Forum Discussion

cmard_195831's avatar
cmard_195831
Icon for Nimbostratus rankNimbostratus
Nov 20, 2015

explain what the irule is exactly doing

Hello,

 

I have an irule on the system and I need to know exactly what is doing. It is executed in the menu: virtual servers (choice of VS) -> Resources irule definition (acting on pool members)

 

when CLIENT_ACCEPTED { persist uie 1 }

 

3 Replies

  • The irule is doing persistence based on a static record.. 1

     

    The first connection will select pool member and create a persistence record... every other connections will be redirecting to the same pool member until persistence record timeout.

     

  • Thank you Stanislas,

     

    My next question is which parameters in F5 (either from the command line or GUI affect this persistance record timeout.

     

    In our case we have 2 x tomcat servers and only one is the one "in persistance" no load balancing. When the F5 detects that the tomcat is down (port 9090 for us), the F5 starts sending packets to the other tomcat, which was in stand-by mode. The fact is that there is a period of time (30-40 seconds) that the F5 is sending packets to BOTH tomcats and thus there is a mess. The fact is that the F5 does not seem to make a "sudden death" situation where if A is active, I send packets only to A and when there is a switch over then packets are sent only to B. There is a gray period on this. I do not know by how much the above irule is helping.

     

    Awaiting for any suggestions. Many thanks

     

  • I did not find the default timeout. it may be 30 seconds as you saw.

    you can force timeout time with

    when CLIENT_ACCEPTED { persist uie 1 300 }
    . 300 is the timeout in seconds.

    if you want to configure HA, the solution is to use priority group activation in pool configuration.