a7584ec1a5
Alembic does lots of new things. Provide docs for how to use this. We also improve upgrade docs slightly, removing references to ancient reviews that are no longer really helpful as well as calling out our N -> N+1 constraint. Change-Id: I3760b82ce3bd71aa0a760d7137d69dfa3f29dc1d Signed-off-by: Stephen Finucane <stephenfin@redhat.com>
158 lines
4.7 KiB
ReStructuredText
158 lines
4.7 KiB
ReStructuredText
=======
|
|
Compute
|
|
=======
|
|
|
|
The OpenStack Compute service allows you to control an
|
|
Infrastructure-as-a-Service (IaaS) cloud computing platform. It gives you
|
|
control over instances and networks, and allows you to manage access to the
|
|
cloud through users and projects.
|
|
|
|
Compute does not include virtualization software. Instead, it defines drivers
|
|
that interact with underlying virtualization mechanisms that run on your host
|
|
operating system, and exposes functionality over a web-based API.
|
|
|
|
|
|
Overview
|
|
--------
|
|
|
|
To effectively administer compute, you must understand how the different
|
|
installed nodes interact with each other. Compute can be installed in many
|
|
different ways using multiple servers, but generally multiple compute nodes
|
|
control the virtual servers and a cloud controller node contains the remaining
|
|
Compute services.
|
|
|
|
The Compute cloud works using a series of daemon processes named ``nova-*``
|
|
that exist persistently on the host machine. These binaries can all run on the
|
|
same machine or be spread out on multiple boxes in a large deployment. The
|
|
responsibilities of services and drivers are:
|
|
|
|
.. rubric:: Services
|
|
|
|
``nova-api``
|
|
Receives XML requests and sends them to the rest of the system. A WSGI app
|
|
routes and authenticates requests. Supports the OpenStack Compute APIs. A
|
|
``nova.conf`` configuration file is created when Compute is installed.
|
|
|
|
.. todo::
|
|
|
|
Describe nova-api-metadata, nova-api-os-compute, nova-serialproxy and
|
|
nova-spicehtml5proxy
|
|
|
|
nova-console, nova-dhcpbridge and nova-xvpvncproxy are all deprecated for
|
|
removal so they can be ignored.
|
|
|
|
``nova-compute``
|
|
Manages virtual machines. Loads a Service object, and exposes the public
|
|
methods on ComputeManager through a Remote Procedure Call (RPC).
|
|
|
|
``nova-conductor``
|
|
Provides database-access support for compute nodes (thereby reducing security
|
|
risks).
|
|
|
|
``nova-scheduler``
|
|
Dispatches requests for new virtual machines to the correct node.
|
|
|
|
``nova-novncproxy``
|
|
Provides a VNC proxy for browsers, allowing VNC consoles to access virtual
|
|
machines.
|
|
|
|
.. note::
|
|
|
|
Some services have drivers that change how the service implements its core
|
|
functionality. For example, the ``nova-compute`` service supports drivers
|
|
that let you choose which hypervisor type it can use.
|
|
|
|
.. toctree::
|
|
:maxdepth: 2
|
|
|
|
manage-volumes
|
|
flavors
|
|
default-ports
|
|
admin-password-injection
|
|
manage-the-cloud
|
|
manage-logs
|
|
root-wrap-reference
|
|
configuring-migrations
|
|
live-migration-usage
|
|
remote-console-access
|
|
service-groups
|
|
node-down
|
|
upgrades
|
|
|
|
|
|
Advanced configuration
|
|
----------------------
|
|
|
|
OpenStack clouds run on platforms that differ greatly in the capabilities that
|
|
they provide. By default, the Compute service seeks to abstract the underlying
|
|
hardware that it runs on, rather than exposing specifics about the underlying
|
|
host platforms. This abstraction manifests itself in many ways. For example,
|
|
rather than exposing the types and topologies of CPUs running on hosts, the
|
|
service exposes a number of generic CPUs (virtual CPUs, or vCPUs) and allows
|
|
for overcommitting of these. In a similar manner, rather than exposing the
|
|
individual types of network devices available on hosts, generic
|
|
software-powered network ports are provided. These features are designed to
|
|
allow high resource utilization and allows the service to provide a generic
|
|
cost-effective and highly scalable cloud upon which to build applications.
|
|
|
|
This abstraction is beneficial for most workloads. However, there are some
|
|
workloads where determinism and per-instance performance are important, if not
|
|
vital. In these cases, instances can be expected to deliver near-native
|
|
performance. The Compute service provides features to improve individual
|
|
instance for these kind of workloads.
|
|
|
|
.. include:: /common/numa-live-migration-warning.txt
|
|
|
|
.. toctree::
|
|
:maxdepth: 2
|
|
|
|
pci-passthrough
|
|
cpu-topologies
|
|
real-time
|
|
huge-pages
|
|
virtual-gpu
|
|
file-backed-memory
|
|
ports-with-resource-requests
|
|
virtual-persistent-memory
|
|
emulated-tpm
|
|
uefi
|
|
secure-boot
|
|
sev
|
|
managing-resource-providers
|
|
resource-limits
|
|
cpu-models
|
|
libvirt-misc
|
|
|
|
|
|
Additional guides
|
|
-----------------
|
|
|
|
.. TODO(mriedem): This index page has a lot of content which should be
|
|
organized into groups for things like configuration, operations,
|
|
troubleshooting, etc.
|
|
|
|
.. toctree::
|
|
:maxdepth: 2
|
|
|
|
aggregates
|
|
arch
|
|
availability-zones
|
|
cells
|
|
config-drive
|
|
configuration/index
|
|
evacuate
|
|
image-caching
|
|
metadata-service
|
|
migration
|
|
migrate-instance-with-snapshot
|
|
networking
|
|
quotas
|
|
security-groups
|
|
security
|
|
services
|
|
ssh-configuration
|
|
support-compute
|
|
secure-live-migration-with-qemu-native-tls
|
|
vendordata
|
|
hw-machine-type
|