Single Point Of Failure Problem Research Articles

Khorramshahr: A scalable peer to peer architecture for port warehouse management system

In the growing trend of globalization, the logistics and transportation play the key role in many industries. Products are shipped from one country to another. The heart of this transportation is the port, where large quantities of goods are imported and exported on daily bases. Applying Internet of Things (IoT) technologies to port warehouses is the main area of this work. Centralized warehouse management systems are prone to a single point of failure problem and are not fault tolerant. They have also limited scalability. Another issue is that the port warehouses may run by different companies and the privacy of the detailed product information must be preserved. In this paper, we design an IoT based architecture for warehouse management, according to the facts gathered from the Khorramshahr port. The main issues that this paper tries to address are: scalability, fault tolerance, and privacy. The devised architecture is named Khorramshahr (named after the name of the port). The tailored version of Chord architecture is exploited for a Distributed Hash Table (DHT), which inherits the required scalability and fault tolerance. According to the devised architecture, each company can solely manage its dedicated nodes and preserve the privacy. To boost the lookup process the design is enhanced by Bloom filter and Quotient filter. Moreover, to gain performance the architecture uses a hybrid approach, which combines both the client server and the peer to peer paradigms. To evaluate the performance, the DHT of the architecture is simulated by OMNet++ and OverSim. The simulation results show that by the scaling the number of terminals from 25 to 250 the access time for an item increases only 38%. Besides, the increase in the number of requests from 10,000 to 50,000 depicts 5% and 10% improvement respectively for the lookup message latency compared to the ODSA. The simulation results also exhibit lower false positive rate for the Quotient filter approach, which makes it the first implementation candidate. Only in cases with strict constraints on memory consumption the Bloom filter approach is favored.

Hierarchical Multi-Authority and Attribute-Based Encryption Friend Discovery Scheme in Mobile Social Networks

In mobile social networks, to guarantee the security and privacy in the friend discovery process, we propose a hierarchical multi-authority and attribute-based encryption (ABE) friend discovery scheme based on ciphertext-policy (CP)-ABE. It employs character attribute subsets to achieve flexible fine-grained access control, which solves the problem of single-point failure and performance bottleneck. Performance analysis demonstrates the superiority of our scheme in terms of system initialization time and key generation time.

A Privacy-Preserving Health Data Aggregation Scheme

Patients’ health data is very sensitive and the access to individual’s health data should be strictly restricted. However, many data consumers may need to use the aggregated health data. For example, the insurance companies needs to use this data to setup the premium level for health insurances. Therefore, privacy-preserving data aggregation solutions for health data have both theoretical importance and application potentials. In this paper, we propose a privacy-preserving health data aggregation scheme using differential privacy. In our scheme, patients’ health data are aggregated by the local healthcare center before it is used by data comsumers, and this prevents individual’s data from being leaked. Moreover, compared with the existing schemes in the literature, our work enjoys two additional benefits: 1) it not only resists many well known attacks in the open wireless networks, but also achieves the resilience against the human-factor-aware differential aggregation attack; 2) no trusted third party is employed in our proposed scheme, hence it achieves the robustness property and it does not suffer the single point failure problem.

Preliminary design and thermal analysis of a liquid metal heat pipe radiator for TOPAZ-II power system

An alkali metal heat pipe radiator is proposed for the Russian TOPAZ-II space reactor power system to replace the original pumped loop radiator with three advantages. First, the single point failure problem of the original radiator can be avoided. Second, because only the NaK manifold needs to be armored, the specific mass would be reduced and the reliability and survivability can be improved. Third, the heat pipe has nearly isothermal characteristics and high heat transfer capabilities. In the present paper, the high temperature heat pipes using potassium as working fluid, wire screen mesh as wick layer, made of stainless steel are adopted to remove waste heat by radiation. An integral carbon-carbon fin covering and connecting heat pipes as whole heat transfer radiator is selected for its higher thermal conductivity and lower self-weight. A detailed steady state numerical calculation using the finite element method coupled with finite difference method is performed to predict the heat rejection characteristics of the heat pipe radiator. Heat transfer performances of the new concept heat pipe radiator and the pumped loop radiator are compared with key parameters. The results show that the designed heat pipe radiator satisfies the waste heat rejection requirements of the TOPAZ-II power system under the normal operating conditions and has an ideal redundancy. The isothermal and safety of heat pipe radiator is also better than that of pumped loop radiator.

A Fault Tolerant Parallelism Approach for Implementing High-Throughput Pipelined Advanced Encryption Standard

Advanced Encryption Standard (AES) is the most popular symmetric encryption method, which encrypts streams of data by using symmetric keys. The current preferable AES architectures employ effective methods to achieve two important goals: protection against power analysis attacks and high-throughput. Based on a different architectural point of view, we implement a particular parallel architecture for the latter goal, which is capable of implementing a more efficient pipelining in field-programmable gate array (FPGA). In this regard, all intermediate registers which have a role for unrolling the main loop will be removed. Also, instead of unrolling the main loop of AES algorithm, we implement pipelining structure by replicating nonpipelined AES architectures and using an auto-assigner mechanism for each AES block. By implementing the new pipelined architecture, we achieve two valuable advantages: (a) solving single point of failure problem when one of the replicated parts is faulty and (b) deploying the proposed design as a fault tolerant AES architecture. In addition, we put emphasis on area optimization for all four AES main functions to reduce the overhead associated with AES block replication. The simulation results show that the maximum frequency of our proposed AES architecture is 675.62[Formula: see text]MHz, and for AES128 the throughput is 86.5[Formula: see text]Gbps which is 30.9% better than its closest existing competitor.

A Hierarchical and Role Based Secure Routing Protocol for Mobile Wireless Sensor Networks

Nodes in wireless sensor networks are highly resource constrained and topology of such networks remains highly dynamic due to sudden death of sensor nodes and break of links. When mobility to such nodes is introduced, it gives rise to a highly complex network system since the topology becomes even more dynamic. Providing security in the routing layer of wireless sensor network is a highly critical issue mainly due to the stringent resource constraints and dynamic topology. In this paper, we propose a Secure Hierarchical and Role based Routing Protocol for Mobile Wireless Sensor Network (SHaRP) which is a combination of symmetric and asymmetric cryptographic approach. In the SHaRP framework, the sensor field is divided into some logical clusters and each cluster contains nodes with different roles such as ordinary sensor node (OSN), cluster head (CH) and gateway node (GN). Different keys are used by the nodes with distinct roles for message encryption and message decryption. The overall security has been entrusted on different roles in a distributed manner instead of relying on one authority and that is why this approach is safe from single point of failure problem. This also enhances the security in the network system. In this paper, we focus more on various security aspects in the routing process rather than the issues like cluster formation and role distribution. We shift most of the computing overhead to the base station as it is assumed to be a resourceful and reliable node. This obviously improves the energy efficiency of the protocol. We also report a security analysis along with implementation issues of the proposed protocol.

SECURE DATA STORAGE IN MULTI CLOUD ENVIRONMENT USING APACHE HADOOP

Cloud computing and Hadoop has become a new distributed storage model for most of the organizations, Industries etc. It provides a pay per use model in which customer has to only pay for the data he is storing on the cloud. However, relying on a single cloud storage provider has resulted in problems like vendor lock in. Therefore multi cloud environment is used to address the security and the data availability problems. In this paper, we proposed a system that uses Hadoop computing platform in multi cloud domain for storing customer’s data reliably. Hadoop is used to conquer single point of failure problem which has been main issue in centralized environment as well as to deal with remote uploading.

Decentralized Plan-Free Semantic-Based Service Composition in Mobile Networks

The inefficiency of one-to-one matching of user requirements to a single service has given rise to service composition. Service composition allows simple services to be dynamically combined into more complex services. In mobile environments, service discovery and integration involves cooperation between various service nodes where reliance on a centralized service registry introduces efficiency and single point of failure problems. Plan- and workflow-based composition solutions restrict service discovery to defined abstract models. Semantic similarity measurements play an important role in service integration. In this paper we introduce a semantic similarity and semantic nearness service composition method. The objective of our work is to free service nodes from adherence to restrictive composition plans. Our work also enables compositions to succeed in dynamic environments through a decentralized solution even when nodes are unaware of nearby service nodes. This paper presents a service composition solution that semantically advances composition paths towards users’ needs with each service hop while guaranteeing a user-acceptable QoS level. Simulation results showcase the effectiveness of the presented solution and its compatibility with underlying service discovery methods.

An intelligent path recommendation protocol (ICOD) for VANETs

This work introduces a novel, intelligent, real-time, distributed, and flexible path recommendation protocol. We refer to the introduced protocol as an Intelligent path recommendation protocol (ICOD). This protocol aims to find the best path towards each destination in any grid-based layout area. The path is reactively reconfigured at each road intersection; this is based on the real-time traffic status of the Surrounding Road Segments (SRSs) of that intersection: i.e., any road segment that starts or ends with the road intersection. In order to handle the centralized behavior problems (i.e., bottleneck, single point of failure, etc.) which appeared in the previous path recommendation protocols, ICOD has constructed the path towards each destination in a distributed manner. Three different variants of ICOD are thus introduced to enable flexible selection of the best path towards each destination according to the following driver concerns and priorities: congestion avoidance, economical and context-aware. The congestion avoidance variant aims to reduce the traffic congestion, by recommending each vehicle to take the least congested path towards its destination. The economical variant recommends the best economical path in terms of fuel consumption and gas emission parameters of each candidate path. Finally, the context-aware variant considers the context of each traveled road segment while selecting the desired path. Thus, the located services and the road conditions are considered. We report on the performance of these different variants of ICOD and compare them with previous path recommendation protocols, using an extensive set of scenarios and experiments implemented by NS-2. From these experimental results, ICOD is shown to exhibit a good performance in terms of its ability to recommend the best path which decreases the delay of each vehicle by 50% in the process of obtaining the directions towards its destination; it also eliminates the bottleneck and single point of failure problems.

Proxy-Based Security-Feedback Trust Model in MP2P Network

Trust problem is a key issue for Mobile P2P (MP2P) network security. In MP2P network, terminals addressing mode, communication way and display identifier are different to traditional P2P network. Some security issues such as: malicious slander and collusion, free ride phenomenon, are even more serious compared to traditional P2P network. Aimed at these above issues, a Proxy-based Security-Feedback Trust Model (PSTM) is proposed. Different types of terminals access to different proxy servers to shield the discrepancy between different terminal equipments on MP2P equipment access network layer. Meanwhile, proxy servers can reduce the problem of single point failure with method of trust related tables backup and recovery. Certificate Feedback Raters identification and qualification through security resource-selection protocol then integrate trust information according to similarity of terminal and resource types with weight. Furthermore, set global contribution value and evaluation value in multi-granularity trust computation to motivate mobile peers honest feedbacks. Divide mobile peers direct trust value into peer-oriented and resource-oriented values to make trust feedbacks more authentic. Simulation experiments show that PSTM can reduce malicious slander and collusion effectively. It also can restrain self-ish peers free ride behaviors and increase successful cooperation rate of high-contributed nodes in MP2P network.

Efficient topology construction for RPL over IEEE 802.15.4 in wireless sensor networks

IEEE 802.15.4-2006 represents a widely used standard for multihop wireless sensor networks. However, the standard exploits a tree structure in the MAC layer, which may lead to network partitions even after a single link or node failure, i.e. the well known single point of failure problem. Besides, the single path approach avoids the routing protocol to select by itself a next hop based on its own criteria. Moreover, transmissions must be appropriately scheduled in the IEEE 802.15.4 cluster-tree to avoid collisions. In this paper, we propose to modify the cluster-tree structure into a Cluster-Directed Acyclic Graph (DAG) to improve the robustness and the topology redundancy at the MAC layer. We also present a simple greedy scheduling algorithm integrated with the IEEE 802.15.4 MAC mechanisms. Simulations show that the proposed mechanisms optimize the MAC layer for multihop topologies. In particular, the routing protocol (e.g. RPL) is able to exploit efficiently the cluster-DAG and to reduce the number of packet losses and the end-to-end delay. Last but not least, the cluster-DAG structure leads globally to energy savings by reducing the number of transmissions at the MAC layer.

An Efficient Algorithm for Resource Allocation in Parallel and Distributed Computing Systems

Resource allocation in heterogeneous parallel and distributed computing systems is the process of allocating user tasks to processing elements for execution such that some performance objective is optimized. In this paper, a new resource allocation algorithm for the computing grid environment is proposed. It takes into account the heterogeneity of the computational resources. It resolves the single point of failure problem which many of the current algorithms suffer from. In this algorithm, any site manager receives two kinds of tasks namely, remote tasks arriving from its associated local grid manager, and local tasks submitted directly to the site manager by local users in its domain. It allocates the grid workload based on the resources occupation ratio and the communication cost. The grid overall mean task response time is considered as the main performance metric that need to be minimized. The simulation results show that the proposed resource allocation algorithm improves the grid overall mean task response time. (Abstract)

A Hierarchical Load Balancing Policy for Grid Computing Environment

With the rapid development of high-speed wide-area networks and powerful yet low-cost computational resources, grid computing has emerged as an attractive computing paradigm. It provides resources for solving large scientific applications. It is typically composed of heterogeneous resources such as clusters or sites at different administrative domains connected by networks with widely varying performance characteristics. The service level of the grid software infrastructure provides two essential functions for workload and resource management. To efficiently utilize the resources at these environments, effective load balancing and resource management policies are fundamentally important. This paper addresses the problem of load balancing and task migration in grid computing environments. We propose a fully decentralized two-level load balancing policy for computationally intensive tasks on a heterogeneous multi-cluster grid environment. It resolves the single point of failure problem which many of the current policies suffer from. In this policy, any site manager receives two kinds of tasks namely, remote tasks arriving from its associated local grid manager, and local tasks submitted directly to the site manager by local users in its domain, which makes this policy closer to reality and distinguishes it from any other similar policy. It distributes the grid workload based on the resources occupation ratio and the communication cost. The grid overall mean task response time is considered as the main performance metric that need to be minimized. The simulation results show that the proposed load balancing policy improves the grid overall mean task response time.

Minimum Latency Gossiping in Radio Networks

We studied the minimum latency gossiping (all-to-all broadcast) problem in multihop radio networks defined as follows: Each node in the network is preloaded with a message and the objective is to distribute each node's message to the entire network with minimum latency. We studied this problem in the unit-size message model and the unit disk graph model. The unit-size model means different messages cannot be combined as one message, and the unit disk graph model means a link exists between two nodes if and only if their euclidean distance is less than 1. The minimum latency gossiping problem is known to be NP-hard in these two models. In this work, we designed a gossiping scheme that significantly improved all current gossiping algorithms in terms of the approximation ratio. Our work has approximation ratio 27, a great improvement of the current state-of-the-art algorithm (which has ratio 1,947). We also discussed the single point of failure problem and its impact on our approximation ratio. We designed an amended gossiping algorithm with ratio 27 in case of a nonsource node failure. We also designed an amended gossiping algorithm with ratio 29 in case of source failure.

Semi-trusted Collaborative Framework for Multi-party Computation

Data sharing is an essential process for collaborative works particularly in the banking, finance and healthcare industries. These industries require many collaborative works with their internal and external parties such as branches, clients, and service providers. When data are shared among collaborators, security and privacy concerns becoming crucial issues and cannot be avoided. Privacy is an important issue that is frequently discussed during the development of collaborative systems. It is closely related with the security issues because each of them can affect the other. The tradeoff between privacy and security is an interesting topic that we are going to address in this paper. In view of the practical problems in the existing approaches, we propose a collaborative framework which can be used to facilitate concurrent operations, single point failure problem, and overcome constraints for two-party computation. Two secure computation protocols will be discussed to demonstrate our collaborative framework.

A Decentralized Group Key Management Scheme for the Decentralized P2P Environment

In this letter, we propose a decentralized group key management algorithm called DECLKH, which combines the logical key hierarchy (LKH) and the tree-based group Diffie- Hellman (TGDH) schemes. LKH is a centralized key distribution scheme, and thus, lacks fault-tolerance. On the other hand, TGDH is relatively inferior in terms of performance to LKH although it is fault-tolerant. The proposed algorithm, <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DECLKH</i> , solves the single point of failure problems of LKH with much more enhanced performance than TGDH.

A secure group key management scheme for hierarchical mobile ad hoc networks

In this paper, we present a secure group key management scheme for hierarchical mobile ad hoc networks. Our approach aims to improve both scalability and survivability of group key management for large-scale wireless ad hoc networks. To achieve our goal, we propose the following approaches: (1) a multi-level security model, which follows a modified Bell-La Padula security model that is suitable in a hierarchical mobile ad hoc networking environment, and (2) a decentralized group key management infrastructure to achieve such a multi-level security model. Our approaches reduce the key management overhead and improve resilience to any single point failure problem. In addition, we have developed a roaming protocol that is able to provide secure group communication involving group members from different groups without requiring new keys; an advantage of this protocol is that it is able to provide continuous group communication even when the group manager fails.

P2PGrid: integrating P2P networks into the Grid environment

AbstractThe current Grid architecture suffers from high complexity, inefficiency in leveraging common PC capabilities, and the single point of failure problem originated from Grid's client–server mode of interaction. In this paper, we propose an approach to solve the problems by incorporating peer‐to‐peer (P2P) networks with the Grid environment. A two‐layer integration model is proposed, which consists of a Grid layer and an underlying P2P layer that can be accessed from but is not limited to the Grid layer. A prototype implementation of the model, called P2PGrid, has been developed and experimented with example applications built on the platform. The results show that the complexity for common PCs to participate in the Grid can be greatly reduced, the resource aggregation efficiency has been increased, and the single point of failure problem can be solved by using P2P mode of communication in the Grid environment. Copyright © 2006 John Wiley &amp; Sons, Ltd.

A self-organizable topology maintenance protocol for mobile group communications in mobile next-generation networks

The explosive growth of mobile and wireless communications has attracted interests in the integration of mobile and wireless networks with wired ones and the wired Internet in particular. In order to deal with the scalability and reliability issues for group communication services in such a network environment, many existing protocols divide the whole group into subgroups and organize them into a tree-based hierarchy. A special node in each subgroup is responsible for collecting acknowledgement messages and locally retransmitting lost messages within the subgroup. However, the tree-based hierarchy has the single point of failure problem, which may seriously affect the performance of group communications. We propose a RingNet hierarchy of proxies that is a combination of logical trees and logical rings. The proposed hierarchy has the self-organization property because it can heal itself as quickly as possible in the presence of failures. Therefore, it has no single point of failure problem. We formally prove that, with high probability of 99.899%, the proposed hierarchy with up to 10 000 proxies directly attached by a large number of mobile hosts only needs simple and efficient procedures to repair broken logical rings when the node failure probability is bounded by 0.1%. We also validate the proposed protocol by extensive simulations, which show that the proposed protocol scales very well when the size of the network becomes large, and that it is highly resilient to failures when the node failure probability becomes large.

Proxy PNNI augmented routing (proxy PAR)

ATM networks often carry other popular communication protocols such as TCP/IP. LAN emulation techniques, with LANE and MPOA being the most prominent ones, make it possible to support existing applications, but do not take advantage of many ATM capabilities. Furthermore, such server-based solutions often suffer from a single point of failure problems. PNNI augmented routing (PAR), based on private network-network interface (PNNI), enables ATM and TCP/IP to be better integrated than in an emulation environment. In addition to that, proxy PAR has been introduced as minimal version of PAR that gives ATM attached devices the ability to interact with PNNI devices without the complexity associated with a full PAR implementation. Proxy PAR has been conceived as a client/server interaction in which the client side is much simpler than the server side, permitting fast implementation and deployment in existing IPv4 devices. The main purpose of proxy PAR is to allow non-ATM devices to use the flooding mechanisms provided by PNNI for registration and automatic discovery of services offered. Proxy PAR capable servers support filtering based on virtual private network (VPN) IDs, IP protocols and address prefixes. This enables, for example, routers in a certain VPN running OSPF to find their neighboring routers without the manual configuration implied by other technologies such as frame relay.