"plugins": {
        "traffic-split": {
            "rules": [
                {
                    "match": [
                        {
                            "vars": [
                                ["arg_name","==","test"]
                            ]
                        }
                    ],
                    "weighted_upstreams": [
                        {
                            "upstream": {
                                "name": "upstream_A",
                                "type": "roundrobin",
                                "nodes": {
                                    "127.0.0.1:1981":10
                                }
                            }
                        }
                    ]
                }
            ]
        }
    }