openstack-manuals/doc/admin-guide-cloud/telemetry/section_telemetry-system-architecture.xml
Ildiko Vancsa 95a077a0ff Add content and ToC to Telemetry Admin guide
Add content to the section System architecture and Data collection
and add table of contents to Retrieving data and Alarming.

Implements: blueprint add-ceilometer-admin-guide-to-openstack-manuals
Change-Id: I56065c21d62e3477900981a4f37af0cc95fe64b9
2014-08-23 21:43:54 +02:00

220 lines
9.1 KiB
XML

<?xml version="1.0" encoding="UTF-8"?>
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:xlink="http://www.w3.org/1999/xlink"
version="5.0"
xml:id="section_telemetry-system-architecture">
<title>System architecture</title>
<para>The Telemetry module uses an agent-based architecture.
Several modules combine their responsibilities to collect data,
store samples in a database, or provide an API service for handling
incoming requests.</para>
<para>The Telemetry module is built from the following agents and
services:</para>
<para>
<variablelist>
<varlistentry>
<term><systemitem class="service">ceilometer-api</systemitem></term>
<listitem>
<para>Presents aggregated metering data to consumers
(such as billing engines, analytics tools and so forth).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><systemitem class="service">ceilometer-agent-central</systemitem></term>
<listitem>
<para>Polls the public RESTful APIs of other OpenStack
services such as Compute service and Image service, in order to
keep tabs on resource existence.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><systemitem class="service">ceilometer-agent-compute</systemitem></term>
<listitem>
<para>Polls the local hypervisor or libvirt daemon to acquire
performance data for the local instances, messages and emits these
data as AMQP messages.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><systemitem class="service">ceilometer-agent-notification</systemitem></term>
<listitem>
<para>Consumes AMQP messages from other OpenStack services.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><systemitem class="service">ceilometer-collector</systemitem></term>
<listitem>
<para>Consumes AMQP notifications from the agents, then dispatches
these data to the metering store.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><systemitem class="service">ceilometer-alarm-evaluator</systemitem></term>
<listitem>
<para>Determines when alarms fire due to the associated statistic
trend crossing a threshold over a sliding time window.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><systemitem class="service">ceilometer-alarm-notifier</systemitem></term>
<listitem>
<para>Initiates alarm actions, for example calling out to a webhook
with a description of the alarm state transition.</para>
</listitem>
</varlistentry>
</variablelist>
</para>
<para>Besides the <systemitem class="service">ceilometer-agent-compute</systemitem> service,
all the other services are placed on one or more controller nodes.</para>
<note>
<para>The <systemitem class="service">ceilometer-agent-central</systemitem> service does
not support multiple running instances at a time, it can have only one.</para>
</note>
<para>The Telemetry architecture highly depends on the AMQP service both for consuming
notifications coming from OpenStack services and internal communication.</para>
<section xml:id="section_telemetry-supported-dbs">
<title>Supported databases</title>
<para>The other key external component of Telemetry is the database, where the samples, alarm
definitions and alarms are stored.</para>
<note>
<para>Multiple database backends can be configured in order to store samples and alarms
separately.</para>
</note>
<para>The list of supported database backends:</para>
<para>
<itemizedlist>
<listitem>
<para><link xlink:href="http://www.mongodb.org/">MongoDB</link></para>
</listitem>
<listitem>
<para><link xlink:href="http://www.mysql.com/">MySQL</link></para>
</listitem>
<listitem>
<para><link xlink:href="http://www.postgresql.org/">PostgreSQL</link></para>
</listitem>
<listitem>
<para><link xlink:href="http://hbase.apache.org/">HBase</link></para>
</listitem>
<listitem>
<para><link xlink:href="http://www-01.ibm.com/software/data/db2/">DB2</link>
</para>
</listitem>
</itemizedlist>
</para>
</section>
<section xml:id="section_telemetry-supported-hypervisors">
<title>Supported hypervisors</title>
<para>The Telemetry module collects information about the virtual machines, which requires
close connection to the hypervisor that runs on the compute hosts.</para>
<para>The list of supported hypervisors is:</para>
<para>
<itemizedlist>
<listitem>
<para>The following hypervisors are supported via
<link xlink:href="http://libvirt.org/">Libvirt</link>:</para>
<itemizedlist>
<listitem>
<para>
<link xlink:href="http://www.linux-kvm.org/page/Main_Page">Kernel-based
Virtual Machine (KVM)</link>
</para>
</listitem>
<listitem>
<para>
<link xlink:href="http://wiki.qemu.org/Main_Page">Quick Emulator (QEMU)</link>
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://linuxcontainers.org/">Linux Containers (LXC)</link>
</para>
</listitem>
<listitem>
<para>
<link xlink:href="http://www.xenproject.org/help/documentation.html">XEN</link>
</para>
</listitem>
<listitem>
<para>
<link xlink:href="http://user-mode-linux.sourceforge.net/">
User-mode Linux (UML)</link>
</para>
</listitem>
</itemizedlist>
<note>
<para>For details about hypervisor support in Libvirt please check the
<link xlink:href="http://libvirt.org/hvsupport.html">Libvirt API
support matrix</link>.
</para>
</note>
</listitem>
<listitem>
<para><link
xlink:href="http://www.microsoft.com/en-us/server-cloud/hyper-v-server/default.aspx"
>Hyper-V</link>
</para>
</listitem>
<listitem>
<para><link
xlink:href="http://www.vmware.com/products/vsphere-hypervisor/support.html"
>VMWare vSphere</link>
</para>
</listitem>
</itemizedlist>
</para>
</section>
<section xml:id="section_telemetry-supported-networking-services">
<title>Suported networking services</title>
<para>Telemetry is able to retrieve information from OpenStack Networking
and external networking services:</para>
<para>
<itemizedlist>
<listitem>
<para>OpenStack Networking:
<itemizedlist>
<listitem>
<para>Basic network metrics</para>
</listitem>
<listitem>
<para>Firewall-as-a-Service (FWaaS) metrics</para>
</listitem>
<listitem>
<para>Loadbalancer-as-a-Service (LBaaS) metrics</para>
</listitem>
<listitem>
<para>VPN-as-a-Service (VPNaaS) metrics</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>SDN controller metrics:
<itemizedlist>
<listitem>
<para><link xlink:href="http://www.opendaylight.org/software">
OpenDaylight</link></para>
</listitem>
<listitem>
<para><link xlink:href="http://opencontrail.org/">OpenContrail</link></para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</para>
</section>
<section xml:id="section_telemetry-users-roles">
<title>Users, roles and tenants</title>
<para>This module of OpenStack uses OpenStack Identity for authenticating and authorizing
users. The required configuration options are listed in the <link xlink:href=
"http://docs.openstack.org/trunk/config-reference/content/ch_configuring-openstack-telemetry.html">
Telemetry section</link> in the <citetitle>OpenStack Configuration Reference</citetitle>.</para>
<para>Two roles are used in the system basically, which are the 'admin' and 'non-admin'. The
authorization happens before processing each API request. The amount of returned data depends
on the role the requestor owns.</para>
<para>The creation of alarm definitions also highly depends on the role of the user, who
initiated the action. Further details about alarm handling can be found in
<xref linkend="section_telemetry-alarms"/> in this guide.</para>
</section>
</section>