Cloud computing has spawned a new taxonomy for IT. Ubuntu explains 50 key terms to help DevOps and IT professionals to lead their organizations through the journey to the cloud.

1. Term Definition
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2. Term Definition
It has created its own vocabulary, with new
words and phrases to describe technologies,
practices and concepts that had scarcely been
imagined five or ten years ago.
And while everyone can agree on the definition
of some of them, others are still in flux, too
new to be pinned down to a single meaning.
Some are used in different ways by different
vendors and groups, depending on their own
particular stance on cloud. It’s a bit of
a semantic minefield.
This glossary is our attempt to define
50 terms used in cloud computing today.
Most of them are vendor-independent, but
you’ll find a few Canonical-specific terms in
here too. As we’re the company behind Ubuntu,
the most popular operating system for the
cloud, some of our own terminology reflects
– and is inextricably linked with – wider cloud
computing concepts.
So you’re clear on the distinction, we’ve
highlighted Canonical terms. We’ve also
asked some of our top people to expand
on some of the words and phrases throughout
the glossary, to give you an idea of where
we stand on certain key concepts.
We hope you find this glossary useful –
and if there’s anything you’d like further
clarification or advice on, please do get in touch
on +44 (0)20 763 2471 or ubuntu.com
The Canonical Cloud Team
Cloud is changing more than
just the way we use IT infrastructure
and deliver IT services. It’s also
changing the way we talk about IT.

3. Term Definition
Anything as a
Service (XaaS)
The collective term for anything being provided as a service
through a cloud based computing model. SaaS, IaaS and PaaS
are forms of XaaS.
Automated
Provisioning
The automatic creation, configuration and deployment of new
virtual machine instances in a cloud environment. Automated
provisioning is a critical element of cloud computing as it enables
new instances to be created and activated instantly to meet
user demand.
Autoscaling The ability to add or de-provision cloud services and
infrastructure automatically, depending on usage demands.
See also: Elastic Computing
Big Data Very large volumes of structured or unstructured data that
have the potential to offer deep business or market insight
when analysed. Full description
Canonical The company behind Ubuntu, the world's most popular
distribution of the Linux operating system.
Charms Juju Charms are a set of pre-written instructions that deploys
a cloud service. Charms encapsulate the knowledge connected
with an application—dependencies, relations and platform
configuration—to enable developers to deploy new cloud
services quickly.
Closed Cloud A cloud environment built using proprietary, licensed
software components.
Cloud A model for enabling convenient, on-demand network 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
Bursting
The act of moving heavy, occasional workloads from a private
cloud into the public cloud for more cost-effective processing.
See also: Cloudstorming

4. Term Definition
“The stability of Ubuntu gives us
peace of mind that our systems and
data will be constantly available, and
that the site will stay up at all times.”
Leandro Reox, Senior Analyst and
Cloud Builder, Mercadolibre

5. Term Definition
Cloud
Orientated
Architecture
A computing environment in which individual cloud applications
are orchestrated together to perform a specific service
or automate a specific process.
Cloud
Portability
The ability to move applications and data easily from one cloud
provider to another.
Cloud
Provider
A company that provides cloud services, whether software
as a service (SaaS), platform as a service (PaaS)
or infrastructure as a service (IaaS).
Cloud
Sourcing
The act of buying cloud services (whether SaaS, PaaS or IaaS)
from an external provider.
Cloud
storming
The act of moving heavy, occasional workloads from a private
cloud into the public cloud for more cost-effective processing.
See also: Cloudbursting
Cluster A group of servers, implemented to act like a single system to
enable high availability or workload balancing.
Data as
a Service
(DaaS)
A cloud service by which data files such as text, sound and
images are provisioned and distributed to users for use in their
own applications. Delivery is normally via the public internet.
Elastic
Computing
The ability to add or de-provision cloud services and
infrastructure automatically, depending on usage demands.
See also: Autoscaling
Federating/
Federation
The act of combining data or user identities across
multiple systems.

6. Term Definition
Grid
Computing
Grid computing is where workstations on the same network have
their resources pooled in order to complete computing tasks to
address a single problem. Grid is sometimes used synonymously
with cloud computing.
Guest
Instance
In the cloud, a self-contained instance of an operating system
provisioned for the user for the duration of their session in the
cloud.
Hadoop An open-source file system that is optimised for the storage
and retrieval of very large data sets. See also: Big Data
Hybrid Cloud A cloud computing strategy that makes use of both private
and public cloud infrastructure - sometimes shifting workloads
between them as economics and demand for computing
resource dictate.
Hyperscale A description commonly applied to a data center characterised
by a high-volume, high-density deployment of commodity blade
servers. Full description
Infrastructure
as a Service
(IaaS)
A service that provides organisations with access to elastic,
on-demand computing resources in the cloud, including servers,
storage and networking, on top of which the customer may
deploy their own applications, middleware, database, virtual
machines and operating system software.
Juju A service orchestration tool from Canonical that enables the use
of charms to deploy new services quickly and easily in the cloud.
Full description
Keystone An identity service used in authentication and high-level
authorization for users of the OpenStack cloud platform.
Landscape A systems management and monitoring service from Canonical
that allows users to manage multiple Ubuntu machines easily
and reduce management and administration costs.

7. Term Definition
Metal as
a Service
(MaaS)
Developed by Canonical, a method of quickly and easily
provisioning hardware servers for the deployment of complex
services that need to scale up and down dynamically,
like Ubuntu’s OpenStack cloud infrastructure.
Multi-
Tenancy/
Multi-Tenant
Typical of many Software as a Service solutions (SaaS), a multi-
tenancy architecture sees multiple customers (tenants) sharing
a single instance of a software application, with their own data
securely partitioned from other users' data.
MySQL An open source relational database management system,
developed by Sun Microsystems and now managed by Oracle,
that is often used in web applications.
NoSQL A broad class of non-relational database management systems
designed for the storage and retrieval of very high volumes
of data that exceed the limitations of traditional relational
databases. See also: Big Data
Open Cloud A cloud infrastructure built using free, open source
software components. Full description
Proprietary Cloud software that incurs license costs and/or which has limited
interoperability with other software components due to its
closed, proprietary APIs.
Open Source Any piece of software whose source code is open and available
for anyone to use, modify, contribute to and improve upon.
Open source software is typically free of charge to license
and use.
OpenStack An open source computing platform comprised of multiple,
interoperable software components, for creating cost-effective,
high-performance private or public clouds. Full description
Platform as a
Service (PaaS)
A cloud service for developers and organisations to deploy
cloud applications using third party virtual machines, operating
systems, middleware, networking, storage and hardware.
Typically the developer creates and maintains application
code and the PaaS provider manages the layers below it.

8. Term Definition
Private Cloud A cloud computing infrastructure that an organisation builds in
its own data centre and maintains behind the corporate firewall.
Proprietary Cloud software that incurs license costs and/or which has limited
interoperability with other software components due to its
closed, proprietary APIs.
Public Cloud The public cloud allows organisations to use and deploy software
(applications, databases, storage) on systems that are hosted
and managed outside their firewalls. It differs from traditional
managed services in that the instances are virtualised and can be
created, updated and terminated using an API.
Server Image A file that contains all the information needed to create a new
instance of a server virtual machine in a cloud environment. It
reduces the time it takes to configure a new server each time
one is needed.
Service
Migration
If you are using a cloud service vendor, then service migration
is when you move your cloud from one vendor to another.
Service
Orchestration
An essential part of Cloud, service orchestration allows for the
automated provisioning of services, applications and workflows
so that resources can be scaled or provisioned in the cloud
automatically. See also: Juju, Autoscaling, Hyperscale
Single-
Tenancy
In Software as a Service (SaaS), a model by which an individual
customer (tenant) has access to a single instance of an
application and the infrastructure behind the application serves
this one tenant. See also: SaaS, Multi-Tenancy
Software as a
Service (SaaS)
A software application that is deployed on a cloud infrastructure
by a third-party cloud provider and made available to users
over a network such as a VPN or the public internet. SaaS is
typically deployed on a multitenant model, whereby multiple
users share the same application instance and underlying cloud
infrastructure. Typically, customers are billed either on a monthly
subscription or a pay-as-you-go model, based on the number
of users accessing the application, the amount of data stored,
or the amount of processor resource consumed.

9. Term Definition
Spinning Up The process of creating and activating a new virtual machine
image in a cloud environment. In cloud infrastructures that
require high elasticity due to fluctuating user volumes,
the ability to spin up new instances quickly and easily is critical.
Ubuntu The world's most popular distribution of Linux, Ubuntu is
a free, open-source operating system that scales all the way
from consumer electronics to the desktop, and into the cloud
for enterprise computing.
Ubuntu Cloud
Guest
An easy way of installing Ubuntu Server instances on any
of the leading public clouds or in a private cloud environment.
Ubuntu is the most heavily used guest OS on both
Amazon AWS and Rackspace Cloud.
Ubuntu Cloud
Infrastructure
A full OpenStack IaaS platform built into Ubuntu Server version
12.04 LTS and higher, providing all the tools you need to create
a private IAAS cloud on your own hardware.
Virtualisation A way of making better use of available hardware resources
by running multiple operating systems on one server as
"virtual machines", and managing the virtualized software layer
separately from the hardware. With its emphasis on decoupling
software from hardware, virtualization is a step on the way to
cloud computing. Virtualization cannot be thought of as true
cloud computing, however, because it does not offer elastic
scaling of resources or automated provisioning of new virtual
machine instances.
Workload A term coined by IBM to describe any application or system
that is moved into the cloud.

10. Term Definition
Wikipedia defines Big Data as datasets that
“grow so large that they become awkward
to work with,” presenting difficulties in
“capture, storage, search, sharing, analytics,
and visualisation.”
Typically, datasets grow to enormous sizes
when they are captured by always-on devices,
from aerial sensory technologies, software logs
and cameras, to microphones, wireless sensor
networks and optical network components.
While Big Data presents significant challenges,
it also offers many benefits for organisations
looking to understand trends and identify
new opportunities. But to accommodate Big
Data applications, underlying technology
infrastructure must be scalable, powerful and
hugely reliable. Applications must be designed
to scale well in distributed environments, and
deliver results fast.
That’s why Big Data applications are often
deployed in the cloud, where resources can
be added and removed quickly on demand
with a ‘pay-as-you-go’ model. For smaller
organisations, the cloud is the only financially
viable way to access the significant computing
resources required.
While many proprietary software vendors have
cloud offerings and claim to offer virtually
unlimited scalability, their commercial model
is often a barrier to entry. The standard ‘use
more, pay more’ approach doesn’t lend itself
to computing elasticity, or to cost-effective Big
Data analytics.
“Proprietary software doesn’t lend itself to
cost-effective Big Data analytics.”
Open-source technology is helping
organisations of all types and sizes convert
massive datasets into meaningful business
intelligence. Ubuntu makes this possible
with technologies for distributing NoSQL
databases, file systems and innovative Big Data
applications such as Hadoop, across tens
or even hundreds of nodes.
Today, Ubuntu is one of the leading operating
systems for supporting Big Data applications
and new Big Data development – both on
dedicated hardware and in the cloud. Our
commercial model makes Ubuntu ideal for Big
Data, as our software can be deployed on any
number of servers with no additional licensing
costs, enabling organisations to scale Big Data
activities without restrictions.
Big Data defined
By Mark Baker, Ubuntu Server
Product Manager, Canonical
Canonical White Paper –
Ubuntu: Helping Drive Business
Insight from Big Data ?

11. Term Definition
Servers used to aspire to being expensive.
Powerful. Big. We gave them names like
“Hercules” or “Atlas”. The bigger your business,
or the bigger your data problem, the bigger
the servers you bought. It was all about being
beefy – with brands designed to impress, like
POWER and Itanium.
Today, server capacity can be bought as a
commodity, based on the total cost of compute.
We can get more power by adding more nodes
to clusters, rather than buying beefier nodes.
We can increase reliability by doubling up, so
services keep running when individual nodes
fail. Much as RAID changed the storage game,
this scale-out philosophy, pioneered by Google,
is changing the server landscape.
In this hyperscale era, each individual node
is cheap and wimpy – but together, they’re
unstoppable. The horsepower now resides
in the cluster, not the node. The reliability
of the infrastructure depends on redundancy,
rather than heroic performances from
specific machines.
“The horsepower now resides in the cluster,
not the node.”
The catch, however, is in the cost
of provisioning. Hyperscale won’t work
economically if every server has to be
provisioned, configured and managed
as if it were a Hercules or an Atlas. To reap
the benefits, we need leaner provisioning
processes.
That’s why Canonical developed Metal as a
Service. MAAS makes it easy to set up the
hardware on which to deploy any service that
needs to scale up and down dynamically –
a cloud being just one example. With a simple
web interface, you can add, commission, update
and recycle servers at will.
In the hyperscale world, an operating system
like Ubuntu makes even more sense. Its
freedom from licensing restrictions, together
with the labour saving power of tools like
MAAS, make it cost-effective, finally, to deploy
and manage hundreds of nodes at a time.
Hyperscale defined
By Mark Shuttleworth,
Founder, Canonical
Webinar –
Ubuntu Cloud, with Mark Shuttleworth &
Stephen O’Grady of Redmonk

12. Term Definition
A Juju charm is a collection of instructions that
deploys, updates and scales a particular cloud
service. When defining a new workload or
service, a charm is created for it using whatever
system works best. It can be a shell script, it can
use puppet, or it can use any other framework
you like. This makes it easy to re-use existing
tools or expertise that may be present
in-house, wrapping it up in a way that will
work on the cloud.
Most services can be charmed in an hour or
two, at least for initial testing. And investments
in a charm pay off every time it is re-used.
Charms encapsulate everything a service needs
to know about itself, or tell other services
about itself, so it’s very easy to re-use them
in a different team or environment.
“Investment in a charm pays off every
time it is re-used.”
Canonical maintains a collection of public
charms that are developed in the open, under
the same transparent governance that has
made Ubuntu the leading cloud OS. Each charm
distills best practice from the leading devops
for that particular service, worldwide. Juju puts
them all at devops teams’ fingertips.
Those charms continue to improve and evolve,
so cloud deployments become smarter, more
efficient and more reliable every time they are
updated. In a recent example, work done to
reduce the cost per day of a very high-traffic
cloud-hosted website was shared immediately
with other websites using the same cloud stack.
In an enterprise setting, an improvement to the
charm for a component in many cloud stacks
brings benefit to all users.
The collection of Juju charms includes all
the common components of typical cloud
deployments – popular databases, web
application servers, load balancing systems,
computational frameworks; everything from
game servers to finite element analysis
is ready for off-the-shelf deployment in
the cloud.
Juju defined
By Mark Baker, Ubuntu Server
Product Manager, Canonical
Canonical White Paper –
Ubuntu: Helping Drive Business Insight
from Big Data

13. Term Definition
Open-source software is increasingly at the
heart of the biggest changes happening in
enterprise computing all over the world.
Open cloud is a perfect way to illustrate the
benefits open source is bringing businesses.
The business case for switching to or adopting
cloud computing – and in particular, the open
cloud – has never been stronger. Enterprises
are reducing costs and increasing flexibility
without the risk of vendor lock-in. Open clouds
let organisations move critical workloads to the
cloud with the confidence that they can move
from one vendor to another – or on to a private
cloud – as they demand. This is because open
source technology complies with established
open standards.
“The business case for switching to the open
cloud has never been stronger”
As well as delivering many business benefits,
open cloud software like Ubuntu 12.04 LTS
is also helping devops massively reduce the
complexity of cloud projects with deployment
and service orchestration tools like Juju
and MAAS. These sorts of technologies are
streamlining the deployment process, making
it quicker and simpler than ever to get
applications running in the cloud.
The combination of Ubuntu and OpenStack
has rapidly become the platform of choice
for businesses building private cloud
infrastructure.
Open Cloud defined
By Susan Wu, Cloud and Virtualization
Product Marketing Manager, Canonical
Canonical White Paper –
Creating the Open Cloud

14. Term Definition
The OpenStack Foundation is leading the cloud
industry in developing the most cutting-edge
open enterprise-class cloud platform available.
As a founding platinum member of the
OpenStack Foundation, Canonical contributes
to the project’s governance, technical
development and strategy. We’re helping
service providers and enterprises, as well as
their customers and users, benefit from the
open technologies that are making the cloud
more powerful, simple and ubiquitous.
Ubuntu has been the reference operating
system for the OpenStack project since the
beginning. That makes it the easiest and most
trusted route to an OpenStack cloud, whether
for private use or as a commercial public cloud
offering. We include it in every download of
Ubuntu Server, giving us a huge interest in its
continuing development.
OpenStack developers are building and testing
on Ubuntu every single day, which is why
Ubuntu can fairly claim to be the most tightly
integrated OS with OpenStack – and the most
stringently tested. Today, thousands of global
enterprises and service providers are deploying
their cloud infrastructures on Ubuntu and
OpenStack. Organisations like Mercadolibre,
Internap and Nectar are running mission critical
applications on their Ubuntu OpenStack clouds.
Ubuntu and OpenStack are also powering
clouds at the likes of HP, AT&T, Rackspace
and Dell.
Over recent months, other technology vendors
have recognised the lead and impact that
OpenStack is making in the market and have
announced their commitment to the project.
We should see even more of them joining the
party and coming up with OpenStack offerings
in the months to come. But in the meantime,
the best way to build your OpenStack cloud
is through the proven, rock-solid combination
of OpenStack and Ubuntu.
OpenStack defined
By Kyle MacDonald,
VP of Cloud, Canonical
Case Study –
Mercadolibre Builds 1,000-Node Private
Cloud with OpenStack and Ubuntu

15. Term Definition
We hope you’ve found this glossary useful.
To find out more about building a cloud
infrastructure with Ubuntu, visit the
following resources:
To find out more about cloud computing with
Ubuntu: www.ubuntu.com/I-cloud
To learn about Ubuntu Advantage,
the Canonical support programme for your
Ubuntu cloud deployments:
ubuntu.com
To speak directly to a member of the Canonical
team: +44 (0)20 763 2471
Thank you for reading!
The Canonical Cloud Team
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