ACE: sticky serverfarm

Question

Dear all,
I do have a question about the configuration option of a sticky serverfarm. There is an option to timeout active conns. Originally my thinking was that this option changes the sticky behaviour to a session timeout instead an idle timeout. While testing this seems to be not correct
sticky http-cookie myCookie myStickyServerfarm
timeout 10
timeout activeconns
replicate sticky
serverfarm myServerfarm backup mySorryfarm
The manual explains it like this:
Configuring a Cookie Sticky Timeout
The sticky timeout specifies the period of time that the ACE keeps the HTTP cookie sticky information for a client connection in the sticky table after the latest client connection terminates. The ACE resets the sticky timer for a specific sticky-table entry each time that the module opens a new connection that matches that entry.
This brings me to the question, what is this option used for. The only diffrence I can see is, that there is a http connection which is open for longer than the timeout value (here 10min) will be kicked out and in the meantime this sticky-entry isn't used (otherwise the idle time would be reset).
Are there any other explanations what this feature can do?
best regards
Oliver

Answer 1

Hi Oliver,
I'm afraid the official documentation is not very clear on this section.
The sticky timeout doesn't count since the moment that the last connection is closed, but since it's established. However, by default it will not remove the sticky entry as long as there are connections still active. This is what can be tuned with the "timeout activeconns".
When the "timeout activeconns" option is present, the ACE will remove the sticky entry as soon as the timer is reached, regardless of whether there are active connections or not.
I hope this answers your question, but if you want some further clarification, let me know.
Regards
Daniel