iRule which diverts traffic based on HTTP::URI to two differrent pools.

 

 

We migrated from BigIP 9.4.8 to Bigip 10.2 and started noticing this behaviour.

 

 

Any ideas why this might be happening? I cant seem to track down when a request going to the http profile, it is possible from the iRule via log commands ?

 

 

Appreciate any suggestions.

 

thanks,

 

Puli.

 

application delivery
dev
devops
iRules

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  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Sep 22, 2011
    Hi Puli,

     

     

    The fallback host will be used if a load balancing attempt fails--not only if the whole pool is marked down. You could try capturing a tcpdump to see what is happening on the serverside when the HTTP profile fallback host is used.

     

     

    If you want to change the fallback behavior to only send a redirect if the whole pool is marked down, you could use the example from this solution:

     

     

    sol6510: Change in Behavior: The Fallback Host is now used when a connection to a node fails

     

    http://support.f5.com/kb/en-us/solutions/public/6000/500/sol6510.html

     

     

    Aaron
  • Puli's avatar
    Puli
    Icon for Nimbostratus rankNimbostratus
    Sep 23, 2011
    Thanks Aaron,

     

    we worked with bigip admin ran a trace, he was'nt able to identify why lbr fails intermittenly.

     

    Any tips to narrow it down to why LBR failing for a request

     

    We ran Live http headers during test and the request are similar to then the page is server and when a request is sent to fallback host.

     

    We also have client side ssl termination set, with onconnect_ip profile with network 255.255.255.255.

     

     

    appreciate any input.

     

    thanks for you time.

     

    Puli.

     

  • Michael_Yates's avatar
    Michael_Yates
    Icon for Nimbostratus rankNimbostratus
    Sep 23, 2011
    Hi Puli,

     

     

    You wouldn't happen to have the "Fallback on Error Codes" configured would you?

     

     

    If not then I would suggest using the example iRule in the Solution that hoolio provided, disabling the Fallback in the HTTP Profile, and retesting with additional logging configured in the iRule to see if you get the same behavior.

     

     

    If you do not then you could you could open up a case with F5 to explore the possibility of a bug in the HTTP Profile. (If you do open a case can you post case number so that we can track the results?)