json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "additionalItems": false,
      "description": "IP address/port for primary/backup server pair",
      "items": {
          "properties": {
              "address": {
                  "type": "string"
              },
              "port": {
                  "maximum": 65535,
                  "minimum": 0,
                  "type": "integer"
              }
          },
          "required": [
              "address",
              "port"
          ],
          "type": "object"
      },
      "maxItems": 2,
      "minItems": 2,
      "title": "Primary and Backup Servers",
      "type": "array",
      "_uniqueItems": true
  }