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diff --git a/docs/userguide/collectd.userguide.rst b/docs/userguide/collectd.userguide.rst new file mode 100644 index 00000000..0755fdf5 --- /dev/null +++ b/docs/userguide/collectd.userguide.rst @@ -0,0 +1,202 @@ +.. 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. + +collectd plugins description +============================ +The SFQM collectd plugins enable the ability to monitor DPDK interfaces by +exposing stats and the relevant events to higher level telemetry and fault +management applications. The following sections will discuss the SFQM features +in detail. + +Measuring Telco Traffic and Performance KPIs +-------------------------------------------- +This section will discuss the SFQM features that enable Measuring Telco Traffic +and Performance KPIs. + +.. Figure:: stats_and_timestamps.png + + Measuring Telco Traffic and Performance KPIs + +* The very first thing SFQM 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 SFQM 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 SFQM 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 SFQM +has been enabling a number of plugins for collectd. + +collectd +~~~~~~~~ +collectd is a daemon which collects system performance statistics periodically +and provides a variety of mechanisms to publish the collected metrics. It +supports more than 90 different input and output plugins. Input plugins retrieve +metrics and publish them to the collectd deamon, while output plugins publish +the data they receive to an end point. collectd also has infrastructure to +support thresholding and notification. + +collectd statistics and Notifications +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Within collectd notifications and performance data are dispatched in the same +way. There are producer plugins (plugins that create notifications/metrics), +and consumer plugins (plugins that receive notifications/metrics and do +something with them). + +Statistics in collectd consist of a value list. A value list includes: + +* Values, can be one of: + + * Derive: used for values where a change in the value since it's last been + read is of interest. Can be used to calculate and store a rate. + + * Counter: similar to derive values, but take the possibility of a counter + wrap around into consideration. + + * Gauge: used for values that are stored as is. + + * Absolute: used for counters that are reset after reading. + +* Value length: the number of values in the data set. + +* Time: timestamp at which the value was collected. + +* Interval: interval at which to expect a new value. + +* Host: used to identify the host. + +* Plugin: used to identify the plugin. + +* Plugin instance (optional): used to group a set of values together. For e.g. + values belonging to a DPDK interface. + +* Type: unit used to measure a value. In other words used to refer to a data + set. + +* Type instance (optional): used to distinguish between values that have an + identical type. + +* meta data: an opaque data structure that enables the passing of additional + information about a value list. "Meta data in the global cache can be used to + store arbitrary information about an identifier" [7]. + +Host, plugin, plugin instance, type and type instance uniquely identify a +collectd value. + +Values lists are often accompanied by data sets that describe the values in more +detail. Data sets consist of: + +* A type: a name which uniquely identifies a data set. + +* One or more data sources (entries in a data set) which include: + + * The name of the data source. If there is only a single data source this is + set to "value". + + * The type of the data source, one of: counter, gauge, absolute or derive. + + * A min and a max value. + +Types in collectd are defined in types.db. Examples of types in types.db: + +.. code-block:: console + + bitrate value:GAUGE:0:4294967295 + counter value:COUNTER:U:U + if_octets rx:COUNTER:0:4294967295, tx:COUNTER:0:4294967295 + +In the example above if_octets has two data sources: tx and rx. + +Notifications in collectd are generic messages containing: + +* An associated severity, which can be one of OKAY, WARNING, and FAILURE. + +* A time. + +* A Message + +* A host. + +* A plugin. + +* A plugin instance (optional). + +* A type. + +* A types instance (optional). + +* Meta-data. + +collectd plugins +---------------- +SFQM has enabled three collectd plugins to date: + +* `dpdkstat plugin`_: A read plugin that retrieve stats from the DPDK extended + NIC stats API. + +* `ceilometer plugin`_: A write plugin that pushes the retrieved stats to + Ceilometer. It's capable of pushing any stats read through collectd to + Ceilometer, not just the DPDK stats. + +* `hugepages plugin`_: A read plugin that retrieves the number of available + and free hugepages on a platform as well as what is available in terms of + hugepages per socket. + +Other plugins in progress: + +* dpdkevents: A read plugin that retrieves DPDK link status and DPDK + forwarding cores liveliness status (DPDK Keep Alive). + +* Open vSwitch stats Plugin: A read plugin that retrieve flow and interface + stats from OVS. + +* Open vSwitch events Plugin: A read plugin that retrieves events from OVS. + + +Monitoring Interfaces and Openstack Support +------------------------------------------- +.. Figure:: monitoring_interfaces.png + + Monitoring Interfaces and Openstack Support + +The figure above shows the DPDK L2 forwarding application running on a compute +node, sending and receiving traffic. collectd is also running on this compute +node retrieving the stats periodically from DPDK through the dpdkstat plugin +and publishing the retrieved stats to Ceilometer through the ceilometer plugin. + +To see this demo in action please checkout: `SFQM OPNFV Summit demo`_ + +References +---------- +[1] https://collectd.org/wiki/index.php/Naming_schema +[2] https://github.com/collectd/collectd/blob/master/src/daemon/plugin.h +[3] https://collectd.org/wiki/index.php/Value_list_t +[4] https://collectd.org/wiki/index.php/Data_set +[5] https://collectd.org/documentation/manpages/types.db.5.shtml +[6] https://collectd.org/wiki/index.php/Data_source +[7] https://collectd.org/wiki/index.php/Meta_Data_Interface + +.. _SFQM OPNFV Summit demo: https://prezi.com/kjv6o8ixs6se/software-fastpath-service-quality-metrics-demo/ +.. _dpdkstat plugin: https://github.com/maryamtahhan/collectd-with-DPDK/tree/dpdkstat +.. _ceilometer plugin: https://github.com/openstack/collectd-ceilometer-plugin/tree/stable/mitaka +.. _hugepages plugin: https://github.com/maryamtahhan/collectd-with-DPDK/tree/hugepages |