View the Topology of Services in a Global Namespace or a Cluster

You can view the topology of the services in a global namespace or a cluster as a chart. You can use the topology graph to understand the service dependencies and determine the health of the services.

Tanzu Service Mesh generates a topology graph view dynamically by observing the traffic that is flowing between the services in a global namespace or a cluster. The topology graph visualizes the communication patterns between the services and helps you gain insights into the service dependencies. The topology graph also shows the key metrics for the services, thus helping you determine the health of the services. The following key health metrics are displayed:

• The service's incoming requests per second (RPS) metric

• The error rate, that is, the percentage of failed requests to the service

• The 99th percentile latency of requests processed by the service

Prerequisites

• Access the Tanzu Service Mesh Console.

• To view the topology of services in a cluster, onboard the cluster to Tanzu Service Mesh.

• To view the topology of services in a global namespace, create a global namespace and map the services to the global namespace.

Procedure

1. On the Home page, perform one of the following steps.

   Option	Description
   To view the service topology in a global namespace	Click the GNS Overview tab. On the card for the global namespace that you want, click the global namespace name or the topology thumbnail.
   To view the service topology in a cluster	Click the Cluster Overview tab. On the card for the cluster that you want, click the cluster name or the topology thumbnail.

   Note:

   • You can also click the three vertical dots in the upper-right corner of the card and then click Browse Global Namespace Topology or Browse Cluster Topology.

   • You can also view the topology graph from the Global Namespaces or Clusters page. To the left of the global namespace or cluster name, click the three vertical dots and then click Browse Global Namespace Topology or Browse Cluster Topology. To access the Global Namespaces page, in the navigation pane on the left, select Inventory > Global Namespaces. To access the Clusters page, select Inventory > Infrastructure and then click the Clusters tab.

   The Topology Browser window displays the topology graph for the services in the global namespace or the cluster. The nodes in the graph represent the services, and the lines represent the incoming and outgoing connections between the services based on observed traffic.

   For a global namespace that is mapped to services from multiple clusters, the service topology in each cluster is displayed inside a colored rectangle, and the cross-cluster service connections are shown. The color legend at the top of the window identifies the clusters by name.

   Tip:

   • To focus on the incoming and outgoing connections of a specific service and hide the other connections, click the service node. To return to the full graph view, in the upper-left corner of the window, click Back.

   • To view the incoming and outgoing connections of a service on the Service Dependencies tab of the service details page, click the service name under the service node.

   • You can also reposition the service nodes and entire cluster rectangles in the graph. To reposition a service node, drag it to a new position. To reposition an entire cluster rectangle, click anywhere in the box and drag it to a new position. Tanzu Service Mesh automatically saves the new positions to your user preferences and retrieves them on any computer and device that you use.

   The key health metrics are displayed for each service under its node in the graph. The RPS metric between two services is overlaid on the connection between the services. The total metric values for each cluster are displayed at the top of the cluster rectangle. To show only the metrics that you want in the graph, click Graph Settings and select the metrics to show under the service nodes and at the top of the cluster rectangles. You can select a maximum of four metrics to be displayed.

   To show or hide the RPS metric on the service connections, under Service Connections, select or deselect Show RPS.

   Note:

   When you point to a service name in the graph, the key health metrics and details are displayed for that service in a card. The metric values in the card are displayed for the last 5 minutes.

   The chart reflects the state of communication between the services for the time frame selected in the Metric Time Range drop-down menu in the upper-right corner of the window (for example, Last 30 minutes or Last 7 days). To display the topology chart for a different time frame, select the time frame from the Metric Time Range drop-down menu.

   Note:

   • Tanzu Service Mesh collects and retains metrics data from the last 7 days. You can select an option from the Metric Time Range drop-down menu to see data from the last 5 minutes to up to the last 7 days. This is a global setting and applies not only to the data on the Home page but also to the data, graphs, and charts on the other pages in the Tanzu Service Mesh Console UI.

   • If two services don't communicate during the time frame selected in the Metric Time Range drop-down menu, no line is shown between those services in the graph.

   • To view the services that don't have connections with other services in the global namespace or cluster based on observed traffic, click Unconnected Services at the bottom of the window.

2. (Optional) To perform the following actions from the Topology Browser window, click these options and buttons in the window.

   Option or Button	Action
   Open GNS Details Page or Open Cluster Details Page	Open the details page for the global namespace or cluster.
   Show drop-down menu in the upper-left corner	View all the services in the cluster or the services in a specific namespace by selecting All Services or the name of the namespace.
   Show Service Versions or Hide Service Versions	Show or hide the versions of each service inside the service node.
   Edit Configuration	Edit the global namespace configuration in the Edit Global Namespace window or edit the cluster details in the Edit Cluster window.
   More Actions	Click this button and then Delete Global Namespace or Remove Cluster to delete the global namespace or remove the cluster from Tanzu Service Mesh.
   	Download the information about the service connnections shown in the topology graph to a comma-separated values (CSV) file to make this information accessible to users with visual impairments. The header of the CSV file contains the name of your Tanzu Service Mesh organization, the name of the global namespace or of the cluster, and the time range applied to the topology graph. The file also contains the following columns: Services. Lists the services in the global namespace or the cluster. If you selected Show Service Versions in the Topology Browser window, this column has a heading of Service Versions and lists the services in the format service, service version, cluster. Source Service Versions (incoming Requests). Contains the source services, that is, the services from which each service in the Services column receives traffic. The source services are listed in the format (service A, cluster), (service B, cluster). If you selected Show Service Versions in the Topology Browser window, the source services are listed in the format (service A, service version A version, cluster), (service B, service B version, cluster). Destination Service Versions (Outgoing Requests). Contains the destination services, that is, the services to which each service in the Services column sends traffic. The destination services are listed in the format (service A, cluster), (service B, cluster). If you selected Show Service Versions in the Topology Browser window, the destination services are listed in the format (service A, service version A version, cluster), (service B, service B version, cluster). Note: If you downloaded the service topology information for a cluster, the columns in the CSV file do not contain the cluster name as the last value. You can also download the service topology information to a CSV file from a global namespace card or a cluster card on the GNS View tab or the Cluster View tab of the Home page. In the upper-right corner of the card, click the three vertical dots and then click Download Topology as CSV. If not traffic is observed between the services in a global namespace or a cluster during a selected time frame, the service topology information is unavailable for download. In this case, the Download Topology button () in the Topology Browser window and the Download Topology as CSV option on the global namespace or cluster card are unavailable.
   	Resize the topology graph so that it fits in the window.
   	Zoom out on the graph.
   	Zoom in on the graph.

3. To close the Topology Browser window, in the upper-left corner, click or press Escape.