Shakti Mishra

Creating Reusable Software Component from Object-Oriented Legacy System through Reverse Engineering

Due to the constant change in technology, lack of standardization, difficulties of changes and absence of distributed architecture, the business value of legacy systems have become weaker. We cannot undermine the importance of legacy systems because some of their functions are too valuable to be discarded and too expensive to reproduce. The software industry and researchers have recently paid more attention towards the component based software development to enhance the productivity and accelerate time to market. Instead of re-implementing the business critical applications with-in time and resource constraints, the best option is Software Reengineering (SRE) with effective design and architecture which can make the system better for reusability and maintainability. The main motive behind the reengineering is integrating the legacy system with emerging technologies. To achieve these goals, we have proposed a systematic and concrete model named as Component Oriented Reverse Engineering (CORE). It aims to identify and develop reusable software components. By using the reverse engineering techniques; we can extract architectural information and services from legacy system and later on convert these services into components

An efficient asynchronous mobile web service framework

The popularity of web services within the IT industry continuous to grow. Accessing web services from a small device is very com-mon these days. There are number of challenges to access a web services on mobile device due to its limited resources and the lack of bandwidth in its communication network. In Mobile devices, Synchronous web services are not feasible. It makes the user wait while each Web service processes requests and returns results. Asynchronous Web services invocation solves this performance issue and enhances the end user experience by increasing server efficiency. The architecture of asynchronous web services is con-trollable and monitor able. In order to enhance the efficiency of a mobile web services, we have created a bridge between telephony application and web application. We integrate the telecommunica-tion facility and asynchronous invocation of web services. It ex-poses telephony services as web services, so that web application can easily access telecommunication facilities through SMS messaging.

An Efficient Schema Shared Approach for Cloud Based Multitenant Database with Authentication and Authorization Framework

Software-as-a-Service (SaaS) is a service model for delivering application as cloud services over the internet on subscription basis to multiple clients. This has forced the use of shared databases termed as multitenant databases. Multitenancy refers to a technology where a single instance of application serves requests from multiple clients. The word Tenant refers to a single organization (eg. an Institution) or person. In our proposed approach, shared database shared schema approach has been proposed that offers larger number of tenants (Educational Institutions) per database server as the single database serves the database requirements of multiple Institutions. Authentication and authorization are prime requirements when dealing with multitenancy. Kerberos authentication protocol is used on the top of multitenant database for participating educational institution in a heterogeneous environment, where a tenant can also voluntarily participate in the data centre.

A Cooperative Trust Management Framework for Load Balancing in Cluster Based Distributed Systems

Establishing trust in a distributed computing environment is one of the most challenging and important aspects of cluster computing. Achieving optimal performance in clusters forces the migration of processes to other nodes. This is where trust comes into play. A secure trusted environment is needed in order to ascertain the credibility of the participating nodes working together to achieve a goal. Though trust negotiation and establishment is challenging and provides a promising approach for any node joining or leaving a cluster dynamically, very few research proposals exist to date. This paper attempts to build a trusted distributed environment for load balancing by incorporating two more server processes - registration and node authentication module in the process migration server (PMS). The proposed approach makes an attempt to design a dynamic trust management system that detects the malevolent nodes at the run time environment.

Hybrid reliable load balancing with MOSIX as middleware and its formal verification using process algebra

For many years, load balancing in distributed computing environment has been researched to enhance and optimize the scalability of the entire system. Although numerous works have been proposed on the issues of process migration and load balancing, a comprehensive approach still misses out on various fronts. An effort has been made in the present work to cite a reliable and comprehensive load balancing approach for a trusted small scale distributed computing environment based on the priority of the processes. The proposed approach introduces a Process Migration Server (PMS) that also acts as future cluster management server ensuring that the latency time in migrated process execution is reduced along with no starvation policy for any process. We also propose an effective resource sharing mechanism where our system is able to distribute the load evenly among various nodes without much overhead. This in turn increases the reliability of the overall system. To verify our approach, we have implemented hybrid reliable load balancing algorithm where MOSIX is deployed as middleware and significant performance improvement has been observed. We have compared the performance of the proposed algorithm to the default MOSIX. Our results indicate that, hybrid reliable load balancing has lowered the network traffic by 80%-90%, increased CPU utilization by 40%-50%, with 4%-9% lesser memory and computational requirement. A relationship between the formal aspect of hybrid reliable load balancing algorithm and its architectural model JMM is established through process algebra approach.

Jingle-Mingle: A Hybrid Reliable Load Balancing Approach for a Trusted Distributed Environment

Load balancing in distributed computing environment enhances the availability and scalability of entire system. The computational paradigm has shifted dramatically from standalone computing, C/S computing, distributed computing to cluster computing paradigm. Although numerous works has been done on the issue of process migration and load balancing, a comprehensive approach still misses out on various fronts. This paper presents a reliable and comprehensive load balancing approach using Jingle-Mingle Model for a trusted small scale distributed computing environment. A Process Migration Server (PMS) that also acts as future cluster management server ensures that latency time in migrated process execution is reduced along with no starvation policy for any process. Our proposed scheme that is based on hybrid scheduling algorithm maintains history of events in order to reconfigure the systems. This paper also proposes an effective scheme to recover from single point crash or failures. Hence, the distributed computing system is able to distribute the load among various nodes evenly without any overhead. This in turn increases the reliability of overall system.

Architectural Design and Issues for Ad-Hoc Clouds

Effectively using, managing and harnessing the data is the key to the success of organizations in the time to come. We propose a cloud architecture that uses donation based resources in a network & helps multiple organizations to collaborate and yet compete with each other. The resources are utilized non intrusively. Organizations collaborate to create a Data-centre, that doesn’t harm their existence or profitability. At the same time, these organizations can compete by spreading to those locations where they carry certain edge over others. This is where an ad-hoc cloud in heterogeneous environment helps to venture into remote areas with. To achieve this, ad-hoc cloud architecture is proposed along with issues and strategies.

A demand based fault tolerant file replication model for clouds

Cloud computing systems fundamentally provide access to large amounts of data and computational resources through a variety of interfaces. These resources are provided on demand through file servers available across cloud service providers. Different file replication mechanisms are used to address the key issues such as scalability, reliability and fault tolerance. Though replication potentially improves fault tolerance, it leads to the problem of ensuring consistency of replicas and the nodes are not accessing out-of-date (or stale) file. However, fewer replicas also decrease concurrency and the level of file availability. A correct synchronization between replication mechanism and consistency not only ensures highly reliable and fault tolerant system but also improves system performance significantly. This paper presents a threshold based file replication model that replicates the file on other servers based on the number of file accesses. The simulation results indicate that proposed model reduces the number of messages exchanged for file replication by 33-55% and 25-50% as compared to request reply and request reply acknowledgement protocol, thus improving the system performance significantly.

An optimized scheduling algorithm for migrated jobs in trusted distributed systems

In present computing plethora, the cluster technology seems to gain popularity day by day. The prime reason for this popularity is high availability, increased reliability and high performance through efficient resource usage. To realize these benefits, the processing capacity of various nodes in a cluster must be allocated fairly. Often the clusters suffer from under utilization due to inappropriate choice of scheduling policy. The goal of the scheduling is to exploit the true potential of the system. Hence, finding the appropriate granularity of tasks and distributing them in such a way so that each machine is assigned equal work and thus, balancing the load across the cluster, is major issue of concern. Usually, it is seen that local processes get priority over remote processes and migrated (remote) processes begin to starve. We propose an optimized scheduling approach for migrated processes that ensures reduced latency time along with no starvation policy for any (local or remote) process. Our experimental results have been able to establish that priority and criticality based scheduling approach can increase overall system throughput by about 30–50 percent.

Simplifying Web Service Discovery & Validating Service Composition

Web services are software components developed to simplify machine-to-machine interaction over the Web. Many researches are targeted towards Web service standardization, and these efforts have significantly contributed towards improving functionality of Service Oriented Architecture (SOA). However, there are number of issues yet to be resolved. Among them, one of the major challenges is the standardization of Web service composition. When a single web service cannot satisfy the given request, composition of web services need to be incorporated. In this paper, we address Web service composition problem with the signature-based service discovery and composition approach[30]. In the proposed approach, each web service is described by WSDL. Our design eliminates the need of complicated discovery agents like UDDI and also facilitates validation of the service before actually accessing it for integration. The composition problem has been modelled as a finite state machine, which means if the all the intermediate states are rightly composed then the final composition is successful. We propose a simple yet efficient algorithm DISCOMP for the discovery and composition. This paper analyses build time and runtime issues related to signature-based approach. We support our design decision with implementation and performance results obtained on a decentralized setup.