The REST API provides easy access to view the cluster topology, as shown in the following example

GET 'https://localhost:8090/api/v2/manager/cluster/topology'

The response will be wrapped inside a ClusterTopologyPayload and look something like the following:

{
    "payloadType": "ClusterTopologyPayload",
    "payloadVersion": "1",
    "payload": {
        "topology": "CLUSTERED_MASTER_SLAVE",
        "name": "usa",
        "services": [
            {
                "name": "east",
                "role": "slave",
                "datasources": [
                    {
                        "name": "db4",
                        "role": "relay"
                    },
                    {
                        "name": "db5",
                        "role": "slave"
                    },
                    {
                        "name": "db6",
                        "role": "slave"
                    }
                ]
            },
            {
                "name": "west",
                "role": "master",
                "datasources": [
                    {
                        "name": "db1",
                        "role": "master"
                    },
                    {
                        "name": "db2",
                        "role": "slave"
                    },
                    {
                        "name": "db3",
                        "role": "slave"
                    }
                ]
            }
        ],
        "routers": [
            {
                "name": "db1",
                "connections": {
                    "active": 0,
                    "created": 0
                }
            },
            {
                "name": "db2",
                "connections": {
                    "active": 0,
                    "created": 0
                }
            },
            {
                "name": "db3",
                "connections": {
                    "active": 0,
                    "created": 0
                }
            },
            {
                "name": "db4",
                "connections": {
                    "active": 0,
                    "created": 0
                }
            },
            {
                "name": "db5",
                "connections": {
                    "active": 0,
                    "created": 0
                }
            },
            {
                "name": "db6",
                "connections": {
                    "active": 0,
                    "created": 0
                }
            }
        ]
    }
}

It's also possible to omit the routers from the topology output, using the following call:

GET https://localhost:8090/api/v2/manager/cluster/topology?includeRouters=no