Bug 2017708

Prior to 4.8 the default balancing algorithm was "leastconn". The default was changed to "random" in OpenShift 4.8.0 for non-passthrough routes. Switching to "random" significantly increases memory consumption for each and every HAProxy process and the cumulative memory usage can be significant particularly if you have a lot of websocket connections. To mitigate this significant memory consumption the default balancing algorithm has now been reverted to "leastconn" for OpenShift 4.8 and 4.9. Once we have a solution that does not incur such significant memory requirements we would default to "random" again, but that would be for a future OpenShift release (i.e., 4.10 or later). You can check the default setting via: $ oc get deployment -n openshift-ingress router-default -o yaml | grep -A 2 ROUTER_LOAD_BALANCE_ALGORITHM - name: ROUTER_LOAD_BALANCE_ALGORITHM value: leastconn The "random" option is still available but each and every route that would benefit from this algorithmic choice will now have to explicitly request that by setting the following annotation on a per-route basis: $ oc annotate -n <NAMESPACE> route/<ROUTE-NAME> "haproxy.router.openshift.io/balance=random"