Todo
Update a lot of the links in here.
Use OpenStack Compute to host and manage cloud computing systems. OpenStack Compute is a major part of an Infrastructure-as-a-Service (IaaS) system. The main modules are implemented in Python.
OpenStack Compute interacts with OpenStack Identity for authentication; OpenStack Image service for disk and server images; and OpenStack Dashboard for the user and administrative interface. Image access is limited by projects, and by users; quotas are limited per project (the number of instances, for example). OpenStack Compute can scale horizontally on standard hardware, and download images to launch instances.
OpenStack Compute consists of the following areas and their components:
nova-api
servicenova-api-metadata
servicenova-api-metadata
service
is generally used when you run in multi-host mode with nova-network
installations. For details, see Metadata service
in the Compute Administrator Guide.nova-compute
serviceA worker daemon that creates and terminates virtual machine instances through hypervisor APIs. For example:
Processing is fairly complex. Basically, the daemon accepts actions from the queue and performs a series of system commands such as launching a KVM instance and updating its state in the database.
nova-placement-api
servicenova-scheduler
servicenova-conductor
modulenova-compute
service and the database.
It eliminates direct accesses to the cloud database made by the
nova-compute
service. The nova-conductor
module scales horizontally.
However, do not deploy it on nodes where the nova-compute
service runs.
For more information, see the conductor
section in the
Configuration Options.nova-consoleauth
daemonAuthorizes tokens for users that console proxies provide. See
nova-novncproxy
and nova-xvpvncproxy
. This service must be running
for console proxies to work. You can run proxies of either type against a
single nova-consoleauth service in a cluster configuration. For information,
see About nova-consoleauth.
Deprecated since version 18.0.0: nova-consoleauth
is deprecated since 18.0.0 (Rocky) and will be removed
in an upcoming release. See
workarounds.enable_consoleauth
for details.
nova-novncproxy
daemonnova-spicehtml5proxy
daemonnova-xvpvncproxy
daemonStores most build-time and run-time states for a cloud infrastructure, including:
Theoretically, OpenStack Compute can support any database that SQLAlchemy supports. Common databases are SQLite3 for test and development work, MySQL, MariaDB, and PostgreSQL.
Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.