Viewpoint On Cloud Computing - Collabera

Position Paper
Viewpoint on Cloud Computing
Chander Damodaran
Collabera Labs

Overview
Cloud computing - is this just a hyped up terminology or is this really the next big wave in IT
towards a service based business model. What is cloud computing? What are the benefits, risks
and challenges of cloud computing? Who are some of the key players in the cloud computing
space? - These are some of the questions that architects and enterprises in general have today.
This document tries to address some of these key areas.
Cloud Computing: Background
Cloud Computing, Cloud Services, Grid Computing, Utility Computing, *aaS – Everything as a
Service, these are few of the terminologies used interchangeably to define cloud computing.
Cloud computing is definitely a new terminology; however the underlying concepts like Grid
computing, virtualization, timesharing that enabled cloud computing has been around for a long
time.
What is Cloud Computing?
Wikipedia states – “Cloud computing is a broad term that refers to dynamic provisioning of
common business applications and/or scalable and virtualized resources as a service over the
internet.” This includes,
• Infrastructure/Hardware as a Service (IaaS/HaaS)
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• Platform/Framework as a Service (PaaS)
• Application/Software as a Service (SaaS)
Brief introduction to Service layers
Though cloud computing is a generic term, a clear demarcation of the type of service used, helps
better deployment control to flexible/cost effective solution offerings.
• Infrastructure as a Service: In traditional hosting services each customer is provided
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with dedicated hardware. However, infrastructure cloud providers have a huge pool of
shared resources that is dynamically provisioned to accommodate fluctuating demand
from different enterprises. As a result, enterprises have far greater elasticity, economies
of scale and cost advantage compared to traditional data centres. Following are the
classification for infrastructure offerings,
o Private Cloud: flexible computing resources built and provisioned internally for
each enterprise users individually. Though this is still new and catching up with
enterprises, there are good number of providers like Appistry, VMWare that
enables building private clouds
o Public Cloud: dynamic and metered provisioning of computing resources on the
internet with a service dashboard to add/modify/remove resources or view
resource usage and performance

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o Hybrid Cloud: enterprises that use a combination of the above two clouds
generally fall in the classification of hybrid clouds.
Key characteristics that qualify as IaaS offerings includes,
o Automated Provisioning
o Self-service portal
o Ability to monitor resources and application performance
Key vendors in this space include Microsoft, Amazon, VMWare, GoGrid, Flexiscale and
Terremark among others
• Platform as a Service: This is the next level of abstraction where vendors typically
abstract the infrastructure and provide frameworks, runtime libraries, tools and IDE to
develop/test cloud apps locally and deploy/host these apps in the cloud. Key
characteristics that qualify as PaaS offerings includes,
o Flexible services platform that provides a framework and a consistent
programming model to develop
o Internet standards based and interoperable with existing on premise apps/other
cloud services
o Allows natural extension of existing investments
Key vendors in this space include Microsoft Azure, Amazon, Google App Engine and
Force among others.
• Software as a Service: Also termed Application as a service, includes ready to use
applications across CRM, HRM, Financial Management domains and productivity tools
like Office and Collaboration (email, messaging, blogs, wikis). Generally licensed on a
per-user basis. Key characteristics that qualify as SaaS offerings includes,
o Anywhere access and management of software on a pay per user basis
o Supports single instance multi-tenant architecture for horizontal scalability
o Can integrate/work with existing software investments
Key vendors in this space include Microsoft, Zoho, Google Apps, Salesforce CRM, IBM
LotusLive among others.

Traditional vs. Cloud based approach: A typical business case scenario
Prior to cloud computing, business analysts/architects would capture functional/non-functional
requirements and accordingly come up with application and deployment architecture that would
support these requirements. Over the years, architects have been able to abstract and extract
patterns for these commonly needed requirements.
Let’s imagine an application that accepts user queries related to income computation and
facilitates online filing of Tax returns. For completeness sake, if we were to take functional/non-
functional scenarios, we wouldn’t see a major variation in design/architecture of the functional
pieces between traditional and the cloud based approach, however it’s the non-functional
requirements where one sees the most variation.
Let’s take couple of NFRs and do a quick comparison of the solution options,
advantage/disadvantage for each of these requirements between the traditional and the cloud
based approach:
Benefits, Risks & Challenges
Business Benefits
• Zero capital expenditure, minimal operational expenditure
• Just in-time infrastructure availability
• Dynamic scaling of resources leading to efficient resource utilization
• Pay as you go utility style billing
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Risks & Challenges
• Data security: top most concern in a public cloud, do cloud providers offer end to end
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encryption, security and privacy protection
• Data Control, Compliance & Integration: Key governmental regulations require certain
data to be present within geographic boundaries and data within a single enterprise could
be located in different data sources posing integration issues
• Data Recovery: Ability to recover customer data in case of a disaster/emergency at the
cloud data centres
• Service Quality: Enterprises expect certain service levels and almost all cloud providers
do not support all the SLAs currently
Key Vendors Comparison
As with any new trend, vendors both big and small are lining up with cloud-based/cloud-aware
service offerings, the below chart tries to compare key vendors across each of the different cloud
layers against key attributes. The players in this field and the vendor maturity are changing so
rapidly that the following information is not an exhaustive list of all vendors and is current as of
August, 2009.
The comparison matrices are based on the following legend,

• IaaS – key vendor comparison matrix
• PaaS – key vendor comparison matrix
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• SaaS – key vendor comparison matrix
Cost Comparison
Finally, an approximate cost comparison matrix of hosting a similar application across the key
cloud vendors,
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Conclusion
Every passing day, new vendors arrive at the scene with cloud service offerings. Eucalyptus has
started maturing as an open standard in cloud computing. Jericho forum, part of Open Group
managed consortia has laid out the design commandments and COA framework for building
secure open cloud computing models.
In the current market scenario, which is based primarily on cost economics coupled with demands
for scalable, flexible and efficient systems that can support varied workloads, cloud computing is a
prime candidate that slots well and can achieve all these and more, however given the inherent
risks and challenges, enterprises have currently started experimenting with the cloud. Some of the
major cloud vendors like Microsoft offer a consistent and a programmable interface to mix and
match on-premise applications with cloud based/cloud aware offerings, accelerating the pace of
cloud adoption by enterprises.
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