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========
Glossary
========
.. comments
This file is automatically generated, edit the master doc/glossary/glossary-terms.xml to update it.
This glossary offers a list of terms and definitions to define a
vocabulary for OpenStack-related concepts.
To add to OpenStack glossary, clone the `openstack/openstack-manuals repository <https://git.openstack.org/cgit/openstack/openstack-manuals>`__ and update the source file
``doc/glossary/glossary-terms.xml`` through the
OpenStack contribution process.
.. glossary::
6to4
A mechanism that allows IPv6 packets to be transmitted
over an IPv4 network, providing a strategy for migrating to
IPv6.
absolute limit
Impassable limits for guest VMs. Settings include total RAM
size, maximum number of vCPUs, and maximum disk size.
access control list
A list of permissions attached to an object. An ACL specifies
which users or system processes have access to objects. It also
defines which operations can be performed on specified objects. Each
entry in a typical ACL specifies a subject and an operation. For
instance, the ACL entry ``(Alice, delete)`` for a file gives
Alice permission to delete the file.
access key
Alternative term for an Amazon EC2 access key. See EC2 access
key.
account
The Object Storage context of an account. Do not confuse with a
user account from an authentication service, such as Active Directory,
/etc/passwd, OpenLDAP, OpenStack Identity, and so on.
account auditor
Checks for missing replicas and incorrect or corrupted objects
in a specified Object Storage account by running queries against the
back-end SQLite database.
account database
A SQLite database that contains Object Storage accounts and
related metadata and that the accounts server accesses.
account reaper
An Object Storage worker that scans for and deletes account
databases and that the account server has marked for deletion.
account server
Lists containers in Object Storage and stores container
information in the account database.
account service
An Object Storage component that provides account services such
as list, create, modify, and audit. Do not confuse with OpenStack
Identity service, OpenLDAP, or similar user-account services.
accounting
The Compute service provides accounting information through the
event notification and system usage data facilities.
ACL
See access control list.
active/active configuration
In a high-availability setup with an active/active
configuration, several systems share the load together and if one
fails, the load is distributed to the remaining systems.
Active Directory
Authentication and identity service by Microsoft, based on LDAP.
Supported in OpenStack.
active/passive configuration
In a high-availability setup with an active/passive
configuration, systems are set up to bring additional resources online
to replace those that have failed.
address pool
A group of fixed and/or floating IP addresses that are assigned
to a project and can be used by or assigned to the VM instances in a
project.
admin API
A subset of API calls that are accessible to authorized
administrators and are generally not accessible to end users or the
public Internet. They can exist as a separate service (keystone) or
can be a subset of another API (nova).
administrator
The person responsible for installing, configuring,
and managing an OpenStack cloud.
admin server
In the context of the Identity service, the worker process that
provides access to the admin API.
Advanced Message Queuing Protocol (AMQP)
The open standard messaging protocol used by OpenStack
components for intra-service communications, provided by RabbitMQ,
Qpid, or ZeroMQ.
Advanced RISC Machine (ARM)
Lower power consumption CPU often found in mobile and embedded
devices. Supported by OpenStack.
alert
The Compute service can send alerts through its notification
system, which includes a facility to create custom notification
drivers. Alerts can be sent to and displayed on the horizon
dashboard.
allocate
The process of taking a floating IP address from the address
pool so it can be associated with a fixed IP on a guest VM
instance.
Amazon Kernel Image (AKI)
Both a VM container format and disk format. Supported by Image
service.
Amazon Machine Image (AMI)
Both a VM container format and disk format. Supported by Image
service.
Amazon Ramdisk Image (ARI)
Both a VM container format and disk format. Supported by Image
service.
Anvil
A project that ports the shell script-based project named
DevStack to Python.
Apache
The Apache Software Foundation supports the Apache community of
open-source software projects. These projects provide software
products for the public good.
Apache License 2.0
All OpenStack core projects are provided under the terms of the
Apache License 2.0 license.
Apache Web Server
The most common web server software currently used on the
Internet.
API endpoint
The daemon, worker, or service that a client communicates with
to access an API. API endpoints can provide any number of services,
such as authentication, sales data, performance meters, Compute VM
commands, census data, and so on.
API extension
Custom modules that extend some OpenStack core APIs.
API extension plug-in
Alternative term for a Networking plug-in or Networking API
extension.
API key
Alternative term for an API token.
API server
Any node running a daemon or worker that provides an API
endpoint.
API token
Passed to API requests and used by OpenStack to verify that the
client is authorized to run the requested operation.
API version
In OpenStack, the API version for a project is part of the URL.
For example, ``example.com/nova/v1/foobar``.
applet
A Java program that can be embedded into a web page.
Application Programming Interface (API)
A collection of specifications used to access a service,
application, or program. Includes service calls, required parameters
for each call, and the expected return values.
Application Catalog service
OpenStack project that provides an application catalog
service so that users can compose and deploy composite
environments on an application abstraction level while
managing the application lifecycle. The code name of the
project is murano.
application server
A piece of software that makes available another piece of
software over a network.
Application Service Provider (ASP)
Companies that rent specialized applications that help
businesses and organizations provide additional services
with lower cost.
Address Resolution Protocol (ARP)
The protocol by which layer-3 IP addresses are resolved into
layer-2 link local addresses.
arptables
Tool used for maintaining Address Resolution Protocol packet
filter rules in the Linux kernel firewall modules. Used along with
iptables, ebtables, and ip6tables in Compute to provide firewall
services for VMs.
associate
The process associating a Compute floating IP address with a
fixed IP address.
Asynchronous JavaScript and XML (AJAX)
A group of interrelated web development techniques used on the
client-side to create asynchronous web applications. Used extensively
in horizon.
ATA over Ethernet (AoE)
A disk storage protocol tunneled within Ethernet.
attach
The process of connecting a VIF or vNIC to a L2 network in
Networking. In the context of Compute, this process connects a storage
volume to an instance.
attachment (network)
Association of an interface ID to a logical port. Plugs an
interface into a port.
auditing
Provided in Compute through the system usage data
facility.
auditor
A worker process that verifies the integrity of Object Storage
objects, containers, and accounts. Auditors is the collective term for
the Object Storage account auditor, container auditor, and object
auditor.
Austin
The code name for the initial release of
OpenStack. The first design summit took place in
Austin, Texas, US.
auth node
Alternative term for an Object Storage authorization
node.
authentication
The process that confirms that the user, process, or client is
really who they say they are through private key, secret token,
password, fingerprint, or similar method.
authentication token
A string of text provided to the client after authentication.
Must be provided by the user or process in subsequent requests to the
API endpoint.
AuthN
The Identity service component that provides authentication
services.
authorization
The act of verifying that a user, process, or client is
authorized to perform an action.
authorization node
An Object Storage node that provides authorization
services.
AuthZ
The Identity component that provides high-level
authorization services.
Auto ACK
Configuration setting within RabbitMQ that enables or disables
message acknowledgment. Enabled by default.
auto declare
A Compute RabbitMQ setting that determines whether a message
exchange is automatically created when the program starts.
availability zone
An Amazon EC2 concept of an isolated area that is used for fault
tolerance. Do not confuse with an OpenStack Compute zone or
cell.
AWS
Amazon Web Services.
AWS CloudFormation template
AWS CloudFormation allows AWS users to create and manage a
collection of related resources. The Orchestration service
supports a CloudFormation-compatible format (CFN).
back end
Interactions and processes that are obfuscated from the user,
such as Compute volume mount, data transmission to an iSCSI target by
a daemon, or Object Storage object integrity checks.
back-end catalog
The storage method used by the Identity service catalog service
to store and retrieve information about API endpoints that are
available to the client. Examples include an SQL database, LDAP
database, or KVS back end.
back-end store
The persistent data store used to save and retrieve information
for a service, such as lists of Object Storage objects, current state
of guest VMs, lists of user names, and so on. Also, the method that the
Image service uses to get and store VM images. Options include Object
Storage, local file system, S3, and HTTP.
backup restore and disaster recovery as a service
The OpenStack project that provides integrated tooling for
backing up, restoring, and recovering file systems,
instances, or database backups. The project name is freezer.
bandwidth
The amount of available data used by communication resources,
such as the Internet. Represents the amount of data that is used to
download things or the amount of data available to download.
barbican
Code name of the key management service for OpenStack.
bare
An Image service container format that indicates that no
container exists for the VM image.
Bare Metal service
OpenStack project that provisions bare metal, as opposed to
virtual, machines. The code name for the project is ironic.
base image
An OpenStack-provided image.
Bell-LaPadula model
A security model that focuses on data confidentiality
and controlled access to classified information.
This model divide the entities into subjects and objects.
The clearance of a subject is compared to the classification of the
object to determine if the subject is authorized for the specific access mode.
The clearance or classification scheme is expressed in terms of a lattice.
Benchmark service
OpenStack project that provides a framework for
performance analysis and benchmarking of individual
OpenStack components as well as full production OpenStack
cloud deployments. The code name of the project is rally.
Bexar
A grouped release of projects related to
OpenStack that came out in February of 2011. It
included only Compute (nova) and Object Storage (swift).
Bexar is the code name for the second release of
OpenStack. The design summit took place in
San Antonio, Texas, US, which is the county seat for Bexar county.
binary
Information that consists solely of ones and zeroes, which is
the language of computers.
bit
A bit is a single digit number that is in base of 2 (either a
zero or one). Bandwidth usage is measured in bits per second.
bits per second (BPS)
The universal measurement of how quickly data is transferred
from place to place.
block device
A device that moves data in the form of blocks. These device
nodes interface the devices, such as hard disks, CD-ROM drives, flash
drives, and other addressable regions of memory.
block migration
A method of VM live migration used by KVM to evacuate instances
from one host to another with very little downtime during a
user-initiated switchover. Does not require shared storage. Supported
by Compute.
Block Storage service
The OpenStack core project that enables management of volumes,
volume snapshots, and volume types. The project name of Block Storage
is cinder.
Block Storage API
An API on a separate endpoint for attaching,
detaching, and creating block storage for compute
VMs.
BMC
Baseboard Management Controller. The intelligence in the IPMI
architecture, which is a specialized micro-controller that is embedded
on the motherboard of a computer and acts as a server. Manages the
interface between system management software and platform
hardware.
bootable disk image
A type of VM image that exists as a single, bootable
file.
Bootstrap Protocol (BOOTP)
A network protocol used by a network client to obtain an IP
address from a configuration server. Provided in Compute through the
dnsmasq daemon when using either the FlatDHCP manager or VLAN manager
network manager.
Border Gateway Protocol (BGP)
The Border Gateway Protocol is a dynamic routing protocol
that connects autonomous systems. Considered the
backbone of the Internet, this protocol connects disparate
networks to form a larger network.
browser
Any client software that enables a computer or device to access
the Internet.
builder file
Contains configuration information that Object Storage uses to
reconfigure a ring or to re-create it from scratch after a serious
failure.
bursting
The practice of utilizing a secondary environment to
elastically build instances on-demand when the primary
environment is resource constrained.
button class
A group of related button types within horizon. Buttons to
start, stop, and suspend VMs are in one class. Buttons to associate
and disassociate floating IP addresses are in another class, and so
on.
byte
Set of bits that make up a single character; there are usually 8
bits to a byte.
CA
Certificate Authority or Certification Authority. In
cryptography, an entity that issues digital certificates. The digital
certificate certifies the ownership of a public key by the named
subject of the certificate. This enables others (relying parties) to
rely upon signatures or assertions made by the private key that
corresponds to the certified public key. In this model of trust
relationships, a CA is a trusted third party for both the subject
(owner) of the certificate and the party relying upon the certificate.
CAs are characteristic of many public key infrastructure (PKI)
schemes.
cache pruner
A program that keeps the Image service VM image cache at or
below its configured maximum size.
Cactus
An OpenStack grouped release of projects that came out in the
spring of 2011. It included Compute (nova), Object Storage (swift),
and the Image service (glance).
Cactus is a city in Texas, US and is the code name for
the third release of OpenStack. When OpenStack releases went
from three to six months long, the code name of the release
changed to match a geography nearest the previous
summit.
CADF
Cloud Auditing Data Federation (CADF) is a
specification for audit event data. CADF is
supported by OpenStack Identity.
CALL
One of the RPC primitives used by the OpenStack message queue
software. Sends a message and waits for a response.
capability
Defines resources for a cell, including CPU, storage, and
networking. Can apply to the specific services within a cell or a
whole cell.
capacity cache
A Compute back-end database table that contains the current
workload, amount of free RAM, and number of VMs running on each host.
Used to determine on which host a VM starts.
capacity updater
A notification driver that monitors VM instances and updates the
capacity cache as needed.
CAST
One of the RPC primitives used by the OpenStack message queue
software. Sends a message and does not wait for a response.
catalog
A list of API endpoints that are available to a user after
authentication with the Identity service.
catalog service
An Identity service that lists API endpoints that are available
to a user after authentication with the Identity service.
ceilometer
The project name for the Telemetry service, which is an
integrated project that provides metering and measuring facilities for
OpenStack.
cell
Provides logical partitioning of Compute resources in a child
and parent relationship. Requests are passed from parent cells to
child cells if the parent cannot provide the requested
resource.
cell forwarding
A Compute option that enables parent cells to pass resource
requests to child cells if the parent cannot provide the requested
resource.
cell manager
The Compute component that contains a list of the current
capabilities of each host within the cell and routes requests as
appropriate.
CentOS
A Linux distribution that is compatible with OpenStack.
Ceph
Massively scalable distributed storage system that consists of
an object store, block store, and POSIX-compatible distributed file
system. Compatible with OpenStack.
CephFS
The POSIX-compliant file system provided by Ceph.
certificate authority
A simple certificate authority provided by Compute for cloudpipe
VPNs and VM image decryption.
Challenge-Handshake Authentication Protocol (CHAP)
An iSCSI authentication method supported by Compute.
chance scheduler
A scheduling method used by Compute that randomly chooses an
available host from the pool.
changes since
A Compute API parameter that downloads changes to the requested
item since your last request, instead of downloading a new, fresh set
of data and comparing it against the old data.
Chef
An operating system configuration management tool supporting
OpenStack deployments.
child cell
If a requested resource such as CPU time, disk storage, or
memory is not available in the parent cell, the request is forwarded
to its associated child cells. If the child cell can fulfill the
request, it does. Otherwise, it attempts to pass the request to any of
its children.
cinder
A core OpenStack project that provides block storage services
for VMs.
CirrOS
A minimal Linux distribution designed for use as a test
image on clouds such as OpenStack.
Cisco neutron plug-in
A Networking plug-in for Cisco devices and technologies,
including UCS and Nexus.
cloud architect
A person who plans, designs, and oversees the creation of
clouds.
cloud computing
A model that enables access to a shared pool of configurable
computing resources, such as networks, servers, storage, applications,
and services, that can be rapidly provisioned and released with
minimal management effort or service provider interaction.
cloud controller
Collection of Compute components that represent the global state
of the cloud; talks to services, such as Identity authentication,
Object Storage, and node/storage workers through a
queue.
cloud controller node
A node that runs network, volume, API, scheduler, and image
services. Each service may be broken out into separate nodes for
scalability or availability.
Cloud Data Management Interface (CDMI)
SINA standard that defines a RESTful API for managing objects in
the cloud, currently unsupported in OpenStack.
Cloud Infrastructure Management Interface (CIMI)
An in-progress specification for cloud management. Currently
unsupported in OpenStack.
cloud-init
A package commonly installed in VM images that performs
initialization of an instance after boot using information that it
retrieves from the metadata service, such as the SSH public key and
user data.
cloudadmin
One of the default roles in the Compute RBAC system. Grants
complete system access.
Cloudbase-Init
A Windows project providing guest initialization features,
similar to cloud-init.
cloudpipe
A compute service that creates VPNs on a per-project
basis.
cloudpipe image
A pre-made VM image that serves as a cloudpipe server.
Essentially, OpenVPN running on Linux.
Clustering service
The OpenStack project that OpenStack project that implements
clustering services and libraries for the management of
groups of homogeneous objects exposed by other OpenStack
services. The project name of Clustering service is
senlin.
CMDB
Configuration Management Database.
congress
OpenStack project that provides the Governance service.
command filter
Lists allowed commands within the Compute rootwrap
facility.
Common Internet File System (CIFS)
A file sharing protocol. It is a public or open variation of the
original Server Message Block (SMB) protocol developed and used by
Microsoft. Like the SMB protocol, CIFS runs at a higher level and uses
the TCP/IP protocol.
community project
A project that is not officially endorsed by the OpenStack
Foundation. If the project is successful enough, it might be elevated
to an incubated project and then to a core project, or it might be
merged with the main code trunk.
compression
Reducing the size of files by special encoding, the file can be
decompressed again to its original content. OpenStack supports
compression at the Linux file system level but does not support
compression for things such as Object Storage objects or Image service
VM images.
Compute service
The OpenStack core project that provides compute services. The
project name of Compute service is nova.
Compute API
The nova-api daemon
provides access to nova services. Can communicate with other APIs,
such as the Amazon EC2 API.
compute controller
The Compute component that chooses suitable hosts on which to
start VM instances.
compute host
Physical host dedicated to running compute nodes.
compute node
A node that runs the nova-compute daemon that manages VM
instances that provide a wide
range of services, such as web applications and analytics.
Compute service
Name for the Compute component that manages VMs.
compute worker
The Compute component that runs on each compute node and manages
the VM instance lifecycle, including run, reboot, terminate,
attach/detach volumes, and so on. Provided by the nova-compute daemon.
concatenated object
A set of segment objects that Object Storage combines and sends
to the client.
conductor
In Compute, conductor is the process that proxies database
requests from the compute process. Using conductor improves security
because compute nodes do not need direct access to the
database.
consistency window
The amount of time it takes for a new Object Storage object to
become accessible to all clients.
console log
Contains the output from a Linux VM console in Compute.
container
Organizes and stores objects in Object Storage. Similar to the
concept of a Linux directory but cannot be nested. Alternative term
for an Image service container format.
container auditor
Checks for missing replicas or incorrect objects in specified
Object Storage containers through queries to the SQLite back-end
database.
container database
A SQLite database that stores Object Storage containers and
container metadata. The container server accesses this
database.
container format
A wrapper used by the Image service that contains a VM image and
its associated metadata, such as machine state, OS disk size, and so
on.
container server
An Object Storage server that manages containers.
Containers service
OpenStack project that provides a set of services for
management of application containers in a multi-tenant cloud
environment. The code name of the project name is magnum.
container service
The Object Storage component that provides container services,
such as create, delete, list, and so on.
content delivery network (CDN)
A content delivery network is a specialized network that is
used to distribute content to clients, typically located
close to the client for increased performance.
controller node
Alternative term for a cloud controller node.
core API
Depending on context, the core API is either the OpenStack API
or the main API of a specific core project, such as Compute,
Networking, Image service, and so on.
core service
An official OpenStack service defined as core by
DefCore Committee. Currently, consists of
Block Storage service (cinder), Compute service (nova),
Identity service (keystone), Image service (glance),
Networking service (neutron), and Object Storage service (swift).
cost
Under the Compute distributed scheduler, this is calculated by
looking at the capabilities of each host relative to the flavor of the
VM instance being requested.
credentials
Data that is only known to or accessible by a user and
used to verify that the user is who he says he is.
Credentials are presented to the server during
authentication. Examples include a password, secret key,
digital certificate, and fingerprint.
Cross-Origin Resource Sharing (CORS)
A mechanism that allows many resources (for example,
fonts, JavaScript) on a web page to be requested from
another domain outside the domain from which the resource
originated. In particular, JavaScript's AJAX calls can use
the XMLHttpRequest mechanism.
Crowbar
An open source community project by Dell that aims to provide
all necessary services to quickly deploy clouds.
current workload
An element of the Compute capacity cache that is calculated
based on the number of build, snapshot, migrate, and resize operations
currently in progress on a given host.
customer
Alternative term for tenant.
customization module
A user-created Python module that is loaded by horizon to change
the look and feel of the dashboard.
daemon
A process that runs in the background and waits for requests.
May or may not listen on a TCP or UDP port. Do not confuse with a
worker.
DAC
Discretionary access control. Governs the ability of subjects to
access objects, while enabling users to make policy decisions and
assign security attributes. The traditional UNIX system of users,
groups, and read-write-execute permissions is an example of
DAC.
Dashboard
The web-based management interface for OpenStack. An alternative
name for horizon.
data encryption
Both Image service and Compute support encrypted virtual machine
(VM) images (but not instances). In-transit data encryption is
supported in OpenStack using technologies such as HTTPS, SSL, TLS, and
SSH. Object Storage does not support object encryption at the
application level but may support storage that uses disk encryption.
database ID
A unique ID given to each replica of an Object Storage
database.
database replicator
An Object Storage component that copies changes in the account,
container, and object databases to other nodes.
Database service
An integrated project that provide scalable and reliable
Cloud Database-as-a-Service functionality for both
relational and non-relational database engines. The project
name of Database service is trove.
Data Processing service
OpenStack project that provides a scalable
data-processing stack and associated management
interfaces. The code name for the project is sahara.
data store
A database engine supported by the Database service.
deallocate
The process of removing the association between a floating IP
address and a fixed IP address. Once this association is removed, the
floating IP returns to the address pool.
Debian
A Linux distribution that is compatible with OpenStack.
deduplication
The process of finding duplicate data at the disk block, file,
and/or object level to minimize storage use—currently unsupported
within OpenStack.
default panel
The default panel that is displayed when a user accesses the
horizon dashboard.
default tenant
New users are assigned to this tenant if no tenant is specified
when a user is created.
default token
An Identity service token that is not associated with a specific
tenant and is exchanged for a scoped token.
delayed delete
An option within Image service so that an image is deleted after
a predefined number of seconds instead of immediately.
delivery mode
Setting for the Compute RabbitMQ message delivery mode; can be
set to either transient or persistent.
denial of service (DoS)
Denial of service (DoS) is a short form for
denial-of-service attack. This is a malicious attempt to
prevent legitimate users from using a service.
deprecated auth
An option within Compute that enables administrators to create
and manage users through the ``nova-manage`` command as
opposed to using the Identity service.
designate
Code name for the DNS service project for OpenStack.
Desktop-as-a-Service
A platform that provides a suite of desktop environments
that users access to receive a desktop experience from
any location. This may provide general use, development, or
even homogeneous testing environments.
developer
One of the default roles in the Compute RBAC system and the
default role assigned to a new user.
device ID
Maps Object Storage partitions to physical storage
devices.
device weight
Distributes partitions proportionately across Object Storage
devices based on the storage capacity of each device.
DevStack
Community project that uses shell scripts to quickly build
complete OpenStack development environments.
DHCP
Dynamic Host Configuration Protocol. A network protocol that
configures devices that are connected to a network so that they can
communicate on that network by using the Internet Protocol (IP). The
protocol is implemented in a client-server model where DHCP clients
request configuration data, such as an IP address, a default route,
and one or more DNS server addresses from a DHCP server.
DHCP agent
OpenStack Networking agent that provides DHCP services
for virtual networks.
Diablo
A grouped release of projects related to OpenStack that came out
in the fall of 2011, the fourth release of OpenStack. It included
Compute (nova 2011.3), Object Storage (swift 1.4.3), and the Image
service (glance).
Diablo is the code name for the fourth release of
OpenStack. The design summit took place in
the Bay Area near Santa Clara,
California, US and Diablo is a nearby city.
direct consumer
An element of the Compute RabbitMQ that comes to life when a RPC
call is executed. It connects to a direct exchange through a unique
exclusive queue, sends the message, and terminates.
direct exchange
A routing table that is created within the Compute RabbitMQ
during RPC calls; one is created for each RPC call that is
invoked.
direct publisher
Element of RabbitMQ that provides a response to an incoming MQ
message.
disassociate
The process of removing the association between a floating IP
address and fixed IP and thus returning the floating IP address to the
address pool.
disk encryption
The ability to encrypt data at the file system, disk partition,
or whole-disk level. Supported within Compute VMs.
disk format
The underlying format that a disk image for a VM is stored as
within the Image service back-end store. For example, AMI, ISO, QCOW2,
VMDK, and so on.
dispersion
In Object Storage, tools to test and ensure dispersion of
objects and containers to ensure fault tolerance.
distributed virtual router (DVR)
Mechanism for highly-available multi-host routing when using
OpenStack Networking (neutron).
Django
A web framework used extensively in horizon.
DNS
Domain Name System. A hierarchical and distributed naming system
for computers, services, and resources connected to the Internet or a
private network. Associates a human-friendly names to IP
addresses.
DNS record
A record that specifies information about a particular domain
and belongs to the domain.
DNS service
OpenStack project that provides scalable, on demand, self
service access to authoritative DNS services, in a
technology-agnostic manner. The code name for the project is
designate.
dnsmasq
Daemon that provides DNS, DHCP, BOOTP, and TFTP services for
virtual networks.
domain
An Identity API v3 entity. Represents a collection of
projects, groups and users that defines administrative boundaries for
managing OpenStack Identity entities.
On the Internet, separates a website from other sites. Often,
the domain name has two or more parts that are separated by dots.
For example, yahoo.com, usa.gov, harvard.edu, or
mail.yahoo.com.
Also, a domain is an entity or container of all DNS-related
information containing one or more records.
Domain Name System (DNS)
A system by which Internet domain name-to-address and
address-to-name resolutions are determined.
DNS helps navigate the Internet by translating the IP address
into an address that is easier to remember. For example, translating
111.111.111.1 into www.yahoo.com.
All domains and their components, such as mail servers, utilize
DNS to resolve to the appropriate locations. DNS servers are usually
set up in a master-slave relationship such that failure of the master
invokes the slave. DNS servers might also be clustered or replicated
such that changes made to one DNS server are automatically propagated
to other active servers.
In Compute, the support that enables associating DNS entries
with floating IP addresses, nodes, or cells so that hostnames are
consistent across reboots.
download
The transfer of data, usually in the form of files, from one
computer to another.
DRTM
Dynamic root of trust measurement.
durable exchange
The Compute RabbitMQ message exchange that remains active when
the server restarts.
durable queue
A Compute RabbitMQ message queue that remains active when the
server restarts.
Dynamic Host Configuration Protocol (DHCP)
A method to automatically configure networking for a host at
boot time. Provided by both Networking and Compute.
Dynamic HyperText Markup Language (DHTML)
Pages that use HTML, JavaScript, and Cascading Style Sheets to
enable users to interact with a web page or show simple
animation.
east-west traffic
Network traffic between servers in the same cloud or data center.
See also north-south traffic.
EBS boot volume
An Amazon EBS storage volume that contains a bootable VM image,
currently unsupported in OpenStack.
ebtables
Filtering tool for a Linux bridging firewall, enabling
filtering of network traffic passing through a Linux bridge.
Used in Compute along with arptables, iptables, and ip6tables
to ensure isolation of network communications.
EC2
The Amazon commercial compute product, similar to
Compute.
EC2 access key
Used along with an EC2 secret key to access the Compute EC2
API.
EC2 API
OpenStack supports accessing the Amazon EC2 API through
Compute.
EC2 Compatibility API
A Compute component that enables OpenStack to communicate with
Amazon EC2.
EC2 secret key
Used along with an EC2 access key when communicating with the
Compute EC2 API; used to digitally sign each request.
Elastic Block Storage (EBS)
The Amazon commercial block storage product.
encryption
OpenStack supports encryption technologies such as HTTPS, SSH,
SSL, TLS, digital certificates, and data encryption.
endpoint
See API endpoint.
endpoint registry
Alternative term for an Identity service catalog.
encapsulation
The practice of placing one packet type within another for
the purposes of abstracting or securing data. Examples
include GRE, MPLS, or IPsec.
endpoint template
A list of URL and port number endpoints that indicate where a
service, such as Object Storage, Compute, Identity, and so on, can be
accessed.
entity
Any piece of hardware or software that wants to connect to the
network services provided by Networking, the network connectivity
service. An entity can make use of Networking by implementing a
VIF.
ephemeral image
A VM image that does not save changes made to its volumes and
reverts them to their original state after the instance is
terminated.
ephemeral volume
Volume that does not save the changes made to it and reverts to
its original state when the current user relinquishes control.
Essex
A grouped release of projects related to OpenStack that came out
in April 2012, the fifth release of OpenStack. It included Compute
(nova 2012.1), Object Storage (swift 1.4.8), Image (glance), Identity
(keystone), and Dashboard (horizon).
Essex is the code name for the fifth release of
OpenStack. The design summit took place in
Boston, Massachusetts, US and Essex is a nearby city.
ESXi
An OpenStack-supported hypervisor.
ETag
MD5 hash of an object within Object Storage, used to ensure data
integrity.
euca2ools
A collection of command-line tools for administering VMs; most
are compatible with OpenStack.
Eucalyptus Kernel Image (EKI)
Used along with an ERI to create an EMI.
Eucalyptus Machine Image (EMI)
VM image container format supported by Image service.
Eucalyptus Ramdisk Image (ERI)
Used along with an EKI to create an EMI.
evacuate
The process of migrating one or all virtual machine (VM)
instances from one host to another, compatible with both shared
storage live migration and block migration.
exchange
Alternative term for a RabbitMQ message exchange.
exchange type
A routing algorithm in the Compute RabbitMQ.
exclusive queue
Connected to by a direct consumer in RabbitMQ—Compute, the
message can be consumed only by the current connection.
extended attributes (xattr)
File system option that enables storage of additional
information beyond owner, group, permissions, modification time, and
so on. The underlying Object Storage file system must support extended
attributes.
extension
Alternative term for an API extension or plug-in. In the context
of Identity service, this is a call that is specific to the
implementation, such as adding support for OpenID.
external network
A network segment typically used for instance Internet
access.
extra specs
Specifies additional requirements when Compute determines where
to start a new instance. Examples include a minimum amount of network
bandwidth or a GPU.
FakeLDAP
An easy method to create a local LDAP directory for testing
Identity and Compute. Requires Redis.
fan-out exchange
Within RabbitMQ and Compute, it is the messaging interface that
is used by the scheduler service to receive capability messages from
the compute, volume, and network nodes.
federated identity
A method to establish trusts between identity providers and the
OpenStack cloud.
Fedora
A Linux distribution compatible with OpenStack.
Fibre Channel
Storage protocol similar in concept to TCP/IP; encapsulates SCSI
commands and data.
Fibre Channel over Ethernet (FCoE)
The fibre channel protocol tunneled within Ethernet.
fill-first scheduler
The Compute scheduling method that attempts to fill a host with
VMs rather than starting new VMs on a variety of hosts.
filter
The step in the Compute scheduling process when hosts that
cannot run VMs are eliminated and not chosen.
firewall
Used to restrict communications between hosts and/or nodes,
implemented in Compute using iptables, arptables, ip6tables, and
ebtables.
FWaaS
A Networking extension that provides perimeter firewall
functionality.
fixed IP address
An IP address that is associated with the same instance each
time that instance boots, is generally not accessible to end users or
the public Internet, and is used for management of the
instance.
Flat Manager
The Compute component that gives IP addresses to authorized
nodes and assumes DHCP, DNS, and routing configuration and services
are provided by something else.
flat mode injection
A Compute networking method where the OS network configuration
information is injected into the VM image before the instance
starts.
flat network
Virtual network type that uses neither VLANs nor tunnels to
segregate tenant traffic. Each flat network typically requires
a separate underlying physical interface defined by bridge
mappings. However, a flat network can contain multiple
subnets.
FlatDHCP Manager
The Compute component that provides dnsmasq (DHCP, DNS, BOOTP,
TFTP) and radvd (routing) services.
flavor
Alternative term for a VM instance type.
flavor ID
UUID for each Compute or Image service VM flavor or instance
type.
floating IP address
An IP address that a project can associate with a VM so that the
instance has the same public IP address each time that it boots. You
create a pool of floating IP addresses and assign them to instances as
they are launched to maintain a consistent IP address for maintaining
DNS assignment.
Folsom
A grouped release of projects related to OpenStack that came out
in the fall of 2012, the sixth release of OpenStack. It includes
Compute (nova), Object Storage (swift), Identity (keystone),
Networking (neutron), Image service (glance), and Volumes or Block
Storage (cinder).
Folsom is the code name for the sixth release of
OpenStack. The design summit took place in
San Francisco, California, US and Folsom is a nearby city.
FormPost
Object Storage middleware that uploads (posts) an image through
a form on a web page.
freezer
OpenStack project that provides backup restore and disaster
recovery as a service.
front end
The point where a user interacts with a service; can be an API
endpoint, the horizon dashboard, or a command-line tool.
gateway
An IP address, typically assigned to a router, that
passes network traffic between different networks.
generic receive offload (GRO)
Feature of certain network interface drivers that
combines many smaller received packets into a large packet
before delivery to the kernel IP stack.
generic routing encapsulation (GRE)
Protocol that encapsulates a wide variety of network
layer protocols inside virtual point-to-point links.
glance
A core project that provides the OpenStack Image service.
glance API server
Processes client requests for VMs, updates Image service
metadata on the registry server, and communicates with the store
adapter to upload VM images from the back-end store.
glance registry
Alternative term for the Image service image registry.
global endpoint template
The Identity service endpoint template that contains services
available to all tenants.
GlusterFS
A file system designed to aggregate NAS hosts, compatible with
OpenStack.
golden image
A method of operating system installation where a finalized disk
image is created and then used by all nodes without
modification.
Governance service
OpenStack project to provide Governance-as-a-Service across
any collection of cloud services in order to monitor,
enforce, and audit policy over dynamic infrastructure. The
code name for the project is congress.
Graphic Interchange Format (GIF)
A type of image file that is commonly used for animated images
on web pages.
Graphics Processing Unit (GPU)
Choosing a host based on the existence of a GPU is currently
unsupported in OpenStack.
Green Threads
The cooperative threading model used by Python; reduces race
conditions and only context switches when specific library calls are
made. Each OpenStack service is its own thread.
Grizzly
The code name for the seventh release of
OpenStack. The design summit took place in
San Diego, California, US and Grizzly is an element of the state flag of
California.
Group
An Identity v3 API entity. Represents a collection of users that is
owned by a specific domain.
guest OS
An operating system instance running under the control of a
hypervisor.
Hadoop
Apache Hadoop is an open source software framework that supports
data-intensive distributed applications.
Hadoop Distributed File System (HDFS)
A distributed, highly fault-tolerant file system designed to run
on low-cost commodity hardware.
handover
An object state in Object Storage where a new replica of the
object is automatically created due to a drive failure.
hard reboot
A type of reboot where a physical or virtual power button is
pressed as opposed to a graceful, proper shutdown of the operating
system.
Havana
The code name for the eighth release of OpenStack. The
design summit took place in Portland, Oregon, US and Havana is
an unincorporated community in Oregon.
heat
An integrated project that aims to orchestrate multiple cloud
applications for OpenStack.
Heat Orchestration Template (HOT)
Heat input in the format native to OpenStack.
health monitor
Determines whether back-end members of a VIP pool can
process a request. A pool can have several health monitors
associated with it. When a pool has several monitors
associated with it, all monitors check each member of the
pool. All monitors must declare a member to be healthy for
it to stay active.
high availability (HA)
A high availability system design approach and associated
service implementation ensures that a prearranged level of
operational performance will be met during a contractual
measurement period. High availability systems seeks to
minimize system downtime and data loss.
horizon
OpenStack project that provides a dashboard, which is a web
interface.
horizon plug-in
A plug-in for the OpenStack dashboard (horizon).
host
A physical computer, not a VM instance (node).
host aggregate
A method to further subdivide availability zones into hypervisor
pools, a collection of common hosts.
Host Bus Adapter (HBA)
Device plugged into a PCI slot, such as a fibre channel or
network card.
hybrid cloud
A hybrid cloud is a composition of two or more clouds
(private, community or public) that remain distinct entities
but are bound together, offering the benefits of multiple
deployment models. Hybrid cloud can also mean the ability
to connect colocation, managed and/or dedicated services
with cloud resources.
Hyper-V
One of the hypervisors supported by OpenStack.
hyperlink
Any kind of text that contains a link to some other site,
commonly found in documents where clicking on a word or words opens up
a different website.
Hypertext Transfer Protocol (HTTP)
An application protocol for distributed, collaborative,
hypermedia information systems. It is the foundation of data
communication for the World Wide Web. Hypertext is structured
text that uses logical links (hyperlinks) between nodes containing
text. HTTP is the protocol to exchange or transfer hypertext.
Hypertext Transfer Protocol Secure (HTTPS)
An encrypted communications protocol for secure communication
over a computer network, with especially wide deployment on the
Internet. Technically, it is not a protocol in and of itself;
rather, it is the result of simply layering the Hypertext Transfer
Protocol (HTTP) on top of the TLS or SSL protocol, thus adding the
security capabilities of TLS or SSL to standard HTTP communications.
most OpenStack API endpoints and many inter-component communications
support HTTPS communication.
hypervisor
Software that arbitrates and controls VM access to the actual
underlying hardware.
hypervisor pool
A collection of hypervisors grouped together through host
aggregates.
IaaS
Infrastructure-as-a-Service. IaaS is a provisioning model in
which an organization outsources physical components of a data center,
such as storage, hardware, servers, and networking components. A
service provider owns the equipment and is responsible for housing,
operating and maintaining it. The client typically pays on a per-use
basis. IaaS is a model for providing cloud services.
Icehouse
The code name for the ninth release of OpenStack. The
design summit took place in Hong Kong and Ice House is a
street in that city.
ICMP
Internet Control Message Protocol, used by network
devices for control messages. For example,
:command:`ping` uses ICMP to test
connectivity.
ID number
Unique numeric ID associated with each user in Identity,
conceptually similar to a Linux or LDAP UID.
Identity API
Alternative term for the Identity service API.
Identity back end
The source used by Identity service to retrieve user
information; an OpenLDAP server, for example.
identity provider
A directory service, which allows users to login with a user
name and password. It is a typical source of authentication
tokens.
Identity service
The OpenStack core project that provides a central directory of
users mapped to the OpenStack services they can access. It also
registers endpoints for OpenStack services. It acts as a common
authentication system. The project name of Identity is
keystone.
Identity service API
The API used to access the OpenStack Identity service provided
through keystone.
IDS
Intrusion Detection System.
image
A collection of files for a specific operating system (OS) that
you use to create or rebuild a server. OpenStack provides pre-built
images. You can also create custom images, or snapshots, from servers
that you have launched. Custom images can be used for data backups or
as "gold" images for additional servers.
Image API
The Image service API endpoint for management of VM
images.
image cache
Used by Image service to obtain images on the local host rather
than re-downloading them from the image server each time one is
requested.
image ID
Combination of a URI and UUID used to access Image service VM
images through the image API.
image membership
A list of tenants that can access a given VM image within Image
service.
image owner
The tenant who owns an Image service virtual machine
image.
image registry
A list of VM images that are available through Image
service.
Image service
An OpenStack core project that provides discovery, registration,
and delivery services for disk and server images. The project name of
the Image service is glance.
Image service API
Alternative name for the glance image API.
image status
The current status of a VM image in Image service, not to be
confused with the status of a running instance.
image store
The back-end store used by Image service to store VM images,
options include Object Storage, local file system, S3, or HTTP.
image UUID
UUID used by Image service to uniquely identify each VM
image.
incubated project
A community project may be elevated to this status and is then
promoted to a core project.
ingress filtering
The process of filtering incoming network traffic. Supported by
Compute.
INI
The OpenStack configuration files use an INI format to
describe options and their values. It consists of sections
and key value pairs.
injection
The process of putting a file into a virtual machine image
before the instance is started.
instance
A running VM, or a VM in a known state such as suspended, that
can be used like a hardware server.
instance ID
Alternative term for instance UUID.
instance state
The current state of a guest VM image.
instance tunnels network
A network segment used for instance traffic tunnels
between compute nodes and the network node.
instance type
Describes the parameters of the various virtual machine images
that are available to users; includes parameters such as CPU, storage,
and memory. Alternative term for flavor.
instance type ID
Alternative term for a flavor ID.
instance UUID
Unique ID assigned to each guest VM instance.
interface
A physical or virtual device that provides connectivity
to another device or medium.
interface ID
Unique ID for a Networking VIF or vNIC in the form of a
UUID.
Internet protocol (IP)
Principal communications protocol in the internet protocol
suite for relaying datagrams across network boundaries.
Internet Service Provider (ISP)
Any business that provides Internet access to individuals or
businesses.
Internet Small Computer System Interface (iSCSI)
Storage protocol that encapsulates SCSI frames for transport
over IP networks.
ironic
OpenStack project that provisions bare metal, as opposed to
virtual, machines.
IOPS
IOPS (Input/Output Operations Per Second) are a common
performance measurement used to benchmark computer storage
devices like hard disk drives, solid state drives, and
storage area networks.
IP address
Number that is unique to every computer system on the Internet.
Two versions of the Internet Protocol (IP) are in use for addresses:
IPv4 and IPv6.
IP Address Management (IPAM)
The process of automating IP address allocation, deallocation,
and management. Currently provided by Compute, melange, and
Networking.
IPL
Initial Program Loader.
IPMI
Intelligent Platform Management Interface. IPMI is a
standardized computer system interface used by system administrators
for out-of-band management of computer systems and monitoring of their
operation. In layman's terms, it
is a way to manage a computer using a direct network connection,
whether it is turned on or not; connecting to the hardware rather than
an operating system or login shell.
ip6tables
Tool used to set up, maintain, and inspect the tables of IPv6
packet filter rules in the Linux kernel. In OpenStack Compute,
ip6tables is used along with arptables, ebtables, and iptables to
create firewalls for both nodes and VMs.
ipset
Extension to iptables that allows creation of firewall rules
that match entire "sets" of IP addresses simultaneously. These
sets reside in indexed data structures to increase efficiency,
particularly on systems with a large quantity of rules.
iptables
Used along with arptables and ebtables, iptables create
firewalls in Compute. iptables are the tables provided by the Linux
kernel firewall (implemented as different Netfilter modules) and the
chains and rules it stores. Different kernel modules and programs are
currently used for different protocols: iptables applies to IPv4,
ip6tables to IPv6, arptables to ARP, and ebtables to Ethernet frames.
Requires root privilege to manipulate.
IQN
iSCSI Qualified Name (IQN) is the format most commonly used
for iSCSI names, which uniquely identify nodes in an iSCSI network.
All IQNs follow the pattern iqn.yyyy-mm.domain:identifier, where
'yyyy-mm' is the year and month in which the domain was registered,
'domain' is the reversed domain name of the issuing organization, and
'identifier' is an optional string which makes each IQN under the same
domain unique. For example, 'iqn.2015-10.org.openstack.408ae959bce1'.
iSCSI
The SCSI disk protocol tunneled within Ethernet, supported by
Compute, Object Storage, and Image service.
ISO9660
One of the VM image disk formats supported by Image
service.
itsec
A default role in the Compute RBAC system that can quarantine an
instance in any project.
Java
A programming language that is used to create systems that
involve more than one computer by way of a network.
JavaScript
A scripting language that is used to build web pages.
JavaScript Object Notation (JSON)
One of the supported response formats in OpenStack.
Jenkins
Tool used to run jobs automatically for OpenStack
development.
jumbo frame
Feature in modern Ethernet networks that supports frames up to
approximately 9000 bytes.
Juno
The code name for the tenth release of OpenStack. The
design summit took place in Atlanta, Georgia, US and Juno is
an unincorporated community in Georgia.
Kerberos
A network authentication protocol which works on the basis of
tickets. Kerberos allows nodes communication over a non-secure
network, and allows nodes to prove their identity to one another in a
secure manner.
kernel-based VM (KVM)
An OpenStack-supported hypervisor. KVM is a full
virtualization solution for Linux on x86 hardware containing
virtualization extensions (Intel VT or AMD-V), ARM, IBM
Power, and IBM zSeries. It consists of a loadable kernel
module, that provides the core virtualization infrastructure
and a processor specific module.
Key Manager service
OpenStack project that produces a secret storage and
generation system capable of providing key management for
services wishing to enable encryption features. The code name
of the project is barbican.
keystone
The project that provides OpenStack Identity services.
Kickstart
A tool to automate system configuration and installation on Red
Hat, Fedora, and CentOS-based Linux distributions.
Kilo
The code name for the eleventh release of OpenStack. The
design summit took place in Paris, France. Due to delays in the name
selection, the release was known only as K. Because ``k`` is the
unit symbol for kilo and the reference artifact is stored near Paris
in the Pavillon de Breteuil in Sèvres, the community chose Kilo as
the release name.
large object
An object within Object Storage that is larger than 5 GB.
Launchpad
The collaboration site for OpenStack.
Layer-2 network
Term used in the OSI network architecture for the data link
layer. The data link layer is responsible for media access
control, flow control and detecting and possibly correcting
errors that may occur in the physical layer.
Layer-3 network
Term used in the OSI network architecture for the network
layer. The network layer is responsible for packet
forwarding including routing from one node to another.
Layer-2 (L2) agent
OpenStack Networking agent that provides layer-2
connectivity for virtual networks.
Layer-3 (L3) agent
OpenStack Networking agent that provides layer-3
(routing) services for virtual networks.
Liberty
The code name for the twelfth release of OpenStack. The
design summit took place in Vancouver, Canada and Liberty is
the name of a village in the Canadian province of
Saskatchewan.
libvirt
Virtualization API library used by OpenStack to interact with
many of its supported hypervisors.
Lightweight Directory Access Protocol (LDAP)
An application protocol for accessing and maintaining distributed
directory information services over an IP network.
Linux bridge
Software that enables multiple VMs to share a single physical
NIC within Compute.
Linux Bridge neutron plug-in
Enables a Linux bridge to understand a Networking port,
interface attachment, and other abstractions.
Linux containers (LXC)
An OpenStack-supported hypervisor.
live migration
The ability within Compute to move running virtual machine
instances from one host to another with only a small service
interruption during switchover.
load balancer
A load balancer is a logical device that belongs to a cloud
account. It is used to distribute workloads between multiple back-end
systems or services, based on the criteria defined as part of its
configuration.
load balancing
The process of spreading client requests between two or more
nodes to improve performance and availability.
LBaaS
Enables Networking to distribute incoming requests evenly
between designated instances.
Logical Volume Manager (LVM)
Provides a method of allocating space on mass-storage
devices that is more flexible than conventional partitioning
schemes.
magnum
Code name for the OpenStack project that provides the
Containers Service.
management API
Alternative term for an admin API.
management network
A network segment used for administration, not accessible to the
public Internet.
manager
Logical groupings of related code, such as the Block Storage
volume manager or network manager.
manifest
Used to track segments of a large object within Object
Storage.
manifest object
A special Object Storage object that contains the manifest for a
large object.
manila
OpenStack project that provides shared file systems as
service to applications.
maximum transmission unit (MTU)
Maximum frame or packet size for a particular network
medium. Typically 1500 bytes for Ethernet networks.
mechanism driver
A driver for the Modular Layer 2 (ML2) neutron plug-in that
provides layer-2 connectivity for virtual instances. A
single OpenStack installation can use multiple mechanism
drivers.
melange
Project name for OpenStack Network Information Service. To be
merged with Networking.
membership
The association between an Image service VM image and a tenant.
Enables images to be shared with specified tenants.
membership list
A list of tenants that can access a given VM image within Image
service.
memcached
A distributed memory object caching system that is used by
Object Storage for caching.
memory overcommit
The ability to start new VM instances based on the actual memory
usage of a host, as opposed to basing the decision on the amount of
RAM each running instance thinks it has available. Also known as RAM
overcommit.
message broker
The software package used to provide AMQP messaging capabilities
within Compute. Default package is RabbitMQ.
message bus
The main virtual communication line used by all AMQP messages
for inter-cloud communications within Compute.
message queue
Passes requests from clients to the appropriate workers and
returns the output to the client after the job completes.
Message service
OpenStack project that aims to produce an OpenStack
messaging service that affords a variety of distributed
application patterns in an efficient, scalable and
highly-available manner, and to create and maintain associated
Python libraries and documentation. The code name for the
project is zaqar.
Metadata agent
OpenStack Networking agent that provides metadata
services for instances.
Meta-Data Server (MDS)
Stores CephFS metadata.
migration
The process of moving a VM instance from one host to
another.
mistral
OpenStack project that provides the Workflow service.
Mitaka
The code name for the thirteenth release of OpenStack.
The design summit took place in Tokyo, Japan. Mitaka
is a city in Tokyo.
monasca
OpenStack project that provides a Monitoring service.
multi-host
High-availability mode for legacy (nova) networking.
Each compute node handles NAT and DHCP and acts as a gateway
for all of the VMs on it. A networking failure on one compute
node doesn't affect VMs on other compute nodes.
multinic
Facility in Compute that allows each virtual machine instance to
have more than one VIF connected to it.
murano
OpenStack project that provides an Application catalog.
Modular Layer 2 (ML2) neutron plug-in
Can concurrently use multiple layer-2 networking technologies,
such as 802.1Q and VXLAN, in Networking.
Monitor (LBaaS)
LBaaS feature that provides availability monitoring using the
``ping`` command, TCP, and HTTP/HTTPS GET.
Monitor (Mon)
A Ceph component that communicates with external clients, checks
data state and consistency, and performs quorum functions.
Monitoring
The OpenStack project that provides a multi-tenant, highly
scalable, performant, fault-tolerant Monitoring-as-a-Service
solution for metrics, complex event processing, and logging.
It builds an extensible platform for advanced monitoring
services that can be used by both operators and tenants to
gain operational insight and visibility, ensuring
availability and stability. The project name is monasca.
multi-factor authentication
Authentication method that uses two or more credentials, such as
a password and a private key. Currently not supported in
Identity.
MultiNic
Facility in Compute that enables a virtual machine instance to
have more than one VIF connected to it.
Nebula
Released as open source by NASA in 2010 and is the basis for
Compute.
netadmin
One of the default roles in the Compute RBAC system. Enables the
user to allocate publicly accessible IP addresses to instances and
change firewall rules.
NetApp volume driver
Enables Compute to communicate with NetApp storage devices
through the NetApp OnCommand
Provisioning Manager.
network
A virtual network that provides connectivity between entities.
For example, a collection of virtual ports that share network
connectivity. In Networking terminology, a network is always a layer-2
network.
NAT
Network Address Translation; Process of modifying IP address
information while in transit. Supported by Compute and
Networking.
network controller
A Compute daemon that orchestrates the network configuration of
nodes, including IP addresses, VLANs, and bridging. Also manages
routing for both public and private networks.
Network File System (NFS)
A method for making file systems available over the network.
Supported by OpenStack.
network ID
Unique ID assigned to each network segment within Networking.
Same as network UUID.
network manager
The Compute component that manages various network components,
such as firewall rules, IP address allocation, and so on.
network namespace
Linux kernel feature that provides independent virtual
networking instances on a single host with separate routing
tables and interfaces. Similar to virtual routing and forwarding
(VRF) services on physical network equipment.
network node
Any compute node that runs the network worker daemon.
network segment
Represents a virtual, isolated OSI layer-2 subnet in
Networking.
Newton
The code name for the fourteenth release of OpenStack. The
design summit will take place in Austin, Texas, US. The
release is named after "Newton House" which is located at
1013 E. Ninth St., Austin, TX. which is listed on the
National Register of Historic Places.
NTP
Network Time Protocol; Method of keeping a clock for a host or
node correct via communication with a trusted, accurate time
source.
network UUID
Unique ID for a Networking network segment.
network worker
The ``nova-network`` worker daemon; provides
services such as giving an IP address to a booting nova
instance.
Networking service
A core OpenStack project that provides a network connectivity
abstraction layer to OpenStack Compute. The project name of Networking
is neutron.
Networking API
API used to access OpenStack Networking. Provides an extensible
architecture to enable custom plug-in creation.
neutron
A core OpenStack project that provides a network connectivity
abstraction layer to OpenStack Compute.
neutron API
An alternative name for Networking API.
neutron manager
Enables Compute and Networking integration, which enables
Networking to perform network management for guest VMs.
neutron plug-in
Interface within Networking that enables organizations to create
custom plug-ins for advanced features, such as QoS, ACLs, or
IDS.
Nexenta volume driver
Provides support for NexentaStor devices in Compute.
No ACK
Disables server-side message acknowledgment in the Compute
RabbitMQ. Increases performance but decreases reliability.
node
A VM instance that runs on a host.
non-durable exchange
Message exchange that is cleared when the service restarts. Its
data is not written to persistent storage.
non-durable queue
Message queue that is cleared when the service restarts. Its
data is not written to persistent storage.
non-persistent volume
Alternative term for an ephemeral volume.
north-south traffic
Network traffic between a user or client (north) and a
server (south), or traffic into the cloud (south) and
out of the cloud (north). See also east-west traffic.
nova
OpenStack project that provides compute services.
Nova API
Alternative term for the Compute API.
nova-network
A Compute component that manages IP address allocation,
firewalls, and other network-related tasks. This is the legacy
networking option and an alternative to Networking.
object
A BLOB of data held by Object Storage; can be in any
format.
object auditor
Opens all objects for an object server and verifies the MD5
hash, size, and metadata for each object.
object expiration
A configurable option within Object Storage to automatically
delete objects after a specified amount of time has passed or a
certain date is reached.
object hash
Uniquely ID for an Object Storage object.
object path hash
Used by Object Storage to determine the location of an object in
the ring. Maps objects to partitions.
object replicator
An Object Storage component that copies an object to remote
partitions for fault tolerance.
object server
An Object Storage component that is responsible for managing
objects.
Object Storage service
The OpenStack core project that provides eventually consistent
and redundant storage and retrieval of fixed digital content. The
project name of OpenStack Object Storage is swift.
Object Storage API
API used to access OpenStack Object Storage.
Object Storage Device (OSD)
The Ceph storage daemon.
object versioning
Allows a user to set a flag on an Object Storage container so
that all objects within the container are versioned.
Ocata
The code name for the fifteenth release of OpenStack. The
design summit will take place in Barcelona, Spain. Ocata is
a beach north of Barcelona.
Oldie
Term for an Object Storage process that runs for a long time.
Can indicate a hung process.
Open Cloud Computing Interface (OCCI)
A standardized interface for managing compute, data, and network
resources, currently unsupported in OpenStack.
Open Virtualization Format (OVF)
Standard for packaging VM images. Supported in OpenStack.
Open vSwitch
Open vSwitch is a production quality, multilayer virtual
switch licensed under the open source Apache 2.0 license. It
is designed to enable massive network automation through
programmatic extension, while still supporting standard
management interfaces and protocols (for example NetFlow,
sFlow, SPAN, RSPAN, CLI, LACP, 802.1ag).
Open vSwitch (OVS) agent
Provides an interface to the underlying Open vSwitch service for
the Networking plug-in.
Open vSwitch neutron plug-in
Provides support for Open vSwitch in Networking.
OpenLDAP
An open source LDAP server. Supported by both Compute and
Identity.
OpenStack
OpenStack is a cloud operating system that controls large pools
of compute, storage, and networking resources throughout a data
center, all managed through a dashboard that gives administrators
control while empowering their users to provision resources through a
web interface. OpenStack is an open source project licensed under the
Apache License 2.0.
OpenStack code name
Each OpenStack release has a code name. Code names ascend in
alphabetical order: Austin, Bexar, Cactus, Diablo, Essex,
Folsom, Grizzly, Havana, Icehouse, Juno, Kilo, Liberty,
and Mitaka.
Code names are cities or counties near where the
corresponding OpenStack design summit took place. An
exception, called the Waldon exception, is granted to
elements of the state flag that sound especially cool. Code
names are chosen by popular vote.
openSUSE
A Linux distribution that is compatible with OpenStack.
operator
The person responsible for planning and maintaining an OpenStack
installation.
optional service
An official OpenStack service defined as optional by
DefCore Committee. Currently, consists of
Dashboard (horizon), Telemetry service (Telemetry),
Orchestration service (heat), Database service (trove),
Bare Metal service (ironic), and so on.
Orchestration service
An integrated project that orchestrates multiple cloud
applications for OpenStack. The project name of Orchestration is
heat.
orphan
In the context of Object Storage, this is a process that is not
terminated after an upgrade, restart, or reload of the service.
Oslo
OpenStack project that produces a set of Python libraries
containing code shared by OpenStack projects.
parent cell
If a requested resource, such as CPU time, disk storage, or
memory, is not available in the parent cell, the request is forwarded
to associated child cells.
partition
A unit of storage within Object Storage used to store objects.
It exists on top of devices and is replicated for fault
tolerance.
partition index
Contains the locations of all Object Storage partitions within
the ring.
partition shift value
Used by Object Storage to determine which partition data should
reside on.
path MTU discovery (PMTUD)
Mechanism in IP networks to detect end-to-end MTU and adjust
packet size accordingly.
pause
A VM state where no changes occur (no changes in memory, network
communications stop, etc); the VM is frozen but not shut down.
PCI passthrough
Gives guest VMs exclusive access to a PCI device. Currently
supported in OpenStack Havana and later releases.
persistent message
A message that is stored both in memory and on disk. The message
is not lost after a failure or restart.
persistent volume
Changes to these types of disk volumes are saved.
personality file
A file used to customize a Compute instance. It can be used to
inject SSH keys or a specific network configuration.
Platform-as-a-Service (PaaS)
Provides to the consumer the ability to deploy applications
through a programming language or tools supported by the cloud
platform provider. An example of Platform-as-a-Service is an
Eclipse/Java programming platform provided with no downloads
required.
plug-in
Software component providing the actual implementation for
Networking APIs, or for Compute APIs, depending on the context.
policy service
Component of Identity that provides a rule-management
interface and a rule-based authorization engine.
pool
A logical set of devices, such as web servers, that you
group together to receive and process traffic. The load
balancing function chooses which member of the pool handles
the new requests or connections received on the VIP
address. Each VIP has one pool.
pool member
An application that runs on the back-end server in a
load-balancing system.
port
A virtual network port within Networking; VIFs / vNICs are
connected to a port.
port UUID
Unique ID for a Networking port.
preseed
A tool to automate system configuration and installation on
Debian-based Linux distributions.
private image
An Image service VM image that is only available to specified
tenants.
private IP address
An IP address used for management and administration, not
available to the public Internet.
private network
The Network Controller provides virtual networks to enable
compute servers to interact with each other and with the public
network. All machines must have a public and private network
interface. A private network interface can be a flat or VLAN network
interface. A flat network interface is controlled by the
flat_interface with flat managers. A VLAN network interface is
controlled by the ``vlan_interface`` option with VLAN
managers.
project
Projects represent the base unit of “ownership” in OpenStack,
in that all resources in OpenStack should be owned by a specific project.
In OpenStack Identity, a project must be owned by a specific domain.
project ID
User-defined alphanumeric string in Compute; the name of a
project.
project VPN
Alternative term for a cloudpipe.
promiscuous mode
Causes the network interface to pass all traffic it
receives to the host rather than passing only the frames
addressed to it.
protected property
Generally, extra properties on an Image service image to
which only cloud administrators have access. Limits which user
roles can perform CRUD operations on that property. The cloud
administrator can configure any image property as
protected.
provider
An administrator who has access to all hosts and
instances.
proxy node
A node that provides the Object Storage proxy service.
proxy server
Users of Object Storage interact with the service through the
proxy server, which in turn looks up the location of the requested
data within the ring and returns the results to the user.
public API
An API endpoint used for both service-to-service communication
and end-user interactions.
public image
An Image service VM image that is available to all
tenants.
public IP address
An IP address that is accessible to end-users.
public key authentication
Authentication method that uses keys rather than
passwords.
public network
The Network Controller provides virtual networks to enable
compute servers to interact with each other and with the public
network. All machines must have a public and private network
interface. The public network interface is controlled by the
``public_interface`` option.
Puppet
An operating system configuration-management tool supported by
OpenStack.
Python
Programming language used extensively in OpenStack.
QEMU Copy On Write 2 (QCOW2)
One of the VM image disk formats supported by Image
service.
Qpid
Message queue software supported by OpenStack; an alternative to
RabbitMQ.
quarantine
If Object Storage finds objects, containers, or accounts that
are corrupt, they are placed in this state, are not replicated, cannot
be read by clients, and a correct copy is re-replicated.
Quick EMUlator (QEMU)
QEMU is a generic and open source machine emulator and
virtualizer.
One of the hypervisors supported by OpenStack, generally used
for development purposes.
quota
In Compute and Block Storage, the ability to set resource limits
on a per-project basis.
RabbitMQ
The default message queue software used by OpenStack.
Rackspace Cloud Files
Released as open source by Rackspace in 2010; the basis for
Object Storage.
RADOS Block Device (RBD)
Ceph component that enables a Linux block device to be striped
over multiple distributed data stores.
radvd
The router advertisement daemon, used by the Compute VLAN
manager and FlatDHCP manager to provide routing services for VM
instances.
rally
OpenStack project that provides the Benchmark service.
RAM filter
The Compute setting that enables or disables RAM
overcommitment.
RAM overcommit
The ability to start new VM instances based on the actual memory
usage of a host, as opposed to basing the decision on the amount of
RAM each running instance thinks it has available. Also known as
memory overcommit.
rate limit
Configurable option within Object Storage to limit database
writes on a per-account and/or per-container basis.
raw
One of the VM image disk formats supported by Image service; an
unstructured disk image.
rebalance
The process of distributing Object Storage partitions across all
drives in the ring; used during initial ring creation and after ring
reconfiguration.
reboot
Either a soft or hard reboot of a server. With a soft reboot,
the operating system is signaled to restart, which enables a graceful
shutdown of all processes. A hard reboot is the equivalent of power
cycling the server. The virtualization platform should ensure that the
reboot action has completed successfully, even in cases in which the
underlying domain/VM is paused or halted/stopped.
rebuild
Removes all data on the server and replaces it with the
specified image. Server ID and IP addresses remain the same.
Recon
An Object Storage component that collects meters.
record
Belongs to a particular domain and is used to specify
information about the domain.
There are several types of DNS records. Each record type contains
particular information used to describe the purpose of that record.
Examples include mail exchange (MX) records, which specify the mail
server for a particular domain; and name server (NS) records, which
specify the authoritative name servers for a domain.
record ID
A number within a database that is incremented each time a
change is made. Used by Object Storage when replicating.
Red Hat Enterprise Linux (RHEL)
A Linux distribution that is compatible with OpenStack.
reference architecture
A recommended architecture for an OpenStack cloud.
region
A discrete OpenStack environment with dedicated API endpoints
that typically shares only the Identity (keystone) with other
regions.
registry
Alternative term for the Image service registry.
registry server
An Image service that provides VM image metadata information to
clients.
Reliable, Autonomic Distributed Object Store
(RADOS)
A collection of components that provides object storage within
Ceph. Similar to OpenStack Object Storage.
Remote Procedure Call (RPC)
The method used by the Compute RabbitMQ for intra-service
communications.
replica
Provides data redundancy and fault tolerance by creating copies
of Object Storage objects, accounts, and containers so that they are
not lost when the underlying storage fails.
replica count
The number of replicas of the data in an Object Storage
ring.
replication
The process of copying data to a separate physical device for
fault tolerance and performance.
replicator
The Object Storage back-end process that creates and manages
object replicas.
request ID
Unique ID assigned to each request sent to Compute.
rescue image
A special type of VM image that is booted when an instance is
placed into rescue mode. Allows an administrator to mount the file
systems for an instance to correct the problem.
resize
Converts an existing server to a different flavor, which scales
the server up or down. The original server is saved to enable rollback
if a problem occurs. All resizes must be tested and explicitly
confirmed, at which time the original server is removed.
RESTful
A kind of web service API that uses REST, or Representational
State Transfer. REST is the style of architecture for hypermedia
systems that is used for the World Wide Web.
ring
An entity that maps Object Storage data to partitions. A
separate ring exists for each service, such as account, object, and
container.
ring builder
Builds and manages rings within Object Storage, assigns
partitions to devices, and pushes the configuration to other storage
nodes.
Role Based Access Control (RBAC)
Provides a predefined list of actions that the user can perform,
such as start or stop VMs, reset passwords, and so on. Supported in
both Identity and Compute and can be configured using the
horizon dashboard.
role
A personality that a user assumes to perform a specific set of
operations. A role includes a set of rights and privileges. A user
assuming that role inherits those rights and privileges.
role ID
Alphanumeric ID assigned to each Identity service role.
rootwrap
A feature of Compute that allows the unprivileged "nova" user to
run a specified list of commands as the Linux root user.
round-robin scheduler
Type of Compute scheduler that evenly distributes instances
among available hosts.
router
A physical or virtual network device that passes network
traffic between different networks.
routing key
The Compute direct exchanges, fanout exchanges, and topic
exchanges use this key to determine how to process a message;
processing varies depending on exchange type.
RPC driver
Modular system that allows the underlying message queue software
of Compute to be changed. For example, from RabbitMQ to ZeroMQ or
Qpid.
rsync
Used by Object Storage to push object replicas.
RXTX cap
Absolute limit on the amount of network traffic a Compute VM
instance can send and receive.
RXTX quota
Soft limit on the amount of network traffic a Compute VM
instance can send and receive.
S3
Object storage service by Amazon; similar in function to Object
Storage, it can act as a back-end store for Image service VM images.
sahara
OpenStack project that provides a scalable data-processing stack
and associated management interfaces.
SAML assertion
Contains information about a user as provided by the identity
provider. It is an indication that a user has been authenticated.
scheduler manager
A Compute component that determines where VM instances should
start. Uses modular design to support a variety of scheduler
types.
scoped token
An Identity service API access token that is associated with a
specific tenant.
scrubber
Checks for and deletes unused VMs; the component of Image
service that implements delayed delete.
secret key
String of text known only by the user; used along with an access
key to make requests to the Compute API.
secure shell (SSH)
Open source tool used to access remote hosts through an
encrypted communications channel, SSH key injection is supported by
Compute.
security group
A set of network traffic filtering rules that are applied to a
Compute instance.
segmented object
An Object Storage large object that has been broken up into
pieces. The re-assembled object is called a concatenated
object.
self-service
For IaaS, ability for a regular (non-privileged) account to
manage a virtual infrastructure component such as networks without
involving an administrator.
SELinux
Linux kernel security module that provides the mechanism for
supporting access control policies.
senlin
OpenStack project that provides a Clustering service.
server
Computer that provides explicit services to the client software
running on that system, often managing a variety of computer
operations.
A server is a VM instance in the Compute system. Flavor and
image are requisite elements when creating a server.
server image
Alternative term for a VM image.
server UUID
Unique ID assigned to each guest VM instance.
service
An OpenStack service, such as Compute, Object Storage, or Image
service. Provides one or more endpoints through which users can access
resources and perform operations.
service catalog
Alternative term for the Identity service catalog.
service ID
Unique ID assigned to each service that is available in the
Identity service catalog.
service provider
A system that provides services to other system entities. In
case of federated identity, OpenStack Identity is the service
provider.
service registration
An Identity service feature that enables services, such as
Compute, to automatically register with the catalog.
service tenant
Special tenant that contains all services that are listed in the
catalog.
service token
An administrator-defined token used by Compute to communicate
securely with the Identity service.
session back end
The method of storage used by horizon to track client sessions,
such as local memory, cookies, a database, or memcached.
session persistence
A feature of the load-balancing service. It attempts to force
subsequent connections to a service to be redirected to the same node
as long as it is online.
session storage
A horizon component that stores and tracks client session
information. Implemented through the Django sessions framework.
share
A remote, mountable file system in the context of the Shared File
Systems. You can mount a share to, and access a share from, several
hosts by several users at a time.
share network
An entity in the context of the Shared File Systems that
encapsulates interaction with the Networking service. If the driver
you selected runs in the mode requiring such kind of interaction, you
need to specify the share network to create a share.
Shared File Systems API
A Shared File Systems service that provides a stable RESTful API.
The service authenticates and routes requests throughout the Shared
File Systems service. There is python-manilaclient to interact with
the API.
Shared File Systems service
An OpenStack service that provides a set of services for
management of shared file systems in a multi-tenant cloud
environment. The service is similar to how OpenStack provides
block-based storage management through the OpenStack Block Storage
service project. With the Shared File Systems service, you can create
a remote file system and mount the file system on your instances. You
can also read and write data from your instances to and from your
file system. The project name of the Shared File Systems service is
manila.
shared IP address
An IP address that can be assigned to a VM instance within the
shared IP group. Public IP addresses can be shared across multiple
servers for use in various high-availability scenarios. When an IP
address is shared to another server, the cloud network restrictions
are modified to enable each server to listen to and respond on that IP
address. You can optionally specify that the target server network
configuration be modified. Shared IP addresses can be used with many
standard heartbeat facilities, such as keepalive, that monitor for
failure and manage IP failover.
shared IP group
A collection of servers that can share IPs with other members of
the group. Any server in a group can share one or more public IPs with
any other server in the group. With the exception of the first server
in a shared IP group, servers must be launched into shared IP groups.
A server may be a member of only one shared IP group.
shared storage
Block storage that is simultaneously accessible by multiple
clients, for example, NFS.
Sheepdog
Distributed block storage system for QEMU, supported by
OpenStack.
Simple Cloud Identity Management (SCIM)
Specification for managing identity in the cloud, currently
unsupported by OpenStack.
Single-root I/O Virtualization (SR-IOV)
A specification that, when implemented by a physical PCIe
device, enables it to appear as multiple separate PCIe devices. This
enables multiple virtualized guests to share direct access to the
physical device, offering improved performance over an equivalent
virtual device. Currently supported in OpenStack Havana and later
releases.
Service Level Agreement (SLA)
Contractual obligations that ensure the availability of a
service.
SmokeStack
Runs automated tests against the core OpenStack API; written in
Rails.
snapshot
A point-in-time copy of an OpenStack storage volume or image.
Use storage volume snapshots to back up volumes. Use image snapshots
to back up data, or as "gold" images for additional servers.
soft reboot
A controlled reboot where a VM instance is properly restarted
through operating system commands.
Software Development Lifecycle Automation service
OpenStack project that aims to make cloud services easier to
consume and integrate with application development process
by automating the source-to-image process, and simplifying
app-centric deployment. The project name is solum.
SolidFire Volume Driver
The Block Storage driver for the SolidFire iSCSI storage
appliance.
solum
OpenStack project that provides a Software Development
Lifecycle Automation service.
SPICE
The Simple Protocol for Independent Computing Environments
(SPICE) provides remote desktop access to guest virtual machines. It
is an alternative to VNC. SPICE is supported by OpenStack.
spread-first scheduler
The Compute VM scheduling algorithm that attempts to start a new
VM on the host with the least amount of load.
SQL-Alchemy
An open source SQL toolkit for Python, used in OpenStack.
SQLite
A lightweight SQL database, used as the default persistent
storage method in many OpenStack services.
stack
A set of OpenStack resources created and managed by the
Orchestration service according to a given template (either an
AWS CloudFormation template or a Heat Orchestration
Template (HOT)).
StackTach
Community project that captures Compute AMQP communications;
useful for debugging.
static IP address
Alternative term for a fixed IP address.
StaticWeb
WSGI middleware component of Object Storage that serves
container data as a static web page.
storage back end
The method that a service uses for persistent storage, such as
iSCSI, NFS, or local disk.
storage node
An Object Storage node that provides container services, account
services, and object services; controls the account databases,
container databases, and object storage.
storage manager
A XenAPI component that provides a pluggable interface to
support a wide variety of persistent storage back ends.
storage manager back end
A persistent storage method supported by XenAPI, such as iSCSI
or NFS.
storage services
Collective name for the Object Storage object services,
container services, and account services.
strategy
Specifies the authentication source used by Image service or
Identity. In the Database service, it refers to the extensions
implemented for a data store.
subdomain
A domain within a parent domain. Subdomains cannot be
registered. Subdomains enable you to delegate domains. Subdomains can
themselves have subdomains, so third-level, fourth-level, fifth-level,
and deeper levels of nesting are possible.
subnet
Logical subdivision of an IP network.
SUSE Linux Enterprise Server (SLES)
A Linux distribution that is compatible with OpenStack.
suspend
Alternative term for a paused VM instance.
swap
Disk-based virtual memory used by operating systems to provide
more memory than is actually available on the system.
swauth
An authentication and authorization service for Object Storage,
implemented through WSGI middleware; uses Object Storage itself as the
persistent backing store.
swift
An OpenStack core project that provides object storage
services.
swift All in One (SAIO)
Creates a full Object Storage development environment within a
single VM.
swift middleware
Collective term for Object Storage components that provide
additional functionality.
swift proxy server
Acts as the gatekeeper to Object Storage and is responsible for
authenticating the user.
swift storage node
A node that runs Object Storage account, container, and object
services.
sync point
Point in time since the last container and accounts database
sync among nodes within Object Storage.
sysadmin
One of the default roles in the Compute RBAC system. Enables a
user to add other users to a project, interact with VM images that are
associated with the project, and start and stop VM instances.
system usage
A Compute component that, along with the notification system,
collects meters and usage information. This information can be used
for billing.
Telemetry service
An integrated project that provides metering and measuring
facilities for OpenStack. The project name of Telemetry is
ceilometer.
TempAuth
An authentication facility within Object Storage that enables
Object Storage itself to perform authentication and authorization.
Frequently used in testing and development.
Tempest
Automated software test suite designed to run against the trunk
of the OpenStack core project.
TempURL
An Object Storage middleware component that enables creation of
URLs for temporary object access.
tenant
A group of users; used to isolate access to Compute resources.
An alternative term for a project.
Tenant API
An API that is accessible to tenants.
tenant endpoint
An Identity service API endpoint that is associated with one or
more tenants.
tenant ID
Unique ID assigned to each tenant within the Identity service.
The project IDs map to the tenant IDs.
token
An alpha-numeric string of text used to access OpenStack APIs
and resources.
token services
An Identity service component that manages and validates tokens
after a user or tenant has been authenticated.
tombstone
Used to mark Object Storage objects that have been
deleted; ensures that the object is not updated on another node after
it has been deleted.
topic publisher
A process that is created when a RPC call is executed; used to
push the message to the topic exchange.
Torpedo
Community project used to run automated tests against the
OpenStack API.
transaction ID
Unique ID assigned to each Object Storage request; used for
debugging and tracing.
transient
Alternative term for non-durable.
transient exchange
Alternative term for a non-durable exchange.
transient message
A message that is stored in memory and is lost after the server
is restarted.
transient queue
Alternative term for a non-durable queue.
TripleO
OpenStack-on-OpenStack program. The code name for the
OpenStack Deployment program.
trove
OpenStack project that provides database services to
applications.
Ubuntu
A Debian-based Linux distribution.
unscoped token
Alternative term for an Identity service default token.
updater
Collective term for a group of Object Storage components that
processes queued and failed updates for containers and objects.
user
In OpenStack Identity, entities represent individual API
consumers and are owned by a specific domain. In OpenStack Compute,
a user can be associated with roles, projects, or both.
user data
A blob of data that the user can specify when they launch
an instance. The instance can access this data through the
metadata service or config drive.
Commonly used to pass a shell script that the instance runs on boot.
User Mode Linux (UML)
An OpenStack-supported hypervisor.
VIF UUID
Unique ID assigned to each Networking VIF.
VIP
The primary load balancing configuration object.
Specifies the virtual IP address and port where client traffic
is received. Also defines other details such as the load
balancing method to be used, protocol, and so on. This entity
is sometimes known in load-balancing products as a virtual
server, vserver, or listener.
Virtual Central Processing Unit (vCPU)
Subdivides physical CPUs. Instances can then use those
divisions.
Virtual Disk Image (VDI)
One of the VM image disk formats supported by Image
service.
VXLAN
A network virtualization technology that attempts to reduce the
scalability problems associated with large cloud computing
deployments. It uses a VLAN-like encapsulation technique to
encapsulate Ethernet frames within UDP packets.
Virtual Hard Disk (VHD)
One of the VM image disk formats supported by Image
service.
virtual IP
An Internet Protocol (IP) address configured on the load
balancer for use by clients connecting to a service that is load
balanced. Incoming connections are distributed to back-end nodes based
on the configuration of the load balancer.
virtual machine (VM)
An operating system instance that runs on top of a hypervisor.
Multiple VMs can run at the same time on the same physical
host.
virtual network
An L2 network segment within Networking.
virtual networking
A generic term for virtualization of network functions
such as switching, routing, load balancing, and security using
a combination of VMs and overlays on physical network
infrastructure.
Virtual Network Computing (VNC)
Open source GUI and CLI tools used for remote console access to
VMs. Supported by Compute.
Virtual Network InterFace (VIF)
An interface that is plugged into a port in a Networking
network. Typically a virtual network interface belonging to a
VM.
virtual port
Attachment point where a virtual interface connects to a virtual
network.
virtual private network (VPN)
Provided by Compute in the form of cloudpipes, specialized
instances that are used to create VPNs on a per-project basis.
virtual server
Alternative term for a VM or guest.
virtual switch (vSwitch)
Software that runs on a host or node and provides the features
and functions of a hardware-based network switch.
virtual VLAN
Alternative term for a virtual network.
VirtualBox
An OpenStack-supported hypervisor.
VLAN manager
A Compute component that provides dnsmasq and radvd and sets up
forwarding to and from cloudpipe instances.
VLAN network
The Network Controller provides virtual networks to enable
compute servers to interact with each other and with the public
network. All machines must have a public and private network
interface. A VLAN network is a private network interface, which is
controlled by the ``vlan_interface`` option with VLAN
managers.
VM disk (VMDK)
One of the VM image disk formats supported by Image
service.
VM image
Alternative term for an image.
VM Remote Control (VMRC)
Method to access VM instance consoles using a web browser.
Supported by Compute.
VMware API
Supports interaction with VMware products in Compute.
VMware NSX Neutron plug-in
Provides support for VMware NSX in Neutron.
VNC proxy
A Compute component that provides users access to the consoles
of their VM instances through VNC or VMRC.
volume
Disk-based data storage generally represented as an iSCSI target
with a file system that supports extended attributes; can be
persistent or ephemeral.
Volume API
Alternative name for the Block Storage API.
volume controller
A Block Storage component that oversees and coordinates storage
volume actions.
volume driver
Alternative term for a volume plug-in.
volume ID
Unique ID applied to each storage volume under the Block Storage
control.
volume manager
A Block Storage component that creates, attaches, and detaches
persistent storage volumes.
volume node
A Block Storage node that runs the cinder-volume daemon.
volume plug-in
Provides support for new and specialized types of back-end
storage for the Block Storage volume manager.
volume worker
A cinder component that interacts with back-end storage to manage
the creation and deletion of volumes and the creation of compute
volumes, provided by the cinder-volume daemon.
vSphere
An OpenStack-supported hypervisor.
weighting
A Compute process that determines the suitability of the VM
instances for a job for a particular host. For example, not enough RAM
on the host, too many CPUs on the host, and so on.
weight
Used by Object Storage devices to determine which storage
devices are suitable for the job. Devices are weighted by size.
weighted cost
The sum of each cost used when deciding where to start a new VM
instance in Compute.
worker
A daemon that listens to a queue and carries out tasks in
response to messages. For example, the cinder-volume worker manages volume
creation and deletion on storage arrays.
Workflow service
OpenStack project that provides a simple YAML-based language
to write workflows, tasks and transition rules, and a
service that allows to upload them, modify, run them at
scale and in a highly available manner, manage and monitor
workflow execution state and state of individual tasks. The
code name of the project is mistral.
Xen
Xen is a hypervisor using a microkernel design, providing
services that allow multiple computer operating systems to
execute on the same computer hardware concurrently.
Xen API
The Xen administrative API, which is supported by
Compute.
Xen Cloud Platform (XCP)
An OpenStack-supported hypervisor.
Xen Storage Manager Volume Driver
A Block Storage volume plug-in that enables communication with
the Xen Storage Manager API.
XenServer
An OpenStack-supported hypervisor.
XFS
High-performance 64-bit file system created by Silicon
Graphics. Excels in parallel I/O operations and data
consistency.
zaqar
OpenStack project that provides a message service to
applications.
ZeroMQ
Message queue software supported by OpenStack. An alternative to
RabbitMQ. Also spelled 0MQ.
Zuul
Tool used in OpenStack development to ensure correctly ordered
testing of changes in parallel.
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