a2d662d600
The XML root element of Docbook XML files should match the following format: <ELEMENT 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="THE_XML_ID_OF_THE_ELEMENT"> Change-Id: I1e0804e2c5021bd78b77483f3156c5b069453555
157 lines
7.7 KiB
XML
157 lines
7.7 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
|
|
<chapter 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="ch_overview">
|
|
<?dbhtml stop-chunking?>
|
|
<title>Architecture</title>
|
|
<section xml:id="architecture_overview">
|
|
<title>Overview</title>
|
|
<para>The <glossterm>OpenStack</glossterm> project is an open source cloud
|
|
computing platform that supports all types of cloud environments. The
|
|
project aims for simple implementation, massive scalability, and a rich
|
|
set of features. Cloud computing experts from around the world
|
|
contribute to the project.</para>
|
|
<para>OpenStack provides an Infrastructure-as-a-Service
|
|
(<glossterm>IaaS</glossterm>) solution through a variety of complemental
|
|
services. Each service offers an application programming interface
|
|
(<glossterm>API</glossterm>) that facilitates this integration. The
|
|
following table provides a list of OpenStack services:</para>
|
|
<xi:include href="../common/ch_getstart.xml"
|
|
xpointer="element(table1)"/>
|
|
<para>This guide describes how to deploy these services in a functional
|
|
test environment and, by example, teaches you how to build a production
|
|
environment.</para>
|
|
</section>
|
|
<section xml:id="architecture_conceptual-architecture">
|
|
<title>Conceptual architecture</title>
|
|
<para>Launching a virtual machine or instance involves many interactions
|
|
among several services. The following diagram provides the conceptual
|
|
architecture of a typical OpenStack environment.</para>
|
|
<figure xml:id="conceptual-architecture">
|
|
<title>Conceptual architecture</title>
|
|
<mediaobject>
|
|
<imageobject>
|
|
<imagedata contentwidth="6in"
|
|
fileref="../common/figures/openstack_havana_conceptual_arch.png"/>
|
|
</imageobject>
|
|
</mediaobject>
|
|
</figure>
|
|
</section>
|
|
<section xml:id="architecture_example-architectures">
|
|
<title>Example architectures</title>
|
|
<para>OpenStack is highly configurable to meet different needs with various
|
|
compute, networking, and storage options. This guide enables you to
|
|
choose your own OpenStack adventure using a combination of basic and
|
|
optional services. This guide uses the following example
|
|
architectures:</para>
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>Three-node architecture with OpenStack Networking (neutron). See <xref linkend="example-architecture-with-neutron-networking"/>.</para>
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>The basic controller node runs the Identity service, Image
|
|
Service, management portions of Compute and Networking,
|
|
Networking plug-in, and the dashboard. It also includes
|
|
supporting services such as a database,
|
|
<glossterm>message broker</glossterm>, and
|
|
<glossterm>Network Time Protocol (NTP)</glossterm>.
|
|
</para>
|
|
<para>Optionally, the controller node also runs portions of
|
|
Block Storage, Object Storage, Database Service, Orchestration,
|
|
and Telemetry. These components provide additional features for
|
|
your environment.</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>The network node runs the Networking plug-in, layer 2 agent,
|
|
and several layer 3 agents that provision and operate tenant
|
|
networks. Layer 2 services include provisioning of virtual
|
|
networks and tunnels. Layer 3 services include routing,
|
|
<glossterm baseform="Network Address Translation (NAT)">NAT</glossterm>
|
|
, and <glossterm>DHCP</glossterm>. This node also handles
|
|
external (internet) connectivity for tenant virtual machines
|
|
or instances.</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>The compute node runs the hypervisor portion of Compute,
|
|
which operates tenant virtual machines or instances. By default
|
|
Compute uses KVM as the hypervisor. The compute node also runs
|
|
the Networking plug-in and layer 2 agent which operate tenant
|
|
networks and implement security groups. You can run more than
|
|
one compute node.</para>
|
|
<para>Optionally, the compute node also runs the Telemetry
|
|
agent. This component provides additional features for
|
|
your environment.</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
<note>
|
|
<para>When you implement this architecture, skip
|
|
<xref linkend="section_nova-networking" /> in
|
|
<xref linkend="ch_networking" />. To use optional services, you
|
|
might need to install additional nodes, as described in
|
|
subsequent chapters.</para>
|
|
</note>
|
|
<figure xml:id="example-architecture-with-neutron-networking">
|
|
<title>Three-node architecture with OpenStack Networking (neutron)</title>
|
|
<mediaobject>
|
|
<imageobject>
|
|
<imagedata contentwidth="6in"
|
|
fileref="figures/installguide_arch-neutron.png"/>
|
|
</imageobject>
|
|
</mediaobject>
|
|
</figure>
|
|
</listitem>
|
|
<listitem>
|
|
<para>Two-node architecture with legacy networking (nova-network). See
|
|
<xref linkend="example-architecture-with-legacy-networking"/>.</para>
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>The basic
|
|
<glossterm baseform="cloud controller node">controller node</glossterm>
|
|
runs the Identity service, Image Service, management portion of
|
|
Compute, and the dashboard necessary to launch a simple instance.
|
|
It also includes supporting services such as a database, message
|
|
broker, and NTP.</para>
|
|
<para>Optionally, the controller node also runs portions of
|
|
Block Storage, Object Storage, Database Service, Orchestration,
|
|
and Telemetry. These components provide additional features for
|
|
your environment.</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>The basic <glossterm>compute node</glossterm> runs the
|
|
<glossterm>hypervisor</glossterm> portion of Compute,
|
|
which operates <glossterm>tenant</glossterm>
|
|
<glossterm baseform="virtual machine (VM)">virtual machines</glossterm>
|
|
or instances. By default, Compute uses
|
|
<glossterm baseform="kernel-based VM (KVM)">KVM</glossterm>
|
|
as the <glossterm>hypervisor</glossterm>. Compute also
|
|
provisions and operates tenant networks and implements
|
|
<glossterm baseform="security group">security groups</glossterm>.
|
|
You can run more than one compute node.</para>
|
|
<para>Optionally, the compute node also runs the Telemetry
|
|
agent. This component provides additional features for
|
|
your environment.</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
<note>
|
|
<para>When you implement this architecture, skip
|
|
<xref linkend="section_neutron-networking" /> in
|
|
<xref linkend="ch_networking" />. To use optional services, you
|
|
might need to install additional nodes, as described in
|
|
subsequent chapters.</para>
|
|
</note>
|
|
<figure xml:id="example-architecture-with-legacy-networking">
|
|
<title>Two-node architecture with legacy networking (nova-network)</title>
|
|
<mediaobject>
|
|
<imageobject>
|
|
<imagedata contentwidth="6in"
|
|
fileref="figures/installguide_arch-nova.png"/>
|
|
</imageobject>
|
|
</mediaobject>
|
|
</figure>
|
|
</listitem>
|
|
</itemizedlist>
|
|
</section>
|
|
</chapter>
|