Resource allocation for query processing in grid systems: A survey

Grid systems are very useful platforms for distributed databases, especially in some situations in which the scale of data sources and user requests is very high. However, the main characteristics of grid systems such as dynamicity, large size and heterogeneity, bring new problems to the query processing domain such as resource discovery and resource allocation. In this paper, we provide a survey related to resource allocation methods for query processing In data grid systems. We provide a classification for existing studies considering their approaches to the resource allocation problem. We provide a synthesis of the studies and propose evaluations and comparisons for the different classes of studies. ©2012 CRL Publishing Ltd

Grid resource discovery based on web services

The size of grid systems has increased substantially in the last decades. Resource discovery in grid systems is a fundamental task which provides searching and locating necessary resources for a given process. Various different approaches are proposed in literature for this problem. Grid resource discovery using web services is an important approach which has resulted in many tools to become de facto standards of today's grid resource management. In this paper, we propose a survey of recent grid resource discovery studies based on web services. We provide synthesis, analysis and evaluation of these studies by classification. We also give a comparative study of different classes proposed

Dağıtık bir işletim sistemi için gerçek-zamanlı, çok-görevli bir çekirdek tasarımı

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.ABSTRACT Bu çalışmada, biribirinden bağımsız çalışabilen ve bir iletişim ağı ile bağlı bilgisayarlardan oluşan bir sistemin her istasyonunda tekrar edilebilecek, iletişim-tabanlı, çok-görevli, gerçek-zamanlı bir işletim sistemine ilişkin bir çekirdek yazılımı tasarlanmış ve gerçeklenmiştir. ABSTRACT In this study, a communication based, real-time multi-tasking kernel of a distributed operating system which would be dublicated at each station of a distributed real-time system that consists of autonamous computers connected by a communication network has been designed and realised. 1

A dynamic load balancing model for a distributed system

A communication protocol designed for fault tolerance in distributed real- time systems is implemented and a dynamic load balancing model is designed and implemented over this protocol. the protocol consists of cluster based, hierarchical rings which use synchronous communication. the rings are synchronous. At the lowest level in the hierarchy, there are clusters that consist of computing processors, called nodes. the higher level consists of the cluster representatives that manage the clusters of the lower level. There can be two or more levels in the hierarchy. Ring protocols in each cluster can work in parallel. Also, a fault tolerance mechanism is integrated to the protocol. the dynamic distributed load balancing module designed over the protocol aims to maximize the overall performance of the whole system by distributing the load submitted to the system efficiently and transparently among the nodes. While performing operations to achieve this goal, the module also considers the real-time constraints of the system

A hierarchical connected dominating set based clustering algorithm for mobile ad hoc networks

15th International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems, MASCOTS'07; Istanbul; Turkey; 24 October 2007 through 26 October 2007We propose a hierarchical Connected Dominating Set (CDS) based algorithm for clustering in Mobile Ad hoc Networks (MANETs). Our algorithm is an extension of our previous Connected Dominating Set Based Clustering (CDSC) Algorithm [1]. We extended the levels of the CDS to two levels and improved functionality at each level by providing additional rules to make sure that every node belongs to a single cluster. In the first level of the algorithm, the elements of the CDS are formed, based on CDSC Algorithm heuristics with improved functionality. The second level of the algorithm is executed among the CDS elements to find the second level CDS where each element belonging to the set represents a group of CDS elements, therefore a group of clusters. We show that this approach is more scalable and simpler to implement than a single level algorithm and that it also provides more balanced two level clusters due to its distributed nature. We also show that the number of levels of the algorithm can be extended to more than two layers providing more populated clusters, therefore providing a level of cluster and group membership structure within the MANET. This hierarchical groups can be used for different application needs at each level such as multi-cast communication or security purposes in MANETs

Implementation of a cluster based routing protocol for mobile networks

5th International Conference on Computational Science - ICCS 2005; Atlanta, GA; United States; 22 May 2005 through 25 May 2005We show the implementation and the simulation results of a hierarchical, cluster based routing protocol for mobile ad hoc networks using Parallel Virtual Machine (PVM). The network represented by a graph is partitioned into clusters by a graph partitioning algorithm and the shortest routes are first calculated locally in each cluster in the first srep. The simplified network which consists only of the nodes that have connections to other clusters called the neighbor nodes is then formed and the shortest routes are calculated for this simple network as the second step. A complete route between the two nodes of different clusters is formed by the union of intra-cluster and inter-cluster routes. We show the implementation results using PVM where a workstation represents a cluster and each node is a PVM process. The results obtained support the theoretical considerations where the efficiency increases by the number of clusters in use

A maximum degree self-stabilizing spanning tree algorithm

25th International Symposium on Computer and Information Sciences, ISCIS 2010; London; United Kingdom; 22 September 2010 through 24 September 2010Spanning trees are fundamental topological structures in distributed environments which ease many applications that require frequent communication between nodes. In this paper, we examine and compare two spanning tree construction algorithms which rely on classical and self stabilization approach. Then, we propose a new self-stabilizing spanning tree construction algorithm which uses maximum degree heuristic while choosing the root node. We show experimentally that our new algorithm provides smaller tree diameters than the two existing approaches with favorable run-times. © 2011 Springer Science+Business Media B.V

Time synchronization algorithms based on Timing-sync Protocol in Wireless Sensor Networks

23rd International Symposium on Computer and Information Sciences, ISCIS 2008; Istanbul; Turkey; 27 October 2008 through 29 October 2008Wireless Sensor Networks(WSN) are large scale networks of sensors running on wireless environment. For an application running on a WSN, gathered data by the sensors are time critical in most of the cases. However, almost all the nodes suffer from a problem named clock drift. This problem causes clock difference among nodes as time goes because the processors do not run exactly at the same speed. There are many proposed solutions to remedy this problem. TPSN (Timing-sync Protocol for Sensor Networks) is one of the effective protocols proposed to synchronize sensor networks. In this paper, we propose enhancements over TPSN to synchronize nodes in a wireless sensor network more effectively with a lower message complexity and higher precision

Resource allocation for query processing in grid systems: A survey

Grid systems are very useful platforms for distributed databases, especially in some situations in which the scale of data sources and user requests is very high. However, the main characteristics of grid systems such as dynamicity, large size and heterogeneity, bring new problems to the query processing domain such as resource discovery and resource allocation. In this paper, we provide a survey related to resource allocation methods for query processing In data grid systems. We provide a classification for existing studies considering their approaches to the resource allocation problem. We provide a synthesis of the studies and propose evaluations and comparisons for the different classes of studies. ©2012 CRL Publishing Ltd