Pod placement not equally done across multiple zones

Issue

• In some cases, pods gets scheduled in the same zone even if two identical zones with identical pods are available. We are using custom labels and have adjusted scheduler.json to implement anti-affinity based on these labels. The scheduler.json was extended with the following entry to achieve service-anti-affinity.

[...]
        {
            "argument": {
                "serviceAntiAffinity": {
                    "label": [ "datacenter" ]
                }
            },
            "name": "Datacenter",
            "weight": 10
        }
[...]