Cloudware Basics - Guide to Cloud Computing for Business and Technology Managers - page 267

TABLE 13.3
Comparison of Cloud Delivery Models

Service Type IaaS PaaS SaaS

Service category VM rental; online

storage

Online operating
environment, online
database, online
message queue

Application and
software rental

Service
customization

Server template Logic resource

template

Application
template

Service
provisioning

Automation Automation Automation

Service accessing
and using

Remote console,
Web 2.0

Online development
and debugging,
integration of offline
development tools
and cloud

Web 2.0

Service monitoring Physical resource

monitoring

Logic resource
monitoring

Application
monitoring

Service level
management

Dynamic orchestration
of physical resources

Dynamic
orchestration of
logic resources

Dynamic
orchestration of
application

Service resource
optimization

Network
virtualization, server
visualization, storage
visualization

Large-scale
distributed file
system. Database,
middleware, etc.

Multitenancy

Service
measurement

Physical resource
metering

Logic resource usage
metering

Business resource
usage metering

Service integration
and combination

Load balance SOA SOA, mashup

Service security Storage encryption

and isolation, VM
isolation, VLAN;
SSL/SSH

Data isolation,
operating
environment
isolation, SSL

Data isolation,
operating
environment
isolation, SSL; Web
authentication and
authorization

13.4.3 Hybrid Clouds

Hybrid clouds are formed when more than one type of cloud infrastructure
is utilized for a particular situation. For instance, an organization may utilize
a public cloud for some aspect of its business, yet also have a private cloud
on premise for data that is sensitive. As organizations start to exploit cloud
service models, it is increasingly likely that a hybrid model is adopted as the
specific characteristics of each of the different service models are harnessed.
The key enabler here is the open standards by which data and applications
are implemented, since if portability does not exist, then vendor lock-in to a
particular cloud computing provider becomes likely. Lack of data and appli-
cation portability has been a major hindrance for the widespread uptake of