**To update a virtual node** The following ``update-virtual-node`` example uses a JSON input file to add a health check to a virtual node. :: aws appmesh update-virtual-node \ --cli-input-json file://update-virtual-node.json Contents of ``update-virtual-node.json``:: { "clientToken": "500", "meshName": "app1", "spec": { "listeners": [ { "healthCheck": { "healthyThreshold": 5, "intervalMillis": 10000, "path": "/", "port": 80, "protocol": "http", "timeoutMillis": 3000, "unhealthyThreshold": 3 }, "portMapping": { "port": 80, "protocol": "http" } } ], "serviceDiscovery": { "dns": { "hostname": "serviceBv1.svc.cluster.local" } } }, "virtualNodeName": "vnServiceBv1" } Output:: { "virtualNode": { "meshName": "app1", "metadata": { "arn": "arn:aws:appmesh:us-east-1:123456789012:mesh/app1/virtualNode/vnServiceBv1", "createdAt": 1563810019.874, "lastUpdatedAt": 1563819234.825, "uid": "a1b2c3d4-5678-90ab-cdef-11111EXAMPLE", "version": 2 }, "spec": { "listeners": [ { "healthCheck": { "healthyThreshold": 5, "intervalMillis": 10000, "path": "/", "port": 80, "protocol": "http", "timeoutMillis": 3000, "unhealthyThreshold": 3 }, "portMapping": { "port": 80, "protocol": "http" } } ], "serviceDiscovery": { "dns": { "hostname": "serviceBv1.svc.cluster.local" } } }, "status": { "status": "ACTIVE" }, "virtualNodeName": "vnServiceBv1" } } For more information, see `Virtual Nodes <https://docs.aws.amazon.com/app-mesh/latest/userguide/virtual_nodes.html>`__ in the *AWS App Mesh User Guide*.