The document discusses different cloud computing models including Platform as a Service (PaaS), Software as a Service (SaaS), and Infrastructure as a Service (IaaS). It uses an online shop application example to illustrate how these different layers are built up. PaaS refers to the IT environment needed to deliver applications, such as load balancers, web servers, application servers, and databases, but does not include the hardware, virtualization or operating system. IaaS provides the infrastructure including the hardware, virtualization and operating system. SaaS refers to applications delivered as a multi-tenant service that many companies can sign up for and use.

1. Basic Cloud Computing
Platform as a Service (PaaS) &
Software as a Service (SaaS)
1:1
Chris Sparshott
chris_sparshott@nz1.ibm.com
nz.linkedin.com/in/chrissparshott/

2. Remember this?
Many types of software environments
Hardware
Virtualisation
Operating
System
Application

3. “Platform as a Service” or PaaS
focuses on the IT environment needed to deliver
applications. This does not include the hardware,
virtualisation or operating system.
Lets start with the Application to explain how it fits
together
Application
Hardware
Virtualisation
Operating System

4. The components of an Application
• An application
provides a function
that helps the user in
some way. This may
be a spread sheet, an
accounting package,
or an online shop.
Application On-line Shop

5. The components of an Application
• The on-line shop
needs some “IT”
on which to
“run”.
• Meaning you
need a software
runtime, an
operating
system,
hardware and
supporting
components
Application On-line Shop
On-line Shop
IT Environment
- Runtime
- Operating System
- Hardware
- Supporting
components

6. Split out the Operating System and the Hardware
Virtualisation
Hardware
Operating System
Virtualisation
Hardware
Operating System
Virtualisation
Hardware
Operating System
Application On-line Shop
On-line Shop
IT Environment
- Runtime
• The operating system and
the hardware can be split
out from the application.
We will keep the runtime
and the supporting
components with the
application for the
moment
• The operating system,
virtualisation and Hardware
is called Infrastructure.
Where we sell infrastructure
in the cloud it is call
“Infrastructure as a Service”
– IaaS. This would be the
IBM Softlayer component

7. Runtime
On-line Shop
IT Environment
- Runtime
- Supporting
components
• A runtime allows the application to
“run” or execute. This means that
the application can deliver value to
the user in the way it was designed.
e.g. with an online shop, when you
select a product to buy it adds the
product to your “basket”
• The application contains the
instructions or code to interact with
the runtime ,and the hardware to
get the product to be placed in the
“basket”.
• An example of a runtime is
WebSphere Application Server

8. Supporting Components
On-line Shop
IT Environment
- Runtime
- Supporting
components
Runtime Supporting
Components
Supporting
Components
Supporting
Components
Supporting
Components
Application
Code

9. Step 1 - Users
On-line Shop
IT Environment
- Runtime
- Supporting
components
Runtime
Application
Code
Users accessing the on-line
shop via their browser

10. Step 2 – Load
Balancers
On-line Shop
IT Environment
- Runtime
- Supporting
components
Users accessing the on-line
shop via their browser
When 10,000 users at their
laptops click on a link to look
at books for sale by the
author Eleanor Catton,
somewhere a piece of
software and hardware is
working together to send the
users laptop the web page
with this information on it.
The load balancers help
spread these requests evenly
across the IT environment so
that the “system” works in an
efficient manner

11. Step 3 – Web
Servers
On-line Shop
IT Environment
- Runtime
- Supporting
components
Users accessing the on-line
shop via their browser
When you put the URL in
your browser it eventually
meets a web server. The
webserver will return to
your browser the web
page that you requested
via the URL with all the
colours and fonts etc. If
you selected a link on the
web page for books under
$5 the web server would
need to ask the
“application code” to
provide this information.

12. Step 4 – Application and
Database Servers
On-line Shop
IT Environment
- Runtime
- Supporting
components
Application
Code
Users accessing the on-line
shop via their browser
The application server has been
asked to provide a list of all the
books that are under $5 by the
web server. The application code
running on the application server
will in turn send a request to the
database servers to search of this
list of books under $5.
The database servers will return
the search result back to the
application server code which may
modify or change the result in
some way by adding images etc .
The application server will then
pass this information back to the
web servers and then back to your
laptop via the internet.

13. A quick note on Application Code
On-line Shop
IT Environment
- Runtime
- Supporting
components
Application
Code
The Application code which runs on the application
servers delivers the unique features and functions
of the online shop.
When you are on an online shop and you think that
the way that the information is presented to you
and the way you are able to order and pay for the
goods is great; the ability of the online shop to do
this is a function of the unique application code.

14. Step 4 - Storage
On-line Shop
IT Environment
- Runtime
- Supporting
components
Everytime a user of the
online shop clicks on a
link, this information is
recorded somewhere for
analysis.
This information is held
in storage or a hard disk.
iSCSI is just a type of
storage.
The information would
be analysed by an
analytics box – this is a
topic for another
presentation.
Application Code

15. Building up the layers of an application, runtime,
operating system, virtualisation and hardware
Virtualisation
Hardware
Operating System
Virtualisation
Hardware
Operating System
Virtualisation
Hardware
Operating System
Application On-line Shop
On-line Shop
IT Environment
- Runtime
• The Application code which runs
on the application servers
delivers the unique features and
functions of the online shop.
• The IT environment includes load
balancers, web servers,
application servers, database
servers and storage.
These components of the IT
environment when sold via the
cloud can be called “Platform as
a Service” or PaaS
• The operating system,
(Virtualisation) and
Hardware is called
Infrastructure.
• Where we sell infrastructure
in the cloud it is call
“Infrastructure as a Service”
– IaaS.
This would be the IBM
Softlayer component
Application Code

16. Defining a system as IaaS and PaaS
Application
IT Environment
Application
IT Environment
On-line Shop
Application
PaaS
Virtualisation
Hardware
Operating System
IaaS
Virtualisation
Hardware
Operating System
Virtualisation
Hardware
Operating System
Application Code
Application Code

17. Software as a Service - SaaS
• If we imagine that instead of an
online shop e.g. Amazon.com we
are selling a service that many
thousand of companies can sign-
up to and use to build their own
online shop e.g. shopify
This sort of “multi-tenanted”
application is still an application,
but it is also referred to as
Software as a Service or SaaS
On-line Shop
On-line Shop
solution for
anyone to sign-
up to and use.

18. Adding SaaS to the mix
Application
IT Environment
Application
IT Environment
On-line Shop
solution for
anyone to sign-
up to and use.
SaaS
PaaS
Virtualisation
Hardware
Operating System
IaaS
Virtualisation
Hardware
Operating System
Virtualisation
Hardware
Operating System
Application Code

19. Thank you – watch out for a quick
overview of Bluemix, IBM’s Paas
environment
nz.linkedin.com/in/chrissparshott/

20. 1:1
• This is the name I give to a meeting I have
with myself to look at career, life, and how to
work better in my current role.
• To be creative and provide value to a wider
group