Theses and Dissertations

Permanent URI for this collectionhttp://ir.daiict.ac.in/handle/123456789/1

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Subject: search.filters.subject.Service-oriented architecture

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    ItemOpen Access
    Resource allocation on infrastructure as a service cloud using policies
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2010) Nathani, Amit; Divakaran, Srikrishnan
    Conventionally, a cloud refers to an Infrastructure as a service cloud. Infrastructure as a service cloud providers manage a large set of computing resources. These resources can be provided to cloud users on demand in the form of virtual machines. Cloud consumers do not need to manage resources and be worried about the performance issues because they are handled by cloud providers. Resource allocation in the context of infrastructure as a service cloud means allocating virtual resources namely computing capacity, storage etc. to competing requests based on pre-defined resource allocation policies. In real world most of the Infrastructure as a service clouds rely on simple resource allocation policies like immediate and best effort. Immediate means the resources are allocated if they are available or the request is rejected and best effort means the requested resources are allocated if they are available or the request is placed in first come first serve queue. Sometimes it is not possible for a cloud provider to satisfy all the requests which come to them immediately because of lack of resources. In this case cloud providers can benefit from more complex resource allocation policies. Haizea is a resource lease manager that tries to address above issues. It uses resource leases as resource allocation abstraction and implements these leases as virtual machines. Currently, it supports four kinds of resource allocation policies: immediate, best-effort, advance reservation and deadline sensitive. The aim of thesis is to extend the current scheduling algorithm of Haizea to support deadline leases in an efficient manner. A dynamic planning based scheduling algorithm is proposed which will admit new leases and prepare the schedule whenever a new lease can be accommodated. The proposed algorithm is implemented in Haizea. Experiments are performed to demonstrate the effectiveness of it. The results show that it maximizes resource utilization and acceptance of leases compared to the existing algorithm of Haizea.
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    ItemOpen Access
    Bidirectional service composition
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2010) Khakhkhar, Sandip; Chaudhary, Sanjay
    Service is a network addressable software component to perform a specific task. A service consumes given input parameters, performs specific task based on input parameters and returns the result in terms of output parameters. A service request specifies required task in terms of input parameters that can be provided and output parameters that are required. A service discovery mechanism can be used to find services that can be executed to satisfy service request. Service and service request is match by comparing their input/output parameters. A service request may be complex enough that it can not be satisfied by an individual service. It might be possible to execute a chain of services in a particular order to satisfy service request. This chain of services is referred as composition plan and service offered by executing this composition plan is referred as composite service. The aim of service composition algorithm is to generate a composition plan and generate composite service to satisfy service request. Services involved in composition plan are selected manually while designing composite service in static composition process. This process consumes considerable amount of time and effort. It is also vulnerable to changes in input/output of services. A dynamic composition algorithm is required that can automatically select services involved in composite plan and generate a composite service on-the-fly. Main issue with dynamic composition algorithms is composition time taken by algorithm to generate a composite service. Composition time indicates duration of the time at which the service request was submitted to the algorithm till the algorithm generate a composite service that can satisfy service request. Composition time depends upon the number of services required to explore in order to find services that can take part in composite plan. Dynamic composition algorithms presented in previous work mainly follows either forward chaining approach or backward chaining approach to find a composite service. Performance of algorithms based on forward chaining approach or backward chaining approach suffers for certain cases to generate a composite service where number of services explored increases exponentially as number of iterations increases. This work proposes a dynamic composition algorithm that gives consistent performance across all the cases. Proposed algorithm approaches from two directions alternatively, one follows forward chaining approach and other follows backward chaining approach. Composition algorithm following only forward chaining approach or backward chaining approach performs all the iterations in one direction only where as proposed algorithm requires only half number of iterations in both directions. Algorithm uses two types of matching strategy to compare input/output parameters. First one is based on keyword matching and second one based on semantic matching strategy. Performance of proposed algorithm is evaluated by performing relevant experiments and results are compared with algorithms based on only forward chaining approach or backward chaining approach. Proposed algorithm explores less number of services and takes less composition time compared to algorithms based on only forward chaining approach or backward chaining approach.
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    ItemOpen Access
    Event-driven service-oriented architecture for dynamic composition of Web services
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2008) Laliwala, Zakir; Chaudhary, Sanjay
    The Business process contains a set of services to fulfill its goal. The Service is a software component to perform a specific activity of a business process. The Business processes are event-driven and change frequently during the life cycle of a process. The state of services should be managed for proper integration during the execution of a business process. Core Web services standards are stateless and do not support event and notification. In today’s dynamic environment, changes in business process requirements, terminologies, technologies and policies need to be reflected in the software systems. To provide seamless interoperable integration, automation, execution monitoring, state and notification management of a dynamic business process, scalable software architecture is required. This thesis proposes event-driven service-oriented architecture by converging the Web services, Semantic web, and grid computing; to model, compose, deploy and execute event driven dynamic business process. Web service provides loosely coupled integration of information and services for orchestration of a business process. Semantic provides interoperable integration, automated orchestration, negotiation, content based service selection and composition of a business process. Grid business process supports state, notification, service grouping, and policy. Grid provides required middleware support for the execution of a stateful and event-driven dynamic grid business process. We propose event calculus based formal approach for event-driven modeling and rules based approach for dynamic composition. As for the proof-of-concept, agro-produce marketing process is considered. Research experiments are performed using existing open standards, specifications, and tools to realize event-driven service-oriented architecture and its life cycle.