1.. SPDX-License-Identifier: BSD-3-Clause 2 Copyright(c) 2018 Intel Corporation. 3 4DPDK Telemetry API User Guide 5============================== 6 7This document describes how the Data Plane Development Kit(DPDK) Telemetry API 8is used for querying port statistics from incoming traffic. 9 10Introduction 11------------ 12 13The ``librte_telemetry`` provides the functionality so that users may query 14metrics from incoming port traffic. The application which initializes packet 15forwarding will act as the server, sending metrics to the requesting application 16which acts as the client. 17 18In DPDK, applications are used to initialize the ``telemetry``. To view incoming 19traffic on featured ports, the application should be run first (ie. after ports 20are configured). Once the application is running, the service assurance agent 21(for example the collectd plugin) should be run to begin querying the API. 22 23A client connects their Service Assurance application to the DPDK application 24via a UNIX socket. Once a connection is established, a client can send JSON 25messages to the DPDK application requesting metrics via another UNIX client. 26This request is then handled and parsed if valid. The response is then 27formatted in JSON and sent back to the requesting client. 28 29Pre-requisites 30~~~~~~~~~~~~~~ 31 32* Python >= 2.5 33 34* Jansson library for JSON serialization 35 36Test Environment 37---------------- 38 39``telemetry`` offers a range of selftests that a client can run within 40the DPDK application. 41 42Selftests are disabled by default. They can be enabled by setting the 'selftest' 43variable to 1 in rte_telemetry_initial_accept(). 44 45Note: this 'hardcoded' value is temporary. 46 47Configuration 48------------- 49 50Enable the telemetry API by modifying the following config option before 51building DPDK:: 52 53 CONFIG_RTE_LIBRTE_TELEMETRY=y 54 55Note: Meson will pick this up automatically if ``libjansson`` is available. 56 57Running the Application 58----------------------- 59 60The following steps demonstrate how to run the ``telemetry`` API to query all 61statistics on all active ports, using the ``telemetry_client`` python script 62to query. 63Note: This guide assumes packet generation is applicable and the user is 64testing with testpmd as a DPDK primary application to forward packets, although 65any DPDK application is applicable. 66 67#. Launch testpmd as the primary application with ``telemetry``.:: 68 69 ./app/testpmd --telemetry 70 71#. Launch the ``telemetry`` python script with a client filepath.:: 72 73 python usertools/telemetry_client.py /var/run/some_client 74 75 The client filepath is going to be used to setup our UNIX connection with the 76 DPDK primary application, in this case ``testpmd`` 77 This will initialize a menu where a client can proceed to recursively query 78 statistics, request statistics once or unregister the file_path, thus exiting 79 the menu. 80 81#. Send traffic to any or all available ports from a traffic generator. 82 Select a query option(recursive or singular polling). 83 The metrics will then be displayed on the client terminal in JSON format. 84 85#. Once finished, unregister the client using the menu command. 86