From 24cd1b529f35f106d323ebdd4df0203261824dcc Mon Sep 17 00:00:00 2001 From: Ciara Power Date: Thu, 30 Apr 2020 17:01:37 +0100 Subject: [PATCH] doc: update telemetry guides The existing documentation for Telemetry is updated, and further documentation is added. Signed-off-by: Ciara Power Reviewed-by: Keith Wiles --- doc/guides/howto/telemetry.rst | 110 ++++++++++------------ doc/guides/linux_gsg/eal_args.include.rst | 8 ++ doc/guides/linux_gsg/sys_reqs.rst | 2 - doc/guides/prog_guide/index.rst | 1 + doc/guides/prog_guide/telemetry_lib.rst | 58 ++++++++++++ doc/guides/rel_notes/release_20_05.rst | 15 +++ 6 files changed, 134 insertions(+), 60 deletions(-) create mode 100644 doc/guides/prog_guide/telemetry_lib.rst diff --git a/doc/guides/howto/telemetry.rst b/doc/guides/howto/telemetry.rst index cacc082161..b4a34ed674 100644 --- a/doc/guides/howto/telemetry.rst +++ b/doc/guides/howto/telemetry.rst @@ -1,86 +1,80 @@ .. SPDX-License-Identifier: BSD-3-Clause - Copyright(c) 2018 Intel Corporation. + Copyright(c) 2020 Intel Corporation. -DPDK Telemetry API User Guide -============================== -This document describes how the Data Plane Development Kit(DPDK) Telemetry API -is used for querying port statistics from incoming traffic. +DPDK Telemetry User Guide +========================= -Introduction ------------- +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. -The ``librte_telemetry`` provides the functionality so that users may query -metrics from incoming port traffic and global stats(application stats). -The application which initializes packet forwarding will act as the server, -sending metrics to the requesting application which acts as the client. +.. Note:: + This library is experimental and the output format may change in the future. -In DPDK, applications are used to initialize the ``telemetry``. To view incoming -traffic on featured ports, the application should be run first (ie. after ports -are configured). Once the application is running, the service assurance agent -(for example the collectd plugin) should be run to begin querying the API. -A client connects their Service Assurance application to the DPDK application -via a UNIX socket. Once a connection is established, a client can send JSON -messages to the DPDK application requesting metrics via another UNIX client. -This request is then handled and parsed if valid. The response is then -formatted in JSON and sent back to the requesting client. +Telemetry Interface +------------------- -Pre-requisites -~~~~~~~~~~~~~~ +The :doc:`../prog_guide/telemetry_lib` opens a socket with path +*/dpdk_telemetry.*. 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). -* Python >= 2.5 -* Jansson library for JSON serialization +Telemetry Initialization +------------------------ -Test Environment ----------------- +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`` offers a range of selftests that a client can run within -the DPDK application. +.. code-block:: console -Selftests are disabled by default. They can be enabled by setting the 'selftest' -variable to 1 in rte_telemetry_initial_accept(). + --telemetry -Note: this 'hardcoded' value is temporary. +A flag exists to disable Telemetry also. -Configuration -------------- +.. code-block:: console -Enable the telemetry API by modifying the following config option before -building DPDK:: + --no-telemetry - CONFIG_RTE_LIBRTE_TELEMETRY=y -Note: Meson will pick this up automatically if ``libjansson`` is available. +Running Telemetry +----------------- -Running the Application ------------------------ +The following steps show how to run an application with telemetry support, +and query information using the telemetry client python script. -The following steps demonstrate how to run the ``telemetry`` API to query all -statistics on all active ports, using the ``telemetry_client`` python script -to query. -Note: This guide assumes packet generation is applicable and the user is -testing with testpmd as a DPDK primary application to forward packets, although -any DPDK application is applicable. +#. Launch testpmd as the primary application with telemetry. -#. Launch testpmd as the primary application with ``telemetry``.:: + .. code-block:: console - ./app/testpmd --telemetry + ./app/dpdk-testpmd -#. Launch the ``telemetry`` python script with a client filepath.:: +#. Launch the telemetry client script. - python usertools/telemetry_client.py /var/run/some_client + .. code-block:: console - The client filepath is going to be used to setup our UNIX connection with the - DPDK primary application, in this case ``testpmd`` - This will initialize a menu where a client can proceed to recursively query - statistics, request statistics once or unregister the file_path, thus exiting - the menu. + python usertools/dpdk-telemetry.py -#. Send traffic to any or all available ports from a traffic generator. - Select a query option(recursive or singular polling or global stats). - The metrics will then be displayed on the client terminal in JSON format. +#. When connected, the script displays the following, waiting for user input. -#. Once finished, unregister the client using the menu command. + .. code-block:: console + + Connecting to /var/run/dpdk/rte/dpdk_telemetry.v2 + {"version": "DPDK 20.05.0-rc0", "pid": 60285, "max_output_len": 16384} + --> + +#. The user can now input commands to send across the socket, and receive the + response. + + .. code-block:: console + + --> / + {"/": ["/", "/eal/app_params", "/eal/params", "/ethdev/list", + "/ethdev/link_status", "/ethdev/xstats", "/help", "/info"]} + --> /ethdev/list + {"/ethdev/list": [0, 1]} diff --git a/doc/guides/linux_gsg/eal_args.include.rst b/doc/guides/linux_gsg/eal_args.include.rst index 711a246a08..0fe4457968 100644 --- a/doc/guides/linux_gsg/eal_args.include.rst +++ b/doc/guides/linux_gsg/eal_args.include.rst @@ -202,3 +202,11 @@ Other options * ``mbuf-pool-ops-name``: Pool ops name for mbuf to use. + +* ``--telemetry``: + + Enable telemetry (enabled by default). + +* ``--no-telemetry``: + + Disable telemetry. diff --git a/doc/guides/linux_gsg/sys_reqs.rst b/doc/guides/linux_gsg/sys_reqs.rst index 7c47ec04ce..a124656bcb 100644 --- a/doc/guides/linux_gsg/sys_reqs.rst +++ b/doc/guides/linux_gsg/sys_reqs.rst @@ -95,8 +95,6 @@ For libraries the additional dependencies include: * libarchive: for some unit tests using tar to get their resources. -* jansson: to compile and use the telemetry library. - * libelf: to compile and use the bpf library. For poll-mode drivers, the additional dependencies for each driver can be diff --git a/doc/guides/prog_guide/index.rst b/doc/guides/prog_guide/index.rst index f0ae3c1e7e..6f63f300af 100644 --- a/doc/guides/prog_guide/index.rst +++ b/doc/guides/prog_guide/index.rst @@ -56,6 +56,7 @@ Programmer's Guide packet_framework vhost_lib metrics_lib + telemetry_lib bpf_lib ipsec_lib graph_lib diff --git a/doc/guides/prog_guide/telemetry_lib.rst b/doc/guides/prog_guide/telemetry_lib.rst new file mode 100644 index 0000000000..d8f5856ee5 --- /dev/null +++ b/doc/guides/prog_guide/telemetry_lib.rst @@ -0,0 +1,58 @@ +.. SPDX-License-Identifier: BSD-3-Clause + Copyright(c) 2020 Intel Corporation. + +Telemetry Library +================= + +The Telemetry library provides an interface to retrieve information from a +variety of DPDK libraries. The library provides this information via socket +connection, taking requests from a connected client and replying with the JSON +response containing the requested telemetry information. + +Telemetry is enabled to run by default when running a DPDK application, and the +telemetry information from enabled libraries is made available. Libraries are +responsible for registering their own commands, and providing the callback +function that will format the library specific stats into the correct data +format, when requested. + + +Registering Commands +-------------------- + +Libraries and applications must register commands to make their information +available via the Telemetry library. This involves providing a string command +in the required format ("/library/command"), and the callback function that +will handle formatting the information when required. An example showing ethdev +commands being registered is shown below: + +.. code-block:: c + + rte_telemetry_register_cmd("/ethdev/list", handle_port_list); + rte_telemetry_register_cmd("/ethdev/xstats", handle_port_xstats); + + +Formatting JSON response +------------------------ + +The callback function provided by the library must format its telemetry +information in the required data format. The Telemetry library provides a data +utilities API to build up the response. For example, the ethdev library provides a +list of available ethdev ports in a formatted data response, constructed using the +following functions to build up the list: + +.. code-block:: c + + rte_tel_data_start_array(d, RTE_TEL_INT_VAL); + RTE_ETH_FOREACH_DEV(port_id) + rte_tel_data_add_array_int(d, port_id); + +The data structure is then formatted into a JSON response before sending. +The resulting response shows the port list data provided above by the handler +function in ethdev, placed in a JSON reply by telemetry: + +.. code-block:: console + + {"/ethdev/list": [0, 1]} + +For more information on the range of data functions available in the API, +please refer to the docs. diff --git a/doc/guides/rel_notes/release_20_05.rst b/doc/guides/rel_notes/release_20_05.rst index fe6c75e0eb..82df72c2b4 100644 --- a/doc/guides/rel_notes/release_20_05.rst +++ b/doc/guides/rel_notes/release_20_05.rst @@ -215,6 +215,21 @@ New Features * Added IPsec inbound load-distribution support for ipsec-secgw application using NIC load distribution feature(Flow Director). +* **Updated Telemetry Library.** + + The updated Telemetry library has many improvements on the original version + to make it more accessible and scalable: + + * It enables DPDK libraries and applications provide their own specific + telemetry information, rather than being limited to what could be reported + through the metrics library. + + * It is no longer dependent on the external Jansson library, which allows + Telemetry be enabled by default. + + * The socket handling has been simplified making it easier for clients to + connect and retrieve information. + * **Added rte_graph library.** Graph architecture abstracts the data processing functions as a ``node`` and -- 2.20.1