On 9.2.2012, at 10.36, Andy YB Hu wrote:
I just tried out the Director. One question is about the re-redirection. I know director will redirect all the simultaneous requests from the same user to only a single server at the same time. The question is how to manage the time period after last connection to re-decide to redirect which machine? director_user_expire? Look like not.
I did one test, set director_user_expire = 1 min, then keep sending requests to the director in 2 min interval, the result is it keeps redirect to the same back end server.
In normal operation the user is always redirected to the same server. http://blog.dovecot.org/2010/05/new-director-service-in-v20-for-nfs.html has some more details.
If you have enough connections, it shouldn't matter that the connections aren't constantly going to random backends. In practice they get distributed well enough.