.. _feature-userguide:

.. This work is licensed under a Creative Commons Attribution 4.0 International License.
.. http://creativecommons.org/licenses/by/4.0
.. (c) Anuket and others

===========================
Anuket Barometer User Guide
===========================

Barometer collectd plugins description
---------------------------------------
.. Describe the specific features and how it is realised in the scenario in a brief manner
.. to ensure the user understand the context for the user guide instructions to follow.

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.

Barometer has enabled the following collectd plugins:

* *dpdk_telemetry plugin*:  A read plugin to collect dpdk interface stats and
  application or global stats from dpdk telemetry library. The ``dpdk_telemetry``
  plugin provides both DPDK NIC Stats and DPDK application stats.
  This plugin doesn't deal with dpdk events.
  The mimimum dpdk version required to use this plugin is 19.08.

.. note::
  The ``dpdk_telemetry`` plugin should only be used if your dpdk application
  doesn't already have more relevant metrics available (e.g.ovs_stats).

* `gnocchi plugin`_: A write plugin that pushes the retrieved stats to
  Gnocchi. It's capable of pushing any stats read through collectd to
  Gnocchi, not just the DPDK stats.

* `aodh plugin`_: A notification plugin that pushes events to Aodh, and
  creates/updates alarms appropriately.

* *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.

* *Open vSwitch events Plugin*: A read plugin that retrieves events from OVS.

* *Open vSwitch stats Plugin*: A read plugin that retrieves flow and interface
  stats from OVS.

* *mcelog plugin*: A read plugin that uses mcelog client protocol to check for
  memory Machine Check Exceptions and sends the stats for reported exceptions.

* *PMU plugin*: A read plugin that provides performance counters data on
  Intel CPUs using Linux perf interface.

* *RDT plugin*: A read plugin that provides the last level cache utilization and
  memory bandwidth utilization.

* *virt*: A read plugin that uses virtualization API *libvirt* to gather
  statistics about virtualized guests on a system directly from the hypervisor,
  without a need to install collectd instance on the guest.

* *SNMP Agent*: A write plugin that will act as a AgentX subagent that receives
  and handles queries from SNMP master agent and returns the data collected
  by read plugins. The SNMP Agent plugin handles requests only for OIDs
  specified in configuration file. To handle SNMP queries the plugin gets data
  from collectd and translates requested values from collectd's internal format
  to SNMP format. Supports SNMP: get, getnext and walk requests.

All the plugins above are available on the collectd main branch, except for
the Gnocchi and Aodh plugins as they are Python-based plugins and only C
plugins are accepted by the collectd community. The Gnocchi and Aodh plugins
live in the OpenStack repositories.

.. TODO: Update this to reflect merging of these PRs
Other plugins existing as a pull request into collectd main:

* *Legacy/IPMI*: A read plugin that reports platform thermals, voltages,
  fanspeed, current, flow, power etc. Also, the plugin monitors Intelligent
  Platform Management Interface (IPMI) System Event Log (SEL) and sends the
  appropriate notifications based on monitored SEL events.

* *PCIe AER*: A read plugin that monitors PCIe standard and advanced errors and
  sends notifications about those errors.


Third party application in Barometer repository:

* *Open vSwitch PMD stats*: An aplication that retrieves PMD stats from OVS. It is run
  through exec plugin.

**Plugins and application included in the Euphrates release:**

Write Plugins: aodh plugin, SNMP agent plugin, gnocchi plugin.

Read Plugins/application: Intel RDT plugin, virt plugin, Open vSwitch stats plugin,
Open vSwitch PMD stats application.

Collectd capabilities and usage
-------------------------------
.. Describe the specific capabilities and usage for <XYZ> feature.
.. Provide enough information that a user will be able to operate the feature on a deployed scenario.

The collectd plugins in Anuket are configured with reasonable defaults, but can
be overridden.

Building all Barometer upstreamed plugins from scratch
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The plugins that have been merged to the collectd main branch can all be
built and configured through the barometer repository.

.. note::
 * sudo permissions are required to install collectd.
 * These instructions are for Centos 7.

To build all the upstream plugins, clone the barometer repo:

.. code:: c

    $ git clone https://gerrit.opnfv.org/gerrit/barometer

To install collectd as a service and install all it's dependencies:

.. code:: bash

    $ cd barometer/systems && ./build_base_machine.sh

This will install collectd as a service and the base install directory
will be /opt/collectd.

Sample configuration files can be found in '/opt/collectd/etc/collectd.conf.d'

.. note::
  If you don't want to use one of the Barometer plugins, simply remove the
  sample config file from '/opt/collectd/etc/collectd.conf.d'
.. note::
  If you plan on using the Exec plugin (for OVS_PMD_STATS or for executing scripts
  on notification generation), the plugin requires a non-root user to execute scripts.
  By default, `collectd_exec` user is used in the exec.conf provided in the sample
  configurations directory under src/collectd in the Barometer repo. These scripts *DO NOT* create this user.
  You need to create this user or modify the configuration in the sample configurations directory
  under src/collectd to use another existing non root user before running build_base_machine.sh.

.. note::
  If you are using any Open vSwitch plugins you need to run:

  .. code:: bash

    $ sudo ovs-vsctl set-manager ptcp:6640

After this, you should be able to start collectd as a service

.. code:: bash

    $ sudo systemctl status collectd

If you want to use granfana to display the metrics you collect, please see:
`grafana guide`_

For more information on configuring and installing OpenStack plugins for
collectd, check out the `collectd-openstack-plugins GSG`_.

Below is the per plugin installation and configuration guide, if you only want
to install some/particular plugins.

DPDK telemetry plugin
^^^^^^^^^^^^^^^^^^^^^
Repo: https://github.com/collectd/collectd

Branch: main

Dependencies: `DPDK <https://www.dpdk.org/>`_ (runtime), libjansson (compile-time)

.. note:: DPDK telemetry plugin requires DPDK version 19.08 or later.

To build and install DPDK to /usr please see:
https://github.com/collectd/collectd/blob/main/docs/BUILD.dpdkstat.md

Building and installing collectd:

.. code:: bash

    $ git clone https://github.com/collectd/collectd.git
    $ cd collectd
    $ ./build.sh
    $ ./configure --enable-syslog --enable-logfile --enable-debug
    $ make
    $ sudo make install

This will install collectd to default folder ``/opt/collectd``. The collectd
configuration file (``collectd.conf``) can be found at ``/opt/collectd/etc``.

To configure the dpdk_telemetry plugin you need to modify the configuration file to
include:

.. code:: bash

    LoadPlugin dpdk_telemetry
    <Plugin dpdk_telemetry>
      #ClientSocketPath "/var/run/.client"
      #DpdkSocketPath "/var/run/dpdk/rte/telemetry"
    </Plugin>

The plugin uses default values (as shown) for the socket paths, if you use different values,
uncomment and update ``ClientSocketPath`` and ``DpdkSocketPath`` as required.

For more information on the plugin parameters, please see:
https://github.com/collectd/collectd/blob/main/src/collectd.conf.pod

.. note::

   To gather metrics from a DPDK application, telemetry needs to be enabled.
   This can be done by setting the ``CONFIG_RTE_LIBRTE_TELEMETRY=y`` config flag.
   The application then needs to be run with the ``--telemetry`` EAL option, e.g.
   ::
     $dpdk/app/testpmd --telemetry  -l 2,3,4 -n 4  

For more information on the ``dpdk_telemetry`` plugin, see the `anuket wiki <https://wiki.anuket.io/display/HOME/DPDK+Telemetry+Plugin>`_.

The Address-Space Layout Randomization (ASLR) security feature in Linux should be
disabled, in order for the same hugepage memory mappings to be present in all
DPDK multi-process applications.

To disable ASLR:

.. code:: bash

    $ sudo echo 0 > /proc/sys/kernel/randomize_va_space

To fully enable ASLR:

.. code:: bash

    $ sudo echo 2 > /proc/sys/kernel/randomize_va_space

.. warning:: Disabling Address-Space Layout Randomization (ASLR) may have security
    implications. It is recommended to be disabled only when absolutely necessary,
    and only when all implications of this change have been understood.

For more information on multi-process support, please see:
https://doc.dpdk.org/guides/prog_guide/multi_proc_support.html


Hugepages Plugin
^^^^^^^^^^^^^^^^^
Repo: https://github.com/collectd/collectd

Branch: main

Dependencies: None, but assumes hugepages are configured.

To configure some hugepages:

.. code:: bash

   $ sudo mkdir -p /mnt/huge
   $ sudo mount -t hugetlbfs nodev /mnt/huge
   $ sudo bash -c "echo 14336 > /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages"

Building and installing collectd:

.. code:: bash

    $ git clone https://github.com/collectd/collectd.git
    $ cd collectd
    $ ./build.sh
    $ ./configure --enable-syslog --enable-logfile --enable-hugepages --enable-debug
    $ make
    $ sudo make install

This will install collectd to default folder ``/opt/collectd``. The collectd
configuration file (``collectd.conf``) can be found at ``/opt/collectd/etc``.
To configure the hugepages plugin you need to modify the configuration file to
include:

.. literalinclude:: ../../../src/collectd/collectd_sample_configs/hugepages.conf
   :start-at: LoadPlugin
   :language: bash

For more information on the plugin parameters, please see:
https://github.com/collectd/collectd/blob/main/src/collectd.conf.pod

Intel PMU Plugin
^^^^^^^^^^^^^^^^
Repo: https://github.com/collectd/collectd

Branch: main

Dependencies:

  * PMU tools (jevents library) https://github.com/andikleen/pmu-tools

To be suitable for use in collectd plugin shared library *libjevents* should be
compiled as position-independent code. To do this add the following line to
*pmu-tools/jevents/Makefile*:

.. code:: bash

    CFLAGS += -fPIC

Building and installing *jevents* library:

.. code:: bash

    $ git clone https://github.com/andikleen/pmu-tools.git
    $ cd pmu-tools/jevents/
    $ make
    $ sudo make install

Download the Hardware Events that are relevant to your CPU, download the appropriate
CPU event list json file:

.. code:: bash

    $ wget https://raw.githubusercontent.com/andikleen/pmu-tools/main/event_download.py
    $ python event_download.py

This will download the json files to the location: $HOME/.cache/pmu-events/. If you don't want to
download these files to the aforementioned location, set the environment variable XDG_CACHE_HOME to
the location you want the files downloaded to.

Building and installing collectd:

.. code:: bash

    $ git clone https://github.com/collectd/collectd.git
    $ cd collectd
    $ ./build.sh
    $ ./configure --enable-syslog --enable-logfile --with-libjevents=/usr/local --enable-debug
    $ make
    $ sudo make install

This will install collectd to default folder ``/opt/collectd``. The collectd
configuration file (``collectd.conf``) can be found at ``/opt/collectd/etc``.
To configure the PMU plugin you need to modify the configuration file to
include:

.. literalinclude:: ../../../src/collectd/collectd_sample_configs/intel_pmu.conf
   :start-at: LoadPlugin
   :language: bash

If you want to monitor Intel CPU specific CPU events, make sure to uncomment the
``EventList`` and ``HardwareEvents`` options above.

.. note::
    If you set XDG_CACHE_HOME to anything other than the variable above - you will need to modify
    the path for the EventList configuration.

Use ``Cores`` option to monitor metrics only for configured cores. If an empty string is provided
as value for this field default cores configuration is applied - that is all available cores
are monitored separately. To limit monitoring to cores 0-7 set the option as shown below:

.. code:: bash

    Cores "[0-7]"

For more information on the plugin parameters, please see:
https://github.com/collectd/collectd/blob/main/src/collectd.conf.pod

.. note::

    The plugin opens file descriptors whose quantity depends on number of
    monitored CPUs and number of monitored counters. Depending on configuration,
    it might be required to increase the limit on the number of open file
    descriptors allowed. This can be done using 'ulimit -n' command. If collectd
    is executed as a service 'LimitNOFILE=' directive should be defined in
    [Service] section of *collectd.service* file.

Intel RDT Plugin
^^^^^^^^^^^^^^^^
Repo: https://github.com/collectd/collectd

Branch: main

Dependencies:

* PQoS/Intel RDT library https://github.com/intel/intel-cmt-cat
* msr kernel module

Building and installing PQoS/Intel RDT library:

.. code:: bash

    $ git clone https://github.com/intel/intel-cmt-cat
    $ cd intel-cmt-cat
    $ make
    $ make install PREFIX=/usr

You will need to insert the msr kernel module:

.. code:: bash

    $ modprobe msr

Building and installing collectd:

.. code:: bash

    $ git clone https://github.com/collectd/collectd.git
    $ cd collectd
    $ ./build.sh
    $ ./configure --enable-syslog --enable-logfile --with-libpqos=/usr/ --enable-debug
    $ make
    $ sudo make install

This will install collectd to default folder ``/opt/collectd``. The collectd
configuration file (``collectd.conf``) can be found at ``/opt/collectd/etc``.
To configure the RDT plugin you need to modify the configuration file to
include:

.. literalinclude:: ../../../src/collectd/collectd_sample_configs/rdt.conf
   :start-at: LoadPlugin
   :language: bash

For more information on the plugin parameters, please see:
https://github.com/collectd/collectd/blob/main/src/collectd.conf.pod

IPMI Plugin
^^^^^^^^^^^^
Repo: https://github.com/collectd/collectd

Branch: feat_ipmi_events, feat_ipmi_analog

Dependencies: `OpenIPMI library <https://openipmi.sourceforge.io/>`_

The IPMI plugin is already implemented in the latest collectd and sensors
like temperature, voltage, fanspeed, current are already supported there.
The list of supported IPMI sensors has been extended and sensors like flow,
power are supported now. Also, a System Event Log (SEL) notification feature
has been introduced.

* The feat_ipmi_events branch includes new SEL feature support in collectd
  IPMI plugin. If this feature is enabled, the collectd IPMI plugin will
  dispatch notifications about new events in System Event Log.

* The feat_ipmi_analog branch includes the support of extended IPMI sensors in
  collectd IPMI plugin.

**Install dependencies**

On Centos, install OpenIPMI library:

.. code:: bash

    $ sudo yum install OpenIPMI ipmitool

Anyway, it's recommended to use the latest version of the OpenIPMI library as
it includes fixes of known issues which aren't included in standard OpenIPMI
library package. The latest version of the library can be found at
https://sourceforge.net/p/openipmi/code/ci/master/tree/. Steps to install the
library from sources are described below.

Remove old version of OpenIPMI library:

.. code:: bash

    $ sudo yum remove OpenIPMI ipmitool

Build and install OpenIPMI library:

.. code:: bash

    $ git clone https://git.code.sf.net/p/openipmi/code openipmi-code
    $ cd openipmi-code
    $ autoreconf --install
    $ ./configure --prefix=/usr
    $ make
    $ sudo make install

Add the directory containing ``OpenIPMI*.pc`` files to the ``PKG_CONFIG_PATH``
environment variable:

.. code:: bash

    export PKG_CONFIG_PATH=/usr/lib/pkgconfig

Enable IPMI support in the kernel:

.. code:: bash

    $ sudo modprobe ipmi_devintf
    $ sudo modprobe ipmi_si

.. note::
  If HW supports IPMI, the ``/dev/ipmi0`` character device will be
  created.

Clone and install the collectd IPMI plugin:

.. code:: bash

    $ git clone https://github.com/collectd/collectd
    $ cd collectd
    $ ./build.sh
    $ ./configure --enable-syslog --enable-logfile --enable-debug
    $ make
    $ sudo make install

This will install collectd to default folder ``/opt/collectd``. The collectd
configuration file (``collectd.conf``) can be found at ``/opt/collectd/etc``.
To configure the IPMI plugin you need to modify the file to include:

.. code:: bash

    LoadPlugin ipmi
    <Plugin ipmi>
       <Instance "local">
         SELEnabled true # only feat_ipmi_events branch supports this
       </Instance>
    </Plugin>

.. note::
  By default, IPMI plugin will read all available analog sensor values,
  dispatch the values to collectd and send SEL notifications.

For more information on the IPMI plugin parameters and SEL feature configuration,
please see: https://github.com/collectd/collectd/blob/main/src/collectd.conf.pod

Extended analog sensors support doesn't require additional configuration. The usual
collectd IPMI documentation can be used:

- https://collectd.org/wiki/index.php/Plugin:IPMI
- https://collectd.org/documentation/manpages/collectd.conf.5.shtml#plugin_ipmi

IPMI documentation:

- https://www.kernel.org/doc/Documentation/IPMI.txt
- https://www.intel.com/content/www/us/en/products/docs/servers/ipmi/ipmi-second-gen-interface-spec-v2-rev1-1.html

Mcelog Plugin
^^^^^^^^^^^^^^
Repo: https://github.com/collectd/collectd

Branch: main

Dependencies: `mcelog <http://mcelog.org/>`_

Start by installing mcelog.

.. note::
  The kernel has to have CONFIG_X86_MCE enabled. For 32bit kernels you
  need atleast a 2.6,30 kernel.

On Centos:

.. code:: bash

    $ sudo yum install mcelog

Or build from source

.. code:: bash

    $ git clone https://git.kernel.org/pub/scm/utils/cpu/mce/mcelog.git
    $ cd mcelog
    $ make
    ... become root ...
    $ make install
    $ cp mcelog.service /etc/systemd/system/
    $ systemctl enable mcelog.service
    $ systemctl start mcelog.service


Verify you got a /dev/mcelog. You can verify the daemon is running completely
by running:

.. code:: bash

     $ mcelog --client

This should query the information in the running daemon. If it prints nothing
that is fine (no errors logged yet). More info @
http://www.mcelog.org/installation.html

Modify the mcelog configuration file "/etc/mcelog/mcelog.conf" to include or
enable:

.. code:: bash

    socket-path = /var/run/mcelog-client
    [dimm]
    dimm-tracking-enabled = yes
    dmi-prepopulate = yes
    uc-error-threshold = 1 / 24h
    ce-error-threshold = 10 / 24h

    [socket]
    socket-tracking-enabled = yes
    mem-uc-error-threshold = 100 / 24h
    mem-ce-error-threshold = 100 / 24h
    mem-ce-error-log = yes

    [page]
    memory-ce-threshold = 10 / 24h
    memory-ce-log = yes
    memory-ce-action = soft

    [trigger]
    children-max = 2
    directory = /etc/mcelog


Clone and install the collectd mcelog plugin:

.. code:: bash

    $ git clone https://github.com/collectd/collectd
    $ cd collectd
    $ ./build.sh
    $ ./configure --enable-syslog --enable-logfile --enable-debug
    $ make
    $ sudo make install

This will install collectd to default folder ``/opt/collectd``. The collectd
configuration file (``collectd.conf``) can be found at ``/opt/collectd/etc``.
To configure the mcelog plugin you need to modify the configuration file to
include:

.. literalinclude:: ../../../src/collectd/collectd_sample_configs/mcelog.conf
   :start-at: LoadPlugin
   :language: bash

For more information on the plugin parameters, please see:
https://github.com/collectd/collectd/blob/main/src/collectd.conf.pod

Simulating a Machine Check Exception can be done in one of 3 ways:

* Running $make test in the mcelog cloned directory - mcelog test suite
* using mce-inject
* using mce-test

**mcelog test suite:**

It is always a good idea to test an error handling mechanism before it is
really needed. mcelog includes a test suite. The test suite relies on
mce-inject which needs to be installed and in $PATH.

You also need the mce-inject kernel module configured (with
CONFIG_X86_MCE_INJECT=y), compiled, installed and loaded:

.. code:: bash

    $ modprobe mce-inject

Then you can run the mcelog test suite with

.. code:: bash

    $ make test

This will inject different classes of errors and check that the mcelog triggers
runs. There will be some kernel messages about page offlining attempts. The
test will also lose a few pages of memory in your system (not significant).

.. note::
  This test will kill any running mcelog, which needs to be restarted
  manually afterwards.

**mce-inject:**

A utility to inject corrected, uncorrected and fatal machine check exceptions

.. code:: bash

    $ git clone https://git.kernel.org/pub/scm/utils/cpu/mce/mce-inject.git
    $ cd mce-inject
    $ make
    $ modprobe mce-inject

Modify the test/corrected script to include the following:

.. code:: bash

    CPU 0 BANK 0
    STATUS 0xcc00008000010090
    ADDR 0x0010FFFFFFF

Inject the error:
.. code:: bash

    $ ./mce-inject < test/corrected

.. note::
  The uncorrected and fatal scripts under test will cause a platform reset.
  Only the fatal script generates the memory errors**. In order to  quickly
  emulate uncorrected memory errors and avoid host reboot following test errors
  from mce-test suite can be injected:

.. code:: bash

       $ mce-inject  mce-test/cases/coverage/soft-inj/recoverable_ucr/data/srao_mem_scrub

**mce-test:**

In addition a more in-depth test of the Linux kernel machine check facilities
can be done with the mce-test test suite. mce-test supports testing uncorrected
error handling, real error injection, handling of different soft offlining
cases, and other tests.

**Corrected memory error injection:**

To inject corrected memory errors:

* Remove sb_edac and edac_core kernel modules: rmmod sb_edac rmmod edac_core
* Insert einj module: modprobe einj param_extension=1
* Inject an error by specifying details (last command should be repeated at least two times):

.. code:: bash

    $ APEI_IF=/sys/kernel/debug/apei/einj
    $ echo 0x8 > $APEI_IF/error_type
    $ echo 0x01f5591000 > $APEI_IF/param1
    $ echo 0xfffffffffffff000 > $APEI_IF/param2
    $ echo 1 > $APEI_IF/notrigger
    $ echo 1 > $APEI_IF/error_inject

* Check the MCE statistic: mcelog --client. Check the mcelog log for injected error details: less /var/log/mcelog.

Open vSwitch Plugins
^^^^^^^^^^^^^^^^^^^^
OvS Plugins Repo: https://github.com/collectd/collectd

OvS Plugins Branch: main

OvS Events MIBs: The SNMP OVS interface link status is provided by standard
`IF-MIB <http://www.net-snmp.org/docs/mibs/IF-MIB.txt>`_

Dependencies: Open vSwitch, `Yet Another JSON Library <https://github.com/lloyd/yajl>`_

On Centos, install the dependencies and Open vSwitch:

.. code:: bash

    $ sudo yum install yajl-devel

Steps to install Open vSwtich can be found at
https://docs.openvswitch.org/en/latest/intro/install/fedora/

Start the Open vSwitch service:

.. code:: bash

    $ sudo service openvswitch-switch start

Configure the ovsdb-server manager:

.. code:: bash

    $ sudo ovs-vsctl set-manager ptcp:6640

Clone and install the collectd ovs plugin:

.. code:: bash

    $ git clone $REPO
    $ cd collectd
    $ git checkout main
    $ ./build.sh
    $ ./configure --enable-syslog --enable-logfile --enable-debug
    $ make
    $ sudo make install

This will install collectd to default folder ``/opt/collectd``. The collectd
configuration file (``collectd.conf``) can be found at ``/opt/collectd/etc``.
To configure the OVS events plugin you need to modify the configuration file
(uncommenting and updating values as appropriate) to include:

.. literalinclude:: ../../../src/collectd/collectd_sample_configs/ovs_events.conf
   :start-at: LoadPlugin
   :language: bash

To configure the OVS stats plugin you need to modify the configuration file
(uncommenting and updating values as appropriate) to include:

.. literalinclude:: ../../../src/collectd/collectd_sample_configs/ovs_stats.conf
   :start-at: LoadPlugin
   :language: bash

For more information on the plugin parameters, please see:
https://github.com/collectd/collectd/blob/main/src/collectd.conf.pod

OVS PMD stats
^^^^^^^^^^^^^
Repo: https://gerrit.opnfv.org/gerrit/gitweb?p=barometer.git

Prequistes:

#. Open vSwitch dependencies are installed.
#. Open vSwitch service is running.
#. Ovsdb-server manager is configured.

You can refer `Open vSwitch Plugins`_ section above for each one of them.

OVS PMD stats application is run through the exec plugin.

To configure the OVS PMD stats application you need to modify the exec plugin configuration
to include:

.. code:: bash

    <LoadPlugin exec>
       Interval 1
    </LoadPlugin
    <Plugin exec>
        Exec "user:group" "<path to ovs_pmd_stat.sh>"
    </Plugin>

.. note:: Exec plugin configuration has to be changed to use appropriate user before starting collectd service.

``ovs_pmd_stat.sh`` calls the script for OVS PMD stats application with its argument:

.. literalinclude:: ../../../src/collectd/collectd_sample_configs/ovs_pmd_stats.sh
   :start-at: python
   :language: bash

SNMP Agent Plugin
^^^^^^^^^^^^^^^^^
Repo: https://github.com/collectd/collectd

Branch: main

Dependencies: NET-SNMP library

Start by installing net-snmp and dependencies.

On Centos 7:

.. code:: bash

    $ sudo yum install net-snmp net-snmp-libs net-snmp-utils net-snmp-devel
    $ sudo systemctl start snmpd.service

go to the `snmp configuration`_ steps.

From source:

Clone and build net-snmp:

.. code:: bash

    $ git clone https://github.com/haad/net-snmp.git
    $ cd net-snmp
    $ ./configure --with-persistent-directory="/var/net-snmp" --with-systemd --enable-shared --prefix=/usr
    $ make

Become root

.. code:: bash

    $ make install

Copy default configuration to persistent folder:

.. code:: bash

    $ cp EXAMPLE.conf /usr/share/snmp/snmpd.conf

Set library path and default MIB configuration:

.. code:: bash

    $ cd ~/
    $ echo export LD_LIBRARY_PATH=/usr/lib >> .bashrc
    $ net-snmp-config --default-mibdirs
    $ net-snmp-config --snmpconfpath

Configure snmpd as a service:

.. code:: bash

    $ cd net-snmp
    $ cp ./dist/snmpd.service /etc/systemd/system/
    $ systemctl enable snmpd.service
    $ systemctl start snmpd.service

.. _`snmp configuration`:

Add the following line to snmpd.conf configuration file
``/etc/snmp/snmpd.conf`` to make all OID tree visible for SNMP clients:

.. code:: bash

    view    systemview    included   .1

To verify that SNMP is working you can get IF-MIB table using SNMP client
to view the list of Linux interfaces:

.. code:: bash

    $ snmpwalk -v 2c -c public localhost IF-MIB::interfaces

Get the default MIB location:

.. code:: bash

    $ net-snmp-config --default-mibdirs
    /opt/stack/.snmp/mibs:/usr/share/snmp/mibs

Install Intel specific MIBs (if needed) into location received by
``net-snmp-config`` command (e.g. ``/usr/share/snmp/mibs``).

.. code:: bash

    $ git clone https://gerrit.opnfv.org/gerrit/barometer.git
    $ sudo cp -f barometer/mibs/*.txt /usr/share/snmp/mibs/
    $ sudo systemctl restart snmpd.service

Clone and install the collectd snmp_agent plugin:

.. code:: bash

    $ cd ~
    $ git clone https://github.com/collectd/collectd
    $ cd collectd
    $ ./build.sh
    $ ./configure --enable-syslog --enable-logfile --enable-debug --enable-snmp --with-libnetsnmp
    $ make
    $ sudo make install

This will install collectd to default folder ``/opt/collectd``. The collectd
configuration file (``collectd.conf``) can be found at ``/opt/collectd/etc``.

**SNMP Agent plugin is a generic plugin and cannot work without configuration**.
To configure the snmp_agent plugin you need to modify the configuration file to
include OIDs mapped to collectd types. The following example maps scalar
memAvailReal OID to value represented as free memory type of memory plugin:

.. code:: bash

    LoadPlugin snmp_agent
    <Plugin "snmp_agent">
      <Data "memAvailReal">
        Plugin "memory"
        Type "memory"
        TypeInstance "free"
        OIDs "1.3.6.1.4.1.2021.4.6.0"
      </Data>
    </Plugin>


The ``snmpwalk`` command can be used to validate the collectd configuration:

.. code:: bash

    $ snmpwalk -v 2c -c public localhost 1.3.6.1.4.1.2021.4.6.0
    UCD-SNMP-MIB::memAvailReal.0 = INTEGER: 135237632 kB


**Limitations**

* Object instance with Counter64 type is not supported in SNMPv1. When GetNext
  request is received, Counter64 type objects will be skipped. When Get
  request is received for Counter64 type object, the error will be returned.
* Interfaces that are not visible to Linux like DPDK interfaces cannot be
  retreived using standard IF-MIB tables.

For more information on the plugin parameters, please see:
https://github.com/collectd/collectd/blob/main/src/collectd.conf.pod

For more details on AgentX subagent, please see:
http://www.net-snmp.org/tutorial/tutorial-5/toolkit/demon/

.. _virt-plugin:

virt plugin
^^^^^^^^^^^
Repo: https://github.com/collectd/collectd

Branch: main

Dependencies: `libvirt <https://libvirt.org/>`_, libxml2

On Centos, install the dependencies:

.. code:: bash

    $ sudo yum install libxml2-devel libpciaccess-devel yajl-devel device-mapper-devel

Install libvirt:

.. note:: libvirt version in package manager might be quite old and offer only
    limited functionality. Hence, building and installing libvirt from sources
    is recommended. Detailed instructions can bet found at:
    https://libvirt.org/compiling.html

.. code:: bash

    $ sudo yum install libvirt-devel

Certain metrics provided by the plugin have a requirement on a minimal version of
the libvirt API. *File system information* statistics require a *Guest Agent (GA)*
to be installed and configured in a VM. User must make sure that installed GA
version supports retrieving file system information. Number of *Performance monitoring events*
metrics depends on running libvirt daemon version.

.. note:: Please keep in mind that RDT metrics (part of *Performance monitoring
    events*) have to be supported by hardware. For more details on hardware support,
    please see:
    https://github.com/intel/intel-cmt-cat

    Additionally perf metrics **cannot** be collected if *Intel RDT* plugin is enabled.

libvirt version can be checked with following commands:

.. code:: bash

    $ virsh --version
    $ libvirtd --version

.. table:: Extended statistics requirements

    +-------------------------------+--------------------------+-------------+
    | Statistic                     | Min. libvirt API version | Requires GA |
    +===============================+==========================+=============+
    | Domain reason                 | 0.9.2                    | No          |
    +-------------------------------+--------------------------+-------------+
    | Disk errors                   | 0.9.10                   | No          |
    +-------------------------------+--------------------------+-------------+
    | Job statistics                | 1.2.9                    | No          |
    +-------------------------------+--------------------------+-------------+
    | File system information       | 1.2.11                   | Yes         |
    +-------------------------------+--------------------------+-------------+
    | Performance monitoring events | 1.3.3                    | No          |
    +-------------------------------+--------------------------+-------------+

Start libvirt daemon:

.. code:: bash

    $ systemctl start libvirtd

Create domain (VM) XML configuration file. For more information on domain XML
format and examples, please see:
https://libvirt.org/formatdomain.html

.. note:: Installing additional hypervisor dependencies might be required before
    deploying virtual machine.

Create domain, based on created XML file:

.. code:: bash

    $ virsh define DOMAIN_CFG_FILE.xml

Start domain:

.. code:: bash

    $ virsh start DOMAIN_NAME

Check if domain is running:

.. code:: bash

    $ virsh list

Check list of available *Performance monitoring events* and their settings:

.. code:: bash

    $ virsh perf DOMAIN_NAME

Enable or disable *Performance monitoring events* for domain:

.. code:: bash

    $ virsh perf DOMAIN_NAME [--enable | --disable] EVENT_NAME --live

Clone and install the collectd virt plugin:

.. code:: bash

    $ git clone $REPO
    $ cd collectd
    $ ./build.sh
    $ ./configure --enable-syslog --enable-logfile --enable-debug
    $ make
    $ sudo make install

Where ``$REPO`` is equal to information provided above.

This will install collectd to ``/opt/collectd``. The collectd configuration file
``collectd.conf`` can be found at ``/opt/collectd/etc``.
To load the virt plugin user needs to modify the configuration file to include:

.. code:: bash

    LoadPlugin virt

Additionally, user can specify plugin configuration parameters in this file,
such as connection URL, domain name and much more. By default extended virt plugin
statistics are disabled. They can be enabled with ``ExtraStats`` option.

.. code:: bash

    <Plugin virt>
       RefreshInterval 60
       ExtraStats "cpu_util disk disk_err domain_state fs_info job_stats_background pcpu perf vcpupin"
    </Plugin>

For more information on the plugin parameters, please see:
https://github.com/collectd/collectd/blob/main/src/collectd.conf.pod

.. _install-collectd-as-a-service:

Installing collectd as a service
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Collectd service scripts are available in the collectd/contrib directory.
To install collectd as a service:

.. code:: bash

    $ sudo cp contrib/systemd.collectd.service /etc/systemd/system/
    $ cd /etc/systemd/system/
    $ sudo mv systemd.collectd.service collectd.service
    $ sudo chmod +x collectd.service

Modify collectd.service

.. code:: bash

    [Service]
    ExecStart=/opt/collectd/sbin/collectd
    EnvironmentFile=-/opt/collectd/etc/
    EnvironmentFile=-/opt/collectd/etc/
    CapabilityBoundingSet=CAP_SETUID CAP_SETGID

Reload

.. code:: bash

    $ sudo systemctl daemon-reload
    $ sudo systemctl start collectd.service
    $ sudo systemctl status collectd.service should show success

Additional useful plugins
^^^^^^^^^^^^^^^^^^^^^^^^^

**Exec Plugin** : Can be used to show you when notifications are being
generated by calling a bash script that dumps notifications to file. (handy
for debug). Modify ``/opt/collectd/etc/collectd.conf`` to include the
``NotificationExec`` config option, taking care to add the right directory path
to the ``write_notification.sh`` script:

.. literalinclude:: ../../../src/collectd/collectd_sample_configs/exec.conf
   :start-at: LoadPlugin
   :emphasize-lines: 6
   :language: bash

``write_notification.sh`` writes the notification passed from exec through
STDIN to a file (``/tmp/notifications``):

.. literalinclude:: ../../../src/collectd/collectd_sample_configs/write_notification.sh
   :start-at: rm -f
   :language: bash

output to ``/tmp/notifications`` should look like:

.. code:: bash

    Severity:WARNING
    Time:1479991318.806
    Host:localhost
    Plugin:ovs_events
    PluginInstance:br-ex
    Type:gauge
    TypeInstance:link_status
    uuid:f2aafeec-fa98-4e76-aec5-18ae9fc74589

    linkstate of "br-ex" interface has been changed to "DOWN"

* **logfile plugin**: Can be used to log collectd activity. Modify
  /opt/collectd/etc/collectd.conf to include:

.. code:: bash

    LoadPlugin logfile
    <Plugin logfile>
        LogLevel info
        File "/var/log/collectd.log"
        Timestamp true
        PrintSeverity false
    </Plugin>


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 OpenStack through the
collectd-openstack-plugins.

To see this demo in action please checkout: `Barometer OPNFV Summit demo`_

For more information on configuring and installing OpenStack plugins for
collectd, check out the `collectd-openstack-plugins GSG`_.

Security
^^^^^^^^
* AAA – on top of collectd there secure agents like SNMP V3, Openstack agents
  etc. with their own AAA methods.

* Collectd runs as a daemon with root permissions.

* The `Exec plugin`_ allows the execution of external programs but counters the security
  concerns by:

  * Ensuring that only one instance of the program is executed by collectd at any time
  * Forcing the plugin to check that custom programs are never executed with superuser
    privileges.

* Protection of Data in flight:

  * It's recommend to use a minimum version of 4.7 of the Network plugin which provides
    the possibility to cryptographically sign or encrypt the network traffic.
  * Write Redis plugin or the Write MongoDB plugin are recommended to store the data.
  * For more information, please see: https://collectd.org/wiki/index.php?title=Networking_introduction

* Known vulnerabilities include:

  * https://www.cvedetails.com/vulnerability-list/vendor_id-11242/Collectd.html

    * `CVE-2017-7401`_ fixed https://github.com/collectd/collectd/issues/2174 in Version 5.7.2.
    * `CVE-2016-6254`_ fixed https://mailman.verplant.org/pipermail/collectd/2016-July/006838.html
        in Version  5.4.3.
    * `CVE-2010-4336`_ fixed https://mailman.verplant.org/pipermail/collectd/2010-November/004277.html
        in Version 4.10.2.

  * https://www.cvedetails.com/product/20310/Collectd-Collectd.html?vendor_id=11242

* It's recommended to only use collectd plugins from signed packages.

References
^^^^^^^^^^^
.. [1] https://collectd.org/wiki/index.php/Naming_schema
.. [2] https://github.com/collectd/collectd/blob/main/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

.. _Barometer OPNFV Summit demo: https://prezi.com/kjv6o8ixs6se/software-fastpath-service-quality-metrics-demo/
.. _gnocchi plugin: https://opendev.org/x/collectd-openstack-plugins/src/branch/stable/ocata/
.. _aodh plugin: https://opendev.org/x/collectd-openstack-plugins/src/branch/stable/ocata/
.. _collectd-openstack-plugins GSG: https://opendev.org/x/collectd-openstack-plugins/src/branch/master/doc/source/GSG.rst
.. _grafana guide: https://wiki.anuket.io/display/HOME/Installing+and+configuring+InfluxDB+and+Grafana+to+display+metrics+with+collectd 
.. _CVE-2017-7401: https://www.cvedetails.com/cve/CVE-2017-7401/
.. _CVE-2016-6254: https://www.cvedetails.com/cve/CVE-2016-6254/
.. _CVE-2010-4336: https://www.cvedetails.com/cve/CVE-2010-4336/
.. _Exec plugin: https://collectd.org/wiki/index.php/Plugin:Exec