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After doing the necessary research, reading blogs and white papers,
should become the dot on the horizon for your organization. But how
do you reshape your current IT spaghetti into this utopian cloud world?
APPLICATION MIGRATION TO THE CLOUD
BY JAN WIERSMA
CLOUD AND DATA CENTER EVANGELIST FOR EVOSWITCH
Migrating to external cloud computing has a significant impact
on an IT organization, their role as a supplier and the way in which
applications are developed and used. During the migration an
organization becomes less of an internal IT environment and
increases the utilization of external cloud computing environments.
It is, therefore, necessary to take the presence of composite
applications in the architecture into account. In addition, the move
from the current enterprise IT environment to the different migration
paths (SaaS, PaaS, IaaS) has its own characteristics.
One of the best ways to approach cloud migration is to view
the current IT environment from the perspective of applications
or services. At the moment not all applications are suitable for
migrating to an external cloud environment. Good candidates are
applications that are not mission-critical, are hardly integrated at all
with other important applications and those which are of no strategic
(competitive) value to the organization.
In order to reduce security risks, the application should not contain
any sensitive information. This might sound a bit limiting, but as
external cloud environments mature, more applications will be able
to migrate to these environments.
An application on a cloud platform is quite different from an
application in the traditional IT environment. In his recent farewell
blog, Roy Ozzie (formerly of Microsoft) writes about the future
challenges of the new seamless, scalable computing models.The idea
that one can just move existing applications ‘without any fuss’ does
not work. For instance, the user interface is changed to touch screen.
Or new ways of data management are implemented, such as non-
relational data models. And what about horizontal scalability? Even
programming styles (e.g. ‘fail ready’ software) ensure that existing
code is generally not instantly suitable for true cloud computing
An application portfolio analysis is the most important thing when
starting the migration. Be careful though, this can soon get out of
hand if its purpose is not clearly described or understood.Whether an
application or service is suitable for a cloud computing environment
will have to be assessed by rationalization of the portfolio. This
encompasses two ways of looking at applications in relation to the
characteristics of a cloud application environment:
1. The suitable migration option (private or public cloud)
2. The suitable migration path (IaaS, PaaS or SaaS)
Additionally, a cost analysis should determine the impact on the TCO
and the ROI, which helps build a business case.
When conducting a rationalization of an application, the following
guidelines can be used to determine whether an application (or
service) is ready for the cloud:
•• Elasticity determines whether and how an application can land
on a cloud platform. This can be measured according to three
characteristic parameters: workload, storage and utilization. The
required data can often be retrieved from monitoring tools or log
files in the existing environment.
•• Any negative impact on governance (SLA, security, legal and
an application or service being moved to the public cloud.
•• Technical feasibility: the impact on the architecture of the
application, as well as the effect on the quality of service must be
•• The extent to which the application is future-proof in functional
By applying a ratings model to these areas, it should be possible to
identify the suitability of the application or service for migration to
a cloud. While a public cloud infrastructure can offer many benefits
in terms of scale and cost when compared to a dedicated (private)
cloud environment, certain applications will never move to the
public cloud.This will chiefly be the case with applications containing
an organization’s most prized possession: mission-critical or highly
The business case for cloud application migration is not complete
without taking the target platform (private or public cloud) into
consideration. The migration and overhead costs vary significantly
depending on which option is chosen and hence also influence the
total savings achievable. A good cost analysis helps with the choice
of whether or not to move an application and the expected TCO/ROI.
It should at least include capex, opex and overheads, which can cover
the following elements, among other things:
•• Network equipment
•• Real estate (datacenter)
•• Licensing contracts
•• Migration costs
It should be reasonably easy to determine the cost advantages
for applications and services that are offered on a dedicated
infrastructure, making them good potential candidates for migration
to a cloud infrastructure. In the case of applications offered on a
shared infrastructure, it may be necessary to make a specific workload
analysis in order to determine the potential savings.
Before determining an application migration strategy it is essential to
be aware of the objectives of the organization, as well as the various
possibilities. The challenge lies in balancing organizational priorities
together with the costs.
Enterprise organizations have two choices for cloud infrastructures
(public and private). These give way to the following migration
paths: IaaS, PaaS and SaaS. The choices are driven by matters such
as the aforementioned elasticity, business models and information
2.0/ technology 2.0 strategies. At the same time there are several
factors that limit possibilities, such as technical feasibility, security,
migration costs, etc. That’s why it’s not uncommon for large
organizations to select a hybrid cloud strategy enabling controlled
strategy for all applications is counterproductive. The migration
strategy will have to be determined for each application or service
separately and must continue to develop throughout. This can only
take place after a good evaluation of the applications in relation to
the areas outlined in this article. For instance, the challenges in the
field of hardware infrastructure and architecture that are connected
with a cloud migration must become part of the overall migration
strategy. It is important that the service or application is viewed from
the total IT stack in order to discover and identify the correlation.
Each migration path has its own characteristics, which are outlined
•• Migrating an application whereby the underlying server
infrastructure is moved to a public or private IaaS environment
offers a quick way of enjoying several of the benefits offered by
cloud computing. This type of migration is uncomplicated, since it
involves merely moving the host without any modification of the
application code. Nonetheless, it should also be evident that this
type of migration only offers a small part of the benefits of cloud
computing. Examples of the services referred to above are Amazon
EC2 or Rackspace.
•• Migrating to a true SaaS architecture and hosting the application
in an environment that can serve hundreds of customers
(multi-tenant) yields the biggest cost advantages for enterprise
organizations. It also aids application rationalization by bringing
together applications with identical functionality and offering them
as a single SaaS application on a shared infrastructure. Migrating an
application to a full SaaS environment can be off-putting, however,
since most applications are not suited to this new multi-tenant cloud
architecture. The move to an SaaS environment will therefore more
likely entail a replacement of the existing application. An example
of this is the dedicated enterprise CRM by Salesforce.com. The key
here is the utilization of a basic application code that is used for all
hundreds of customers, which allows specific add-ons to be overlaid
(plug-in, mash-up or widget).
•• PaaS is available as an intermediate model. Suppliers such as
Google App Engine and Microsoft Azure supply a complete cloud IT
stack for software development and delivery. This gives the option
to build ‘true’ cloud applications and release them in a scalable and
elastic environment. However, it also produces a raft of restrictions
at every technology layer of the application stack. These limitations
mean it is often difficult to migrate existing applications and code to
code and the fact that programmers occasionally‘forget’to program
in orderly fashion (e.g. stateless/statefull). While this does not lead
to any problems in current silo IT environments, it does present a
challenge in shared PaaS and SaaS environments. For these reasons
PaaS is mainly suited to‘green field activities’.
PLANNING AND IMPLEMENTATION
Application cloud strategies often focus on the technical
consequences of migration. But don’t forget that the introduction of
cloud technologies also has consequences for the organization. For
example, it is important to consider the change in the function and
role of administration when migrating. The effect on (existing) SLAs,
service management, maintenance contracts, charging-on methods
and skill sets must also be taken into account.
to closely examine the current application and services portfolio.
Clear landing sites must be defined, such as private and public cloud,
as well as routes such as IaaS, PaaS and SaaS. It is necessary for each
application to determine if it will be replaced by an application in
a cloud environment. By evaluating the application using several
cloud basic elements and examining the costs of the application, it is
possible to map out a route to the future with a good business case.
This takes some effort, but is necessary to ensure the success of the