07-11-2012, 04:36 PM
SaaAS - The Mobile Agent based Service for Cloud Computing in Internet Environment
SaaAS - The Mobile Agent based Service.doc (Size: 711.5 KB / Downloads: 49)
Abstract:
Current cloud computing systems always focus on the high bandwidth local area network environment, for example, an LAN of a corporation. This paper uses mobile agent to implement the software and data service for cloud user in Internet environment, and make the cloud computing system adaptable to work in Internet environment, such as an international corporation with branches all over the world. The works in this paper includes three parts: (1) introducing mobile agent into cloud computing system and presenting the mobile agent based service for cloud computing system: Service as an Agent Service). The SaaAS uses mobile agents as the underlying facility to offer the service for user; (2) presenting a high performance code and data of service load mechanism based mobile agent for SaaAS, which can effectively reduce the heavy communication overhead in Internet; (3) presenting a novel data coherence mechanism for SaaAS: Divided-Cloud and Convergent Coherence Mechanism (DCCM). The application of mobile agent enables SaaAS to be more suitable to work in Internet environment than conventional cloud computing system.
Introduction:
Cloud computing is a paradigm that focuses on sharing data and computations over a scalable network of nodes. Examples of such nodes include end user computers, data centers, and web services. Such a scalable network of nodes is called cloud. An application based on such clouds is taken as a cloud application. A computing cloud is a massive network of nodes. Thus, scalability should be a quality feature of the computing cloud. The most important scalability is Horizontal cloud scalability, which is the ability to connect and integrate multiple clouds to work as one logical cloud. For instance, a cloud providing calculation services (calculation cloud) can access a cloud providing storage services (storage cloud) to keep intermediate results. Two calculation clouds can also integrate into a larger calculation cloud. Scalability should be transparent to users. For instance, users may store their data in the cloud without the need to know where it keeps the data or how it accesses the data. For example, every cloud has only a finite amount of physical storage entities. Therefore, a cloud c1 may seek help from another cloud c2 for shared storage entities to fulfill some demands on storage. Such sharing requirement may result in the data to migrate among multiple clouds.
Nevertheless, the cloud user should not be aware of the distributed storage of the data . For instance, when the stored data needs to be accessed, the user may directly retrieve it from the cloud c 1. Then c1 is responsible for gathering the data from both c 1 and c2, and returns the collected data to the user. The cloud provides location transparency to applications. The cloud data storage and access may need not only intra-cloud communications, but also inter-cloud communications. That is to say, the cloud data need not only be accessed in a LAN, but also migrate in WAN.
Public cloud:
Public cloud or external cloud describes cloud computing in the traditional main stream sense, whereby resources are dynamically provisioned on a fine-grained, self-service basis over the Internet, via web applications/web services, from an off-site third-party provider who bills on a fine-grained utility computing basis.
Community cloud:
A community cloud may be established where several organizations have similar requirements and seek to share infrastructure so as to realize some of the benefits of cloud computing. With the costs spread over fewer users than a public cloud (but more than a single tenant) this option is more expensive but may offer a higher level of privacy, security and/or policy compliance. Examples of community cloud include Google's "Gov Cloud".
Hybrid cloud:
See also: Cloud storage gateway
The term "hybrid cloud" has been used to mean either two separate clouds joined together (public, private, internal or external), or a combination of virtualized cloud server instances used together with real physical hardware.
• The most correct definition of the term "hybrid cloud" is probably the use of physical hardware and virtualized cloud server instances together to provide a single common service. Two clouds that have been joined together are more correctly called a "combined cloud".
• By integrating multiple cloud services users may be able to ease the transition to public cloud services while avoiding issues such as PCI compliance.
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• A hybrid storage cloud uses a combination of public and private storage clouds. Hybrid storage clouds are often useful for archiving and backup functions, allowing local data to be replicated to a public cloud.
Private cloud:
Private cloud and internal cloud have been described as neologisms, however the concepts themselves pre-date the term cloud by 40 years. Even within modern utility industries, hybrid models still exist despite the formation of reasonably well-functioning markets and the ability to combine multiple providers.
• Private clouds have attracted criticism because users "still have to buy, build, and manage them" and thus do not benefit from lower up-front capital costs and less hands-on management, essentially "[lacking] the economic model that makes cloud computing such an intriguing concept".
• Enterprise IT organizations use their own private cloud(s) for mission critical and other operational systems to protect critical infrastructures.
Existing System:
• Existing system implemented in LAN.
• In Existing system can use Remote Procedure Call (RPC) or Remote Method Invocation (RMI) as the underlying facility, to implement the service directory coherence and service migration.
• RPC and RMI can achieve good performance in LAN, but is not suitable for Internet or WAN.
Proposed System:
• The Proposed system provide a code and data of service load mechanism based mobile agent and divided-cloud and convergent coherence mechanism of SaaAS, which can effectively reduce the heavy communication overhead in Internet.
• These features above enable SaaAS to have good flexibility, adaptability and usability and to be more suitable to work in Internet.
TYPES OF TESTS:
Unit testing:
• Unit testing involves the design of test cases that validate that the internal program logic is functioning properly, and that program inputs produce valid outputs. All decision branches and internal code flow should be validated. It is the testing of individual software units of the application .It is done after the completion of an individual unit before integration.
• This is a structural testing, that relies on knowledge of its construction and is invasive. Unit tests perform basic tests at component level and test a specific business process, application, and/or system configuration. Unit tests ensure that each unique path of a business process performs accurately to the documented specifications and contains clearly defined inputs and expected results.
Integration testing
• Integration tests are designed to test integrated software components to determine if they actually run as one program.
• Testing is event driven and is more concerned with the basic outcome of screens or fields. Integration tests demonstrate that although the components were individually satisfaction, as shown by successfully unit testing, the combination of components is correct and consistent.
• Integration testing is specifically aimed at exposing the problems that arise from the combination of components.
Conclusion:
The cloud computing system can not only work in Intranet but also work in Internet. For the unstable bandwidth and long transfer delay of Internet, the mobile agent is a better underlying facility to implement the software and data migration in wide area cloud computing system. The Mobile Agent based Service for Cloud Computing in Internet Environment (SaaAS) is presented. The code and data of service load mechanism based mobile agent and divided cloud and convergent coherence mechanism of SaaAS are also proved. In conclusion, the application of mobile agent enables SaaAS to have good flexibility, adaptability and usability and to be more suitable to work in Internet than conventional cloud computing system.
By using the agent rather than RPC/RMI as the underlying facility to implement the software and data migration, SaaAS is more suitable to the cloud computing system which works in Internet. In conclusion, the application of mobile agent enables SaaAS to have good flexibility, adaptability and usability and to be more suitable to work in Internet than conventional cloud computing system.