We have HAProxy successfully performing sticky session routing based on a value
in the request querystring with the following configuration command.
balance url_param userId
This works great and if application server A fails, then you can see subsequent
requests being routed to a new target server B which is the desired behaviour.
However, if application server A comes back online we see the requests for
certain users once again being routed there which causes the users to
experience 2 dropped sessions instead of just 1.
Is there any way to tell HAProxy to pin requests for active sessions to server
B for some minimum timeout period so that requests only return to Server A once
those user sessions have expired?
Any help on this much appreciated.
Duncan Mason
