10. DPDK Telemetry User Guide

The Telemetry library provides users with the ability to query DPDK for telemetry information, currently including information such as ethdev stats, ethdev port list, and eal parameters.

Note

This library is experimental and the output format may change in the future.

10.1. Telemetry Interface

The Telemetry Library opens a socket with path <runtime_directory>/dpdk_telemetry.<version>. The version represents the telemetry version, the latest is v2. For example, a client would connect to a socket with path /var/run/dpdk/*/dpdk_telemetry.v2 (when the primary process is run by a root user).

10.2. Telemetry Initialization

The library is enabled by default, however an EAL flag to enable the library exists, to provide backward compatibility for the previous telemetry library interface:

--telemetry

A flag exists to disable Telemetry also:

--no-telemetry

10.3. Running Telemetry

The following steps show how to run an application with telemetry support, and query information using the telemetry client python script.

1. Launch testpmd as the primary application with telemetry:

   ./app/dpdk-testpmd
   

2. Launch the telemetry client script:

   python usertools/dpdk-telemetry.py
   

3. When connected, the script displays the following, waiting for user input:

   Connecting to /var/run/dpdk/rte/dpdk_telemetry.v2
   {"version": "DPDK 20.05.0-rc2", "pid": 60285, "max_output_len": 16384}
   -->
   

4. The user can now input commands to send across the socket, and receive the response. Some available commands are shown below.

   • List all commands:

     --> /
     {"/": ["/", "/eal/app_params", "/eal/params", "/ethdev/list",
     "/ethdev/link_status", "/ethdev/xstats", "/help", "/info"]}
     

   • Get the list of ethdev ports:

     --> /ethdev/list
     {"/ethdev/list": [0, 1]}
     

   Note

   For commands that expect a parameter, use ”,” to separate the command and parameter. See examples below.

   • Get extended statistics for an ethdev port:

     --> /ethdev/xstats,0
     {"/ethdev/xstats": {"rx_good_packets": 0, "tx_good_packets": 0,
     "rx_good_bytes": 0, "tx_good_bytes": 0, "rx_missed_errors": 0,
     ...
     "tx_priority7_xon_to_xoff_packets": 0}}
     

   • Get the help text for a command. This will indicate what parameters are required. Pass the command as a parameter:

     --> /help,/ethdev/xstats
     {"/help": {"/ethdev/xstats": "Returns the extended stats for a port.
     Parameters: int port_id"}}