Measure Network Latency Statistics

You can configure ESXi hosts in your network to measure: pNIC to vNIC, vNIC to pNIC, vNIC to vNIC, and VTEP to VTEP network latency statistics.

Configuration is supported only using the NSX REST APIs. The steps in the following procedure list the NSX Policy APIs that you must run to configure the calculation of various network latency statistics. For a detailed information about the API schema, example request, example response, and error messages of all the APIs, you must read the NSX API Guide.

Prerequisites

Both vCenter-managed hosts and standalone ESXi hosts that you want to configure for measuring network latency statistics must be prepared for NSX. That is, NSX components must be installed on all the ESXi hosts in your network.

Procedure

1. To compute vNIC to vNIC, pNIC to vNIC, and vNIC to pNIC network latency statistics, do these steps:
   1. Create a group that contains host transport nodes as static members by using the following PUT API:

      PUT https://<nsx-mgr>/policy/api/v1/infra/domains/<domain-id>/groups/<group-id>

      In the request payload of this PUT API, specify the host transport node IDs in the expression parameter, as shown in the following example:

      Example PUT Request

      PUT https://<nsx-mgr>/policy/api/v1/infra/domains/default/groups/TNGroup
      
      {
          "expression": [
              {
                  "paths": [
                      "/infra/sites/default/enforcement-points/default/host-transport-nodes/4efdb573-fcce-43ff-8b35-dac583a86239"
                  ],
                  "resource_type": "PathExpression"
              }
          ],
          "extended_expression": [],
          "reference": false,
          "group_type": [],
          "resource_type": "Group",
          "id": "TNGroup",
          "display_name": "TNGroup",
          "path": "/infra/domains/default/groups/TNGroup",
          "relative_path": "TNGroup",
          "parent_path": "/infra/domains/default"
      }

      Observe that in this example request, the expression parameter contains a single host transport node ID.

   2. Create a latency profile with the following PUT API:

      PUT https://<nsx-mgr>/policy/api/v1/infra/latency-profiles/<profile-id>

      By default, vNIC to vNIC latency is measured for all the vNICs on the host transport node.

      In the request body of this API, configure the following information:

      • Activate or deactivate pNIC latency on the host. When it is activated, pNIC to vNIC and vNIC to pNIC latency are calculated for each vNIC on the host transport node.
      • Specify either the sampling rate or the sampling interval, but not both.
      • Specify the path to the group that you created in the earlier step.

      Example PUT Request

      PUT https://<nsx-mgr>/policy/api/v1/infra/latency-profiles/profile1
          {
            "sampling_rate": 100,
            "pnic_latency_enabled": false,
            "applied_to_group_path": "/infra/domains/default/groups/TNGroup"
          }

2. To measure VTEP to VTEP latency statistics, enable latency in the BFD health monitoring profile, which is a resource type in the transport zone profile. Run the following PUT API:

   PUT https://<nsx-mgr>/policy/api/v1/infra/transport-zone-profiles/<tz-profile-id>

What to do next

Export the statistics to an external collector for a deeper network insight and troubleshooting network-specific latency problems.