An Introduction to
SaaS and Cloud Computing
Ross Cooney

The challenge
Add new services for your users quickly
and cost effectively

Expand your
Infrastructure!
Buy new servers,
increase your
software costs,
provision more
datacenter capacity!!

Look to the cloud!
Pay for the bandwidth
and server resources
that you need. When
your push is done
then turn the whole
thing off!

What is the cloud?
• IT as a service
What is
• Cloud allows access to services without user technical knowledge or
control of supporting infrastructure
Cloud Computing?
• Best described in terms of what happened to mechanical power over
100 yrs ago
• Now computers are simple devices connected to the larger cloud
• Data processing, storage and software applications that used to run
locally are now being supplied by big central computing stations. They're
becoming, in essence, computing utilities.

The hype
Cluster Computing
Cloud Computing
Grid Computing

SaaS
Software as a Service
PaaS
Platform as a Service
IaaS
Infrastructure as a Service

SaaS
Software as a Service

Software delivery model
SaaS
• Increasingly popular with
SMEs
• No hardware or software to
manage
• Service delivered through a
browser

Advantages
SaaS
• Pay per use
• Instant Scalability
• Security
• Reliability
• APIs

Examples
SaaS
• CRM
• Financial Planning
• Human Resources
• Word processing
Commercial Services:
• Salesforce.com
• emailcloud

PaaS
Platform as a Service

Platform delivery model
• Platforms are built upon
Infrastructure, which is
PaaS
expensive
• Estimating demand is not a
science!
• Platform management is not
fun!

Popular services
• Storage
PaaS • Database
• Scalability

Advantages
• Pay per use
• Instant Scalability
PaaS
• Security
• Reliability
• APIs

Examples
• Google App Engine
PaaS • Mosso
• AWS: S3

IaaS
Infrastructure as a Service

Computer infrastructure
delivery model
Access to infrastructure stack:
– Full OS access
– Firewalls
– Routers
IaaS
– Load balancing

Advantages
• Pay per use
• Instant Scalability
• Security
• Reliability
• APIs
IaaS

Examples
• Flexiscale
• AWS: EC2
IaaS

SaaS
Software as a Service
PaaS
Platform as a Service
IaaS
Infrastructure as a Service

Common Factors
SaaS
• Pay per use
• Instant Scalability
PaaS
• Security
• Reliability
• APIs
IaaS

Advantages
SaaS
• Lower cost of ownership
PaaS • Reduce infrastructure
management responsibility
• Allow for unexpected resource
loads
IaaS
• Faster application rollout

Cloud Economics
SaaS
• Multi-tenented
PaaS • Virtualisation lowers costs by
increasing utilisation
• Economies of scale afforded
by technology
IaaS
• Automated update policy

Examples of usage

• Your current CRM package is not
SaaS managing the load or you simply don’t
want to host it in-house….use a SaaS
provider such as Salesforce.com
• Your email is hosted on an exchange
server in your office and it is very
slow…outsource this using Hosted
Exchange.

• You need to host a large file (5Mb) on
your website and make it available for
35,000 users for only two months
duration. Use Cloud Front from Amazon.
PaaS • You want to start storage services on
your network for a large number of files
and you do not have the storage
capacity…use Amazon S3.

• You want to run a batch job but you don’t
have the infrastructure necessary to run it
in a timely manner. Use Amazon EC2.
• You want to host a website, but only for a
few days. Use Flexiscale.
IaaS

Network Design
• Management Node
• Various scan arrays
• Cloud burst

Administration (ARACNE)
• Hosted in the Databanx
facility in Newcastle
• Over £250,000 invested
• Redundant hardware

Our scan arrays
• Each scan array contains
9 servers
• Each array can scan over
1m emails a day at
20% utilisation

Cloudburst
• New scan array in 5 minutes
• Cost of $0.90 per hour
• Use only when your network needs a
burst of capacity.

Why Cloud Computing?
• Pay per use
• Instant Scalability
• Security
• Reliability
• APIs