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MM_F_147944
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May 31, 2017

Action on service Down : Reselect

we have configured Standard type Virtual server with HTTP profile and have enabled Persistence profile Source Add, Pool is load balanced by Least connection(member)

 

we are facing issue regarding client was sending to the the partition with become down so to tackle this we selected Re-select Option on Active Service Down.

 

With this Option we are receiving another complain of automatic logout and error message 500.

 

Application is running on TCP.

 

2 Replies

  • You can try to use "Reject" for "Active Service Down".

     

    Reject: Specifies that, if there are no pool members available, the system resets and clears the active connections from the connection table and sends a reset (RST) or Internet Control Message Protocol (ICMP) message. If there are pool members available, the system resets and clears the active connections, but sends newly arriving connections to the available pool member and does not send RST or ICMP messages.

     

    Reselect: Specifies that the system manages established client connections by moving them to an alternative pool member when monitors mark the original pool member down.

     

  • Hi,

     

    Reselect will never work with HTTP, it is just silently starting to send TCP packets to new member without performing 3WHS - so new member will see TCP packets for which it has no TCP connection established - usual server response will be RST.

     

    So instead of RST send by BIG-IP (when Reject is used) RST is generated by backend server and then passed to client by BIG-IP.

     

    I am not sure what do you mean by "partition/ pool member goes down" - do you mean that pool member is marked down by monitor but traffic is still directed to this member?

     

    Piotr