Cloud computing and software architecture

Running head: CLOUD COMPUTING AND SOFTWARE ARCHITECTURE
Cloud Computing and Software architecture
Name of the Student
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Introduction
With the ever-increasing demand of the services provided by the Department of Spatial
Information (DSI), it becomes very hard to cop with the existing infrastructure. In order to
improve the scenario, it is important to adopt the cloud computing paradigm in order to store and
make the data available to the government agencies as well as to the public users (Guyon,
Orgerie and Morin 2018). Different sections of this report contribute to evaluation of two
possible models, and possible architecture for the selected one. Furthermore, the paper also
contributes to the discussion about Differences between monolithic and microservice
architectures and recommendations for DSI.
Evaluation of IaaS and PaaS
IaaS model
Advantages
In IaaS, the organizations are able to use the required infrastructure as a service without
like networking, storage and other services in order to run and deliver services without buying
them or maintaining those equipment’s on premise. In this cloud model organizations can pay
for their usage depending upon the capacity and space used in a given time period.
There are three different models in which the IaaS is delivered, these are public, private,
and hybrid cloud delivery model. In private cloud model the required infrastructure is set up at
the customer organizations-premise (Guyon, Orgerie and Morin 2018). On the other hand for
public cloud model the infrastructure is located at any of the cloud service providers data center,
and finally in hybrid cloud delivery model, the service is delivered as the combination of the

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above two delivery models in which the client organization selects best features of public
cloud and private cloud.
Following are the advantages of the IaaS service model,
Scalable computing resources: In case of IaaS as applications are needed to be executed
and the service have to be delivered by using the computing as a Service. In this scenario the
vCPUs (virtual central processing units) as well as virtual main memory are provided for the
Vms that ate allocated to end- users.
Storage: Back-end storage for storing data as well as required files are also provided by
the service providers.
Network and Load balancers: Through the infrastructure the Network as a Service is also
provided. In these services the networking components like the routers, switches, gateways for
connecting the Vms are utilized. Furthermore, in order to handle the application requests which
is running on the infrastructure, the load balancing capability is also provided.
Disadvantages
The main disadvantages of the IaaS are lack of security. While using the IaaS services,
the organization does not have control over the security measures thus completely depend on the
service providers.
The upgrade and maintenance of the used frameworks and applications depends solely
on the client organization.

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PaaS model
Advantages
In case of the PaaS, the advantages include reduced cost. As the organization have to
pay for what they will use provided by the cloud service provider saving costs that can be used
in improving other operations.
Provides scalability with minimum down time.
Figure 1: Advantages of PaaS
(Source: Guyon, Orgerie and Morin, 2018)
.
Disadvantages
Lack of compatibility with the lack of legacy frameworks used by the organizations.
Benefits
of PaaS
Reduced cost
Lesser
Downtime
Automated
updated and
maintainance

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Lack of security as the resources are allocated in a shared manner thus there is lack of
security mechanisms for the stored sensitive data.
Possible architecture for OSDS
PaaS architecture will be best possible option for the Department of Spatial Information.
With the adoption of the PaaS technology, the organization will be independent from the
maintenance of the on-premise infrastructure for deploying the application and providing the
services with the configuring, building the application (Guyon, Orgerie and Morin, 2018). With
the Automated updates of the applications: The PaaS service providers constantly perform the
and maintains the updates, security patching of the different frameworks in automatic manner.
Use of Cloud Edge for OSDS
The organization should consider about adopting the cloud edge solution. The solution
will help the organization in order optimize as well as enhances the quality of the services along
with the cloud-based advantages. These advantages include automatic deployment of the
services, elastic scaling of the application and database according to the demand in order to meet
top grade requirements in terms of availability and performance.
Software architecture
Differences between monolithic and microservice architectures
For a software application is said to be a monolithic application when it has single code
base with numerous modules that helps in the delivering different functionalities. The modules
of the application are divided depending upon the business/ technical features (Mazlami, Cito
and Leitner, 2017). The monolithic applications depend on a single build system for building the
entire application with only one executable file or deployable binary after the build.

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There are numerous challenges associated with the use of monolithic architecture for the
applications that will be used to deliver services to different users/stakeholders some of them are
listed below;
As the applications with the monolithic architecture have a single code base, thus it leads
to the complication in understanding the code for the new developer in the organization
(Kecskemeti, Kertesz and Marosi, 2016).
Scaling of the concerned application with the increasing functionality becomes very
challenging.
After every build the complete application is required to be deployed again which is
again time consuming and challenging.
In case of the microservices architecture, the complete application contains a collection
of autonomous and small services (Mazlami, Cito and Leitner, 2017). Each of these small
services are self-contained and are responsible for implement a single business functionality.
All the services are small in size, independent of each other and most of the times loosely
coupled.
Every service in the microservice architecture has its own separate codebase that can be
easily managed by small application development team.
As the services have small units thus, they can be deployed independently of each other.
Small team of developers can easily update existing services without the requirement of the
rebuilding and redeploying entire application/system.

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Advantages and disadvantages of different architectures
Evaluation of software architectures
In Monolithic structure, Due to the single and large code base of the application, build
time after every modification increase (Mazlami, Cito and Leitner, 2017). Furthermore, if at any
point of time it is there is a requirement of changing the technology/language along with the
frameworks in order to make the application using the hybrid technologies then it become very
difficult as every module of the application is tightly coupled as well as depend on each other.
On the other hand, if at any point of time it is there is a requirement of changing the
technology/language along with the frameworks in order to make the application using the
hybrid technologies then it becomes very difficult as every module of the application is tightly
coupled as well as depend on each other (Kecskemeti, Kertesz and Marosi, 2016).
Recommended approach
As the Online Spatial Delivery System provided different services to the government and
public sectors thus it is recommended to utilize the micro service architecture as the organization
is considering to migrate to the cloud. Through this way the organization will be able to update
any of the deployed services without shutting down the complete application and redeploying
entire application every time. In the same way updates can be rolled back or forwarded in case of
an update does not function in the desired way. Through the use of the microservice architecture
it is easy to manage bug fixes as well as feature added releases with lesser amount risk.
Conclusion
In case any of the service goes down for some reason then it would not be necessary to
take the entire application down. Whenever any kind of change in the services will be required in

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the application, then only the related service can be taken down, modified and redeployed with
the changes in lesser amount of time.

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References
Al-Debagy, O., & Martinek, P. (2018, November). A Comparative Review of Microservices and
Monolithic Architectures. In 2018 IEEE 18th International Symposium on
Computational Intelligence and Informatics (CINTI) (pp. 000149-000154). IEEE.
Djemame, K., Bosch, R., Kavanagh, R., Alvarez, P., Ejarque, J., Guitart, J., & Blasi, L. (2017).
Paas-iaas inter-layer adaptation in an energy-aware cloud environment. IEEE
Transactions on Sustainable Computing, 2(2), 127-139.
Guyon, D., Orgerie, A. C., & Morin, C. (2018, September). Energy-Efficient IaaS-PaaS Co-
design for Flexible Cloud Deployment of Scientific Applications. In 2018 30th
International Symposium on Computer Architecture and High Performance Computing
(SBAC-PAD) (pp. 69-76). IEEE.
Kecskemeti, G., Kertesz, A. & Marosi, A.C., 2016, August. Towards a Methodology to Form
Microservices from Monolithic Ones. In European Conference on Parallel
Processing (pp. 284-295). Springer, Cham.
Leitner, P., Cito, J., & Stöckli, E. (2016, December). Modelling and managing deployment costs
of microservice-based cloud applications. In Proceedings of the 9th International
Conference on Utility and Cloud Computing (pp. 165-174).
Mazlami, G., Cito, J., & Leitner, P. (2017, June). Extraction of microservices from monolithic
software architectures. In 2017 IEEE International Conference on Web Services
(ICWS) (pp. 524-531). IEEE.

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Mealha, D., Preguiça, N., Gomes, M. C., & Leitão, J. (2019, March). Data Replication on the
Cloud/Edge. In Proceedings of the 6th Workshop on Principles and Practice of
Consistency for Distributed Data (pp. 1-7).
Moudjari, R., Sahnoun, Z., & Hadjali, A. (2018). Cloud Edge Computing for Internet of Things
Elasticity Management. In ICAASE (pp. 130-133).
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