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diff --git a/docs/requirements/03-dpdk.rst b/docs/requirements/03-dpdk.rst deleted file mode 100644 index ad7c8c78..00000000 --- a/docs/requirements/03-dpdk.rst +++ /dev/null @@ -1,170 +0,0 @@ -.. This work is licensed under a Creative Commons Attribution 4.0 International License. -.. http://creativecommons.org/licenses/by/4.0 -.. (c) OPNFV, Intel Corporation and others. - -DPDK Enhancements -================== -This section will discuss the Barometer features that were integrated with DPDK. - -Measuring Telco Traffic and Performance KPIs --------------------------------------------- -This section will discuss the Barometer features that enable Measuring Telco Traffic -and Performance KPIs. - -.. Figure:: stats_and_timestamps.png - - Measuring Telco Traffic and Performance KPIs - -* The very first thing Barometer enabled was a call-back API in DPDK and an - associated application that used the API to demonstrate how to timestamp - packets and measure packet latency in DPDK (the sample app is called - rxtx_callbacks). This was upstreamed to DPDK 2.0 and is represented by - the interfaces 1 and 2 in Figure 1.2. - -* The second thing Barometer implemented in DPDK is the extended NIC statistics API, - which exposes NIC stats including error stats to the DPDK user by reading the - registers on the NIC. This is represented by interface 3 in Figure 1.2. - - * For DPDK 2.1 this API was only implemented for the ixgbe (10Gb) NIC driver, - in association with a sample application that runs as a DPDK secondary - process and retrieves the extended NIC stats. - - * For DPDK 2.2 the API was implemented for igb, i40e and all the Virtual - Functions (VFs) for all drivers. - - * For DPDK 16.07 the API migrated from using string value pairs to using id - value pairs, improving the overall performance of the API. - -Monitoring DPDK interfaces --------------------------- -With the features Barometer enabled in DPDK to enable measuring Telco traffic and -performance KPIs, we can now retrieve NIC statistics including error stats and -relay them to a DPDK user. The next step is to enable monitoring of the DPDK -interfaces based on the stats that we are retrieving from the NICs, by relaying -the information to a higher level Fault Management entity. To enable this Barometer -has been enabling a number of plugins for collectd. - -DPDK Keep Alive description ---------------------------- -SFQM aims to enable fault detection within DPDK, the very first feature to -meet this goal is the DPDK Keep Alive Sample app that is part of DPDK 2.2. - -DPDK Keep Alive or KA is a sample application that acts as a heartbeat/watchdog -for DPDK packet processing cores, to detect application thread failure. The -application supports the detection of ‘failed’ DPDK cores and notification to a -HA/SA middleware. The purpose is to detect Packet Processing Core fails (e.g. -infinite loop) and ensure the failure of the core does not result in a fault -that is not detectable by a management entity. - -.. Figure:: dpdk_ka.png - - DPDK Keep Alive Sample Application - -Essentially the app demonstrates how to detect 'silent outages' on DPDK packet -processing cores. The application can be decomposed into two specific parts: -detection and notification. - -* The detection period is programmable/configurable but defaults to 5ms if no - timeout is specified. -* The Notification support is enabled by simply having a hook function that where this - can be 'call back support' for a fault management application with a compliant - heartbeat mechanism. - -DPDK Keep Alive Sample App Internals -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -This section provides some explanation of the The Keep-Alive/'Liveliness' -conceptual scheme as well as the DPDK Keep Alive App. The initialization and -run-time paths are very similar to those of the L2 forwarding application (see -`L2 Forwarding Sample Application (in Real and Virtualized Environments)`_ for more -information). - -There are two types of cores: a Keep Alive Monitor Agent Core (master DPDK core) -and Worker cores (Tx/Rx/Forwarding cores). The Keep Alive Monitor Agent Core -will supervise worker cores and report any failure (2 successive missed pings). -The Keep-Alive/'Liveliness' conceptual scheme is: - -* DPDK worker cores mark their liveliness as they forward traffic. -* A Keep Alive Monitor Agent Core runs a function every N Milliseconds to - inspect worker core liveliness. -* If keep-alive agent detects time-outs, it notifies the fault management - entity through a call-back function. - -**Note:** Only the worker cores state is monitored. There is no mechanism or agent -to monitor the Keep Alive Monitor Agent Core. - -DPDK Keep Alive Sample App Code Internals -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -The following section provides some explanation of the code aspects that are -specific to the Keep Alive sample application. - -The heartbeat functionality is initialized with a struct rte_heartbeat and the -callback function to invoke in the case of a timeout. - -.. code:: c - - rte_global_keepalive_info = rte_keepalive_create(&dead_core, NULL); - if (rte_global_hbeat_info == NULL) - rte_exit(EXIT_FAILURE, "keepalive_create() failed"); - -The function that issues the pings hbeat_dispatch_pings() is configured to run -every check_period milliseconds. - -.. code:: c - - if (rte_timer_reset(&hb_timer, - (check_period * rte_get_timer_hz()) / 1000, - PERIODICAL, - rte_lcore_id(), - &hbeat_dispatch_pings, rte_global_keepalive_info - ) != 0 ) - rte_exit(EXIT_FAILURE, "Keepalive setup failure.\n"); - -The rest of the initialization and run-time path follows the same paths as the -the L2 forwarding application. The only addition to the main processing loop is -the mark alive functionality and the example random failures. - -.. code:: c - - rte_keepalive_mark_alive(&rte_global_hbeat_info); - cur_tsc = rte_rdtsc(); - - /* Die randomly within 7 secs for demo purposes.. */ - if (cur_tsc - tsc_initial > tsc_lifetime) - break; - -The rte_keepalive_mark_alive() function simply sets the core state to alive. - -.. code:: c - - static inline void - rte_keepalive_mark_alive(struct rte_heartbeat *keepcfg) - { - keepcfg->state_flags[rte_lcore_id()] = 1; - } - -Keep Alive Monitor Agent Core Monitoring Options -The application can run on either a host or a guest. As such there are a number -of options for monitoring the Keep Alive Monitor Agent Core through a Local -Agent on the compute node: - - ====================== ========== ============= - Application Location DPDK KA LOCAL AGENT - ====================== ========== ============= - HOST X HOST/GUEST - GUEST X HOST/GUEST - ====================== ========== ============= - - -For the first implementation of a Local Agent SFQM will enable: - - ====================== ========== ============= - Application Location DPDK KA LOCAL AGENT - ====================== ========== ============= - HOST X HOST - ====================== ========== ============= - -Through extending the dpdkstat plugin for collectd with KA functionality, and -integrating the extended plugin with Monasca for high performing, resilient, -and scalable fault detection. - -.. _L2 Forwarding Sample Application (in Real and Virtualized Environments): http://dpdk.org/doc/guides/sample_app_ug/l2_forward_real_virtual.html |