Designing Change Assimilation Process using Close-up Down Graph for Switch Based Networks

In today’s modern switch-based interconnected systems require high performance, reliability and availability. These switch based networks changes their topologies due to hot expansion of components, link or node activation and deactivation. Device failures in high-speed computer networks can also result in topological changes. Also, component failures, addition and deletion of components cause changes in the topology and routing paths supplied by the interconnection network. Therefore a network reconfiguration algorithm must be executed to reestablish the connectivity between the network nodes. Now we have two types of reconfiguration techniques and they are static reconfiguration and dynamic reconfiguration. Static reconfiguration techniques significantly reduce network service since the application traffic is temporally stopped in order to avoid deadlocks. But unfortunately this has negative impact on network service availability. Dynamic network reconfiguration is the process of changing from one routing function to another routing function while the network remains up and running. While performing dynamic network reconfiguration, the main challenge is to avoid deadlocks and provide network service availability along with reduced packet dropping rate. In this paper we demonstrate how dynamic reconfiguration is more efficient than the static reconfiguration for switch based networks

Disaster Recovery Services in Intercloud using Genetic Algorithm Load Balancer

Paradigm need to shifts from cloud computing to intercloud for disaster recoveries, which can outbreak anytime and anywhere. Natural disaster treatment includes radically high voluminous impatient job request demanding immediate attention. Under the disequilibrium circumstance, intercloud is more practical and functional option. There are need of protocols like quality of services, service level agreement and disaster recovery pacts to be discussed and clarified during the initial setup to fast track the distress scenario. Orchestration of resources in large scale distributed system having muli-objective optimization of resources, minimum energy consumption, maximum throughput, load balancing, minimum carbon footprint altogether is quite challenging. Intercloud where resources of different clouds are in align, plays crucial role in resource mapping. The objective of this paper is to improvise and fast track the mapping procedures in cloud platform and addressing impatient job requests in balanced and efficient manner. Genetic algorithm based resource allocation is proposed using pareto optimal mapping of resources to keep high utilization rate of processors, high througput and low carbon footprint.  Decision variables include utilization of processors, throughput, locality cost and real time deadline. Simulation results of load balancer using first in first out and genetic algorithm are compared under similar circumstances

Performance analysis and improvement of InfiniBand networks. Modelling and effective Quality-of-Service mechanisms for interconnection networks in cluster computing systems.

The InfiniBand Architecture (IBA) network has been proposed as a new industrial standard with high-bandwidth and low-latency suitable for constructing high-performance interconnected cluster computing systems. This architecture replaces the traditional bus-based interconnection with a switch-based network for the server Input-Output (I/O) and inter-processor communications. The efficient Quality-of-Service (QoS) mechanism is fundamental to ensure the import at QoS metrics, such as maximum throughput and minimum latency, leaving aside other aspects like guarantee to reduce the delay, blocking probability, and mean queue length, etc. Performance modelling and analysis has been and continues to be of great theoretical and practical importance in the design and development of communication networks. This thesis aims to investigate efficient and cost-effective QoS mechanisms for performance analysis and improvement of InfiniBand networks in cluster-based computing systems. Firstly, a rate-based source-response link-by-link admission and congestion control function with improved Explicit Congestion Notification (ECN) packet marking scheme is developed. This function adopts the rate control to reduce congestion of multiple-class traffic. Secondly, a credit-based flow control scheme is presented to reduce the mean queue length, throughput and response time of the system. In order to evaluate the performance of this scheme, a new queueing network model is developed. Theoretical analysis and simulation experiments show that these two schemes are quite effective and suitable for InfiniBand networks. Finally, to obtain a thorough and deep understanding of the performance attributes of InfiniBand Architecture network, two efficient threshold function flow control mechanisms are proposed to enhance the QoS of InfiniBand networks; one is Entry Threshold that sets the threshold for each entry in the arbitration table, and other is Arrival Job Threshold that sets the threshold based on the number of jobs in each Virtual Lane. Furthermore, the principle of Maximum Entropy is adopted to analyse these two new mechanisms with the Generalized Exponential (GE)-Type distribution for modelling the inter-arrival times and service times of the input traffic. Extensive simulation experiments are conducted to validate the accuracy of the analytical models

Control de congestión adaptativo en redes Infiniband

El uso de recursos compartidos en las redes de interconexión de alta performance puede provocar situaciones de congestión de mensajes que degradan notablemente las prestaciones, aumentando la latencia de trasporte y disminuyendo la utilización de la red. Hasta el momento las técnicas que intentan solucionar este problema utilizan la regulación de la inyección de mensajes. Esta limitación de la inyección traslada la contención de mensajes desde los conmutadores hacia los nodos fuente, incrementando el valor de la latencia promedio global, pudiendo alcanzar valores muy elevados. En este trabajo, proponemos una técnica de control de congestión para redes InfiniBand basada en un mecanismo de encaminamiento adaptativo que distribuye el volumen de comunicaciones entre diversas trayectorias alternativas quitando carga de la zona de congestión, lo que permite eliminarla. La experimentación realizada muestra la mejora obtenida en latencia y throughput, respecto al mecanismo de control de congestión original de InfiniBand basado en la regulación de la inyección. El mecanismo propuesto es totalmente compatible y no requiere que se modifique ningún aspecto de la especificación, debido a que se utilizan componentes de gestión definidos en el estándar InfiniBand