Cloud Architecture SPI Model l Cloud Computing Classification

Cloud Architecture

SPI Model l Cloud Computing Classification Model – SPI - Saa. S: (Software as a Service) - Paa. S (Platform as a Service) - Iaa. S (Infrastructure as a Service)

Cloud Computing as A Service [9 ] Copyright © 2012, Elsevier Inc. All rights reserved. 2 -

l l l Infrastructure services share the physical hardware Platform services share the application framework Software services share the entire software stack.

l l l Amazon Elastic Compute Cloud (EC 2) is a classic example of Iaa. S Google App Engine is generally considered to be a Paa. S Salesforce. com is a well known example of Saa. S.

Some Iaa. S Offerings from Public Clouds : Copyright © 2012, Elsevier Inc. All rights reserved. 2 -

Paa. S Offerings from Public Clouds Copyright © 2012, Elsevier Inc. All rights reserved. 2 -

Cloud Delivery Model l l Public Cloud Private Cloud Partner Cloud Community Cloud Hybrid or Multi-sourced Delivery

l Public cloud: It has large set of the following features: - Off-premise - Elastisity - Flexible billing - Virtualization - Service delivery - Universal access - Simplified management - Affordable resources - Multi-tenancy - Service level management

l Private Cloud: only leverages some of the aspects of cloud computing - hosted on-premise, - scales “only” into the hundreds or perhaps thousands of nodes, - connected primarily to the using organization through private network links. - since all applications and servers are shared within the corporation the notion of multi-tenancy is minimized.

Public Clouds vs. Private Clouds : Characterist ics Public clouds Private clouds Technology leverage and ownership Owned by service providers Leverage existing IT infrastructure and personnel; owned by individual organization Management of provisioned resources Creating and managing VM instances within proprietary infrastructure; promote standardization, preserves capital investment, application flexibility Client managed; achieve customization and offer higher efficiency Workload distribution methods and loading policies Handle workload without communication dependency; distribute data and VM resources; surge workload is off-loaded Handle workload dynamically, but can better balance workloads; distribute data and VM resources Security and data privacy enforcement Publicly accessible through remote interface Access is limited; provide preproduction testing and enforce data privacy and security policies Example platforms Google App Engine, Amazon AWS, Microsoft Azure IBM RC 2 Copyright © 2012, Elsevier Inc. All rights reserved. 2 -

l Partner Cloud: Large IT providers, such as HP Enterprise Services or IBM Global Services, run data center for operations for large customers - manage services in their own facilities; - or on customer premises; - or on property of a third party

l Community Cloud: it caters a group of organizations with common set of requirements or objectives. l The most prominent examples are government clouds that are open to federal and municipal agencies.

l Hybrid or Multi-sourced delivery:

Cloud Computing as A Service [9 ] Copyright © 2012, Elsevier Inc. All rights reserved. 2 -

Cloud and Open Source l Cloud computing can leverage open source in many ways. - Self-supported Linux is by far the most popular opernating system from infrastructure servies - Cloud provider often use Xen and KVM for virtualization - Distributed cloud framwworks, such as Hadoop, are usally open source - Web-based API make the client device less relevant, which can reduce desktop license fees by adopting Linux, Google Chrome or other opensouce client. - Many Saa. S solutions leverage open-source software, such as Sugar. CRM