Cloud Computing Based Solutions for Letting Agency - Case Study Example

Introduction The aim of this document is to propose a distributed and cloud based solution to a company d ‘Letting Agency’ that sells purchases property. The Agency stores the property information and allows its employees to store and access the property information from its own internal computer network. However, the Agency decides to allow the employees to access the property information even from their own computer network and the employees can add data and access the system from the public network. The document discusses a solution based on the distributed and cloud computing to meet the requirements of the Agency, keeping in view the main issues includes: the security, cost, scalability, and extensibility. The document focuses on the system architecture components include, but are not limited to the operating system, client interfaces and data storage required to successfully implement the requisite system for the Letting Agency. After thorough analysis and keeping in view the Agency’s situation and considering the advantages and disadvantages of both solutions i-e SOAP based web services and RESTful web services, the recommended design solution is based on SOAP. Finally, the document presents key features of the proposed system design keeping in view the main issues of the Letting Agency and the breakdown of the system component (Coulouris, Dollimore, Kingberg and Blair, 2012). Problem Statement As the ‘Letting Agency’ deals with the trading of the property containing confidential information, therefore, the Agency has allowed accessing the system from the internal network only. This causes a problem that even the employees cannot access the system from any public network. The Agency is facing many problems due to the inconveniences for storing and accessing information from the premises of the customers or public network. In order to solve the problem, the Agency decided to implement web services solution based on the distributed and cloud computing. Currently, there are two (2) main solutions based on the distributed and cloud computing includes: the Simple Object Access Protocol (SOAP) based web services and Representational State Transfer (REST) web services. Each of the web services solutions has its own pros and cons, constraints and limitations. One of the main deliberations required to be considered while designing the solution is the issues pertaining to the agency’s scenario. The issues of the Letting Agency regarding the development of the system include, but are not limited to the scalability of the system, development and operational cost of the system, the security of the system, extensibility of the system and system’s neutrality. Introduction to the Solutions In the World of computers, networking and internet, the utilization of resources (hardware, applications and data) from diverse locations over the internet is becoming significant and the concept or technology is known to be as ‘Cloud Computing’. The data and applications are deployed at the remote server so that these can be accessed and shared remotely over the computer networking using internet through implementation of the cloud computing technology. Usually, the cloud computing environment is known as a grid of computers that are useful for serves like a service oriented structural design (Mackenzie, 2011). The web based applications are integrated using Extensible Markup Language (XML), Simple Object Access Protocol (SOAP), Web Services Description Language (WSDL) and Universal Description, Discovery and Integration (UDDI) over the internet to provide web services. There are two (2) main parts of the SOAP envelop include: the SOAP header and SOAP body, as shown in the above given diagram. In order to provide the web services, XML is utilized to tag / attach the data, the data is transferred by the utilization of the SOAP, a list of available web services is provided with the help of UDDI and the available web services are described by utilizing the WSDL. Actually, the SOAP is utilized to exchange the information based on the XML information set for the message format and Hypertext Transfer Protocol (HTTP) or Simple Mail Transfer Protocol (SMTP) in the implementation of the web services (Muehlen, Nickerson and Swenson, 2004). The Real Estate system for adding / storing the property data into the system for the Letting Agency can easily be developed using SOAP web based services. The following diagram shows the SOAP web services flow: However, on the other hand, Representational State Transfer based (RESTful) web services is collection of connectors and data elements i-e Uniform Resource Identifiers (URI) utilized for interaction. The RESTful web services are not based on the distributed system, unlike to the SOAP web based services, however, RESTful web based services can be used as an alternate to the SOAP web based services. Moreover, the RESTful web services rely on the unique URIs instead of utilization of UDDI, WSDL and SOAP for transferring of message and negotiation. Keeping in view the issues and the scenario of the Letting Agency, the solution can be implemented using RESTful web services; however, the solution would not be appropriate as compared to the SOAP solution. The upcoming sections of the document explain how the SOAP solution for the Letting Agency is justified (Serme, Oliveira, Massiera and Roudiery, 2009). Key Features There are three (3) major built in characteristics of the SOAP based web services include: the Neutrality, Extensibility and Independence. The SOAP based web services are said to be neutral, as the data can be transferred by using any Transport Layer Protocol include: the Hypertext Transfer Protocol (HTTP), Simple Mail Transfer Protocol (SMTP), Transmission Control Protocol (TCP), or Java Message Service (JMC). The SOAP web services are independent of the programming tools to be used for the programming. And the SOAP web services are extensible or scalable, as the security and the web service routing are being improved to be presented in the upcoming versions of the SOAP (Suda, 2003). Keeping in view these built in characteristics of the SOAP web services; it determines that the implementation of the SOAP web services would resolve the issues of the Letting Agency. The following paragraphs specify the design issues along with their resolution with implementation of the SOAP web services. Security The SOAP does not support any security features alone, hence, SOAP is suffering with various security issues. Comparatively, the security features of the SOAP web services are somehow better than the RESTful web services, due to the additional specifications of the WS-*. The security of the SOAP web services is usually implemented at Transport Layer Security (HTTP authentication) and Secure Socket Layer (SSL). However, the additional / extra specification of the WS-* protocols in the SOAP web services make the message secure for an endpoint to endpoint delivery over diverse protocols. Moreover, the XML also provides a layer of security consisting of the set of World Wide Web Consortium (W3C) and encryption. Over and above all, cryptography or encryption is utilized to provide adequate security and privacy of keeping information secret. Based on such improvements, some of the security issues have been addressed include: accessibility, authentication, data integrity and authorization (Clabby, 2014). With the provision of security feature, the SOAP web services resolve one of the critical issues of the Letting Agency. Cost of Ownership There are two (2) types of costs for owning the SOAP web services include: implementation / development and operational / maintenance cost. The development cost of the SOAP web services includes: the procurement of requisite hardware, software, and storage devices, deployment of LAN / WAN and implementation of the security in the provision of the SOAP web services. The operational / maintenance cost consists of enhancing the deployed SOAP web services, network usage, energy consumption costs, communication costs (Samtani and Sadhwani, n.d). Above all, it is pertinent to mention here that implementation of the SOAP web services is costly; therefore, it is quite difficult for all the companies to implement Scalability One of the main issues of implementing the SOAP web services is the scalability. In order to make the SOAP web services scalable for the Letting Agency, the cost of adding the users should be made constant in terms of deploying hardware and software resources. Moreover, it is pertinent that the Letting Agency should consider the efficiency and performance of the SOAP web services in a way that adding users would not slow down the provision of services to the users. This can be resolved by replicating the frequent access data at diverse storage devices. Openness and Heterogeneity As the SOAP web services independent of the programming tools and this can be benefited to make the SOAP web services extensible for the Letting Agency. However, it is quite challenging to write diverse code in different programming languages by diverse programmers, for integrating the components to publish the interfaces. Moreover, as the SOAP web services are constructed using different operating systems, computer networks, hardware and programming languages, therefore, this issue needs to be considered by the Letting Agency. System Components The Letting Agency requires various system components required to implement the SOAP web services. Besides computer network, software and hardware (computers, servers), the storage system and client interfaces are the significant components. It is pertinent to discuss the how these components interact with each other to transmit the message / data, message processing, message storage and accessing data. Keeping in view the scenario, the main purpose of storage system is to maintain records, those which may contain confidential information about property; therefore, the information must be stored securely. There are diverse types of data storage devices include: Primary and Secondary and Tertiary Storage, Volatile and non-volatile storage, Read only and Writable storage, Random Access and Sequential Access storage, Magnetic storage and Optical storage (Microsoft Developer Network, 2014). The following diagram shows the process of the transmitting and receiving the messages, the data storage and the intermediary processing of the message. As far as the client interfaces are concerned, the user interface for the Letting Agency (client / user) should be developed keeping in view the usability features. Principally, there are three (3) general dialog strategies currently used to keep up a correspondence with a bilateral computer system and these three (3) strategies include: the menu driven, question / answer and command driven interfaces. From the three strategies the first two (menu driven and question / answer) are commonly over the World Wide Web (WWW), however, the command line interfaces are mostly used in the stand alone computer systems. As the SOAP web services for the Letting Agency have to be provided over the internet, therefore, from the two (2) WWW interfaces, the menu driven interface is a better choice for the interface to be developed for the Letting Agency. In menu driven interface, the users do not require remembering the commands for using the web applications efficiently; therefore, the users can effectively utilize the SOAP web services easily. Furthermore, the menu driven graphical user interface is suitable for even the novice computer for not generating the errors, as they do not require typing the commands (Senn, 2009). Moreover, it is pertinent to consider the guidelines for development of the user interfaces provided by the Jakob Neilson as ten (10) heuristics (Neilson, 2005). Conclusion The document presented a distributed and cloud computing based solutions for the real estate business. From the SOAP and RESTful web service solutions, the SOAP web services are recommended for the given scenario. Moreover, the document contains main issues regarding implementation of the SOAP web services. In order to resolve the solution’s design issues, various suggestions and recommendations have been provided in this document. The Letting Agency needs to consider and follow the guidelines in order to design and implement the SOAP web services for their real estate business. Moreover, the document discussed, not only the system components required for the design and implementation of the SOAP web services, but also provided certain guiding principles for the design of the SOAP web services. It is stated that the Letting Agency would successfully implement the SOAP web services by utilizing the document properly and resolve the underlying issues. Reference List Clabby, J. (2014). Web Service Gotchas. [online] Available at: [Accessed 5 April 2014] Coulouris, G., Dollimore, J., Kingberg, T., and Blair, G. 2012. Distributed Systems: Concepts and Design 5th Edition, Pearson: Addison – Wesley Mackenzie, T. 2011. Malicious SOAP Requests as Web Service. [online] Available at: [Accessed 4 April 2014] Microsoft Developer Network. 2014. Secure, Reliable, Transacted Web Services: Architecture and Composition. [online] Available at: [Accessed 6 April 2014] Muehlen, M., Nickerson, J. V., and Swenson, K. D. 2004. Developing Web Services Choreography Standards – The Case of REST vs. SOAP. Wesley J. Howe School of Technology Management, USA Neilson, J. 2005. 10 Usability Heuristics for User Interface Design. [online] Available at: [Accessed 7 April 2014] Samtani, G., and Sadhwani, D. n.d. Web Services and Application Frameworks (.Net and J2EE). Published by Tech, Chicago, USA Senn, J. A. (2009). Analysis and Design of Information Systems. Tata McGraw Hill Education, pp 449 - 490 Serme, G., Oliveira, A. S., Massiera, J., and Roudiery, Y. 2009. Enabling Message Security for RESTful Services. Eurecom, France Suda, B. 2003. SOAP Web Services. The University of EdinBurgh, United States, California Thankam Paul Thyvalikakath. 2009. Comparative Study of Heuristic Evaluation and Usability Testing Methods. [online]. Available at: [Accessed 19 June 2012] Read More