How to disable sticky sessions in Openshift3

Question

If you scale up a Pod in Openshift3, all requests coming from the same client IP address are sent to container which has the session associated.

Is there any config

Answer 1

oc set env dc/router ROUTER_TCP_BALANCE_SCHEME=roundrobin will change the load balancing algorithm haproxy uses for routes it just passes through (default is source). ROUTER_LOAD_BALANCE_ALGORITHM will change it for routes where it terminates TLS (default us leastconn).

More info on changing the internals of how haproxy works in the OCP 3.5 docs .

Answer 2

For posterity, and since I had the same problem, I want to document the solution I used from Graham Dumpleton's excellent comment.

As it turns out, a cookie is set during the first request that redirects subsequent requests to the same back-end. To disable this behavior on a per-route basis:

oc annotate routes myroute haproxy.router.openshift.io/disable_cookies='true'

This prevents the cookie from being set and allows the balance algorithm to select the appropriate back-end for subsequent requests from the same client. To change the balance algorithm:

oc annotate routes myroute haproxy.router.openshift.io/balance='roundrobin'

With these two annotations set, requests from the same client IP address are sent to each back-end in turn, instead of the same back-end over and over.