Vote Assignment Research Articles

An automate failure recovery for synchronous distributed database system

Periodically, researchers have been sharing their constant attempts to improve the existing methods for data replication in distributed database system. The main goal is to work for an efficient distributed environment. An efficient environment may handle huge amount of data and preserve data availability. The occasionally failures in distributed systems will affect the end results, such as data loss, income loss etc. Thus, to prevent the data loss and guarantee the continuity of the business, many organizations have applied disaster recovery solutions in their system. One of the widely used is database replication, because it guarantees data safety and availability. However, disaster still can occur in database replication. Hence, an automatic failure recovery technique called distributed database replication with fault tolerance (DDR-FT) has been proposed in this research. DDR-FT uses heartbeat message for node monitoring. Subsequently, a foundation of binary vote assignment for fragmented database (BVAFD) replication technique has been used. In DDR-FT, the data nodes are continuously monitored while auto reconfiguring for automatic failure recovery. From the conducted experiments, it is proved that DDR-FT can preserve system availability. It shows that DDR-FT technique provides a convenient approach to system availability for distributed database replication in real time environment.

An Efficient Data Replication Technique with Fault Tolerance Approach using BVAG with Checkpoint and Rollback-Recovery

Data replication has been one of the pathways for distributed database management as well as computational intelligence scheme as it continues to improve data access and reliability. The performance of data replication technique can be crucial when it involves failure interruption. In order to develop a more efficient data replication technique which can cope with failure, a fault tolerance approach needs to be applied in the data replication transaction. Fault tolerance approach is a core issue for a transaction management as it preserves an operation mode transaction prone to failure. In this study, a data replication technique known as Binary Vote Assignment on Grid (BVAG) has been combined with a fault tolerance approach named as Checkpoint and Rollback-Recovery (CR) to evaluate the effectiveness of applying fault tolerance approach in a data replication transaction. Binary Vote Assignment on Grid with Checkpoint and Rollback-Recovery Transaction Manager (BVAGCRTM) is used to run the BVAGCR proposed method. The performance of the proposed BVAGCR is compared to standard BVAG in terms of total execution time for a single data replication transaction. The experimental results reveal that BVAGCR improves the BVAG total execution time in failure environment of about 31.65% by using CR fault tolerance approach. Besides improving the total execution time of BVAG, BVAGCR also reduces the time taken to execute the most critical phase in BVAGCRTM which is Update (U) phase by 98.82%. Therefore, based on the benefits gained, BVAGCR is recommended as a new and efficient technique to obtain a reliable performance of data replication with failure condition in distributed databases.

BVAGQ-AR for Fragmented Database Replication Management

Large amounts of data have been produced at a rapid rate since the invention of computers. This condition is the key motivation for up-to-date and forthcoming research frontiers. Replication is one of the mechanisms for managing data, since it improves data accessibility and reliability in the distributed database environment. In recent years, the amount of various data grows rapidly with widely available low-cost technology. Although we have been packed with data, we still have lacked of knowledge. Nevertheless, if the impractical data is used in database replication, this will cause waste of data storage and the time taken for a replication process will be delayed. This paper proposes Binary Vote Assignment on Grid Quorum with Association Rule (BVAGQ-AR) algorithm in order to handle fragmented database synchronous replication. BVAGQ-AR algorithm is capable for partitioning the database into disjoint fragments. Fragmentation in distributed database is very useful in terms of usage, reliability and efficiency. Managing fragmented database replication becomes a concern for the administrator because the distributed database is disseminated into split replica partitions. The result from the experiment shows that handling fragmented database synchronous replication through proposed BVAGQ-AR algorithm able to preserve data consistency in distributed environment.

Cost Saving Replication Technique in Data Grid

Replication is a useful technique for distributed database systems. An existing popular technique that has been used before are Read One-write-All Monitoring Synchronization Transactions System (ROWA-MSTS) and Hierarchical Replication Scheme (HRS). Nevertheless, these techniques have their flaws in terms of replication time taken. Subsequently, ROWA and HRS take more executing time in order to complete a transaction. It is because they have to copy their data to all sites. This research, Binary Voting Fragmented Database Replication (BVFDR) model, the some-data-to-some-sites technique is proposed. In order to handle transactions in the systems, BVFDR considers the neighbouring servers binary vote assignment to its logical grid structure on fragmented data copies. Therefore, it reduces storage capacity. An experiment has been carried out in three replicated servers. The results have been compared with existing techniques such ROWA and HRS. The result shows that BVFDR is able to preserve data consistency and outperformed in terms of time taken for a complete transaction compare to existing techniques. Overall, BVFDR able to handle fragmented data replication as well as capable to manage transaction management in distributed database environment by maintaining consistency of the data through the synchronization approach.

Managing Database Replication Using Binary Vote Assignment on Grid Quorum with Association Rule

Nowadays, many organizations deploy the database application systems in order to manage their business operation. Administrations is required to deliver up to date data to users who live distantly, thus replicated databases can be one solution to increase the business operations performance in the distributed environment. Even though data availability is increased, common existing replication strategies neglect the correlation among the different data files in a Distributed Database Systems. In this paper, Binary Vote Assignment on Grid Quorum with Association Rules (BVAGQ-AR) has been proposed to manage the database replication. This technique combines data replication and data mining approaches in order to decrease the job processing time. The result shows that BVAGQ-AR has the lowest job processing time compared to other techniques. BVAGQ-AR performs 66.548 ms to complete a transaction compared to BRS with 137.157 ms, HRS with 257.928 ms, and ROWA with 262.243 ms. From the results, it is proved that managing replication and transaction through the proposed BVAGQ-AR able to preserve data consistency with low job processing time.

An Efficient Data Replication Algorithm for Distributed Systems

This article describes how data replication plays an important role in distributed systems. It primarily focuses on the redundancy of data at two or more nodes, to achieve both fault tolerance and improved performance. Therefore, many researchers have proposed various data replication algorithms to manage the redundancy of data. However, they have not considered the faults that are associated with the nodes, such as permanent, transient and intermittent. Moreover, they have not incorporated any recovery approach to rejoin the failed nodes. Therefore, the authors propose a data replication algorithm, called dynamic vote-based data replication (DVDR). The main contribution of DVDR is to consider all types of faults and rejoin the failed nodes. DVDR is based on dynamic vote assignment among the connected nodes, and referred as passive and non-hierarchical one. The authors perform rigorous analysis of DVDR and compare with an existing dynamic vote assignment algorithm. The result shows the efficacy of the proposed algorithm.

Managing Fragmented Database Using BVAGQ-AR Replication Model

One of the mechanisms for managing data is replication since it improves data access and reliability. However, the amount of various data grows rapidly since technology is widely available at a low-cost. Problem arises when the database is packed with data, but it has lacked of knowledge. If the unreasonable data is used in database replication, it will cause waste of data storage and delay the time taken for a replication process. This paper proposes a new algorithm namely Binary Vote Assignment on Grid Quorum with Association Rule (BVAGQ-AR) to handle fragmented database replication. BVAGQ-AR algorithm is capable of partitioning the database into disjoint fragments. Handling fragmented database replication becomes challenging issue to administrator since the distributed database is disseminated into split partitions or fragments. This paper will discuss about how to build reliable system by using the proposed BVAGQ-AR algorithm for distributed database fragmentation. The result shows that managing fragmented database replication through proposed BVAGQ-AR algorithm able to preserve data consistency.

Losing Bargain: Why Winner-Take-All Vote Assignment is the Electoral College's Least Defensible Feature

The electoral college is usually considered as a single institution that, in contrast to a system of direct election, mediates the popular will and advances countermajoritarian principles. To its critics, this role is a destructive one; the electoral college thwarts the foundational democratic idea that all votes should count equally and the majority’s choice should lead. By contrast, defenders of the electoral college argue that it is a deliberately crafted institution whose deviations from nationwide popular sentiment are part of its design. Yet the electoral college is not a single institution but a combination of procedures. The electoral college produces results potentially different from those that would be achieved by direct election through several distinct mechanisms, including the two-vote bonus given to all states, the assignment of electoral votes based on total population rather than voters, and the award of state electoral votes on a winner-take-all basis. Of these mechanisms, the use of winner-take-all rules stands out as the least defensible. In contrast to other aspects of the electoral college, winner-take-all systems were not part of the electoral college’s original design and were adopted haphazardly at the state level, without systematic consideration of their national consequences. Further, winner-take-all rules cause considerable harm by contributing most strongly to the risk of popular/electoral splits, by creating incentives for fraud, voter suppression, and other undesirable campaign tactics, and by arbitrarily privileging some voters’ preferences at others’ expense. As a result, advocates for electoral college reform should make abolition of winner-take-all central to both their critiques of the current process and their evaluation of reform proposals.

Managing Fragmented Database Replication for Mygrants Using Binary Vote Assignment on Cloud Quorum

Replication in distributed database is the process of copying and maintaining database objects in multiple databases that make up a distributed database system. In this paper, we will manage fragmented database replication and transaction management for Malaysian Greater Research Network (MyGRANTS) using a new proposed algorithm called Binary Vote Assignment on Cloud Quorum (BVACQ). This technique will combine replication and fragmentation. Fragmentation in distributed database is very useful in terms of usage, efficiency, parallelism and also for security. This strategy will partition the database into disjoint fragments. The result shows that managing replication and transaction through proposed BVACQ able to preserve data consistency. It also increases the degrees of parallelism. This is because by using fragmentation, replication and transaction can be divided into several subqueries that operate on the fragments.

Handling Fragmented Database Replication through Binary Vote Assignment Grid Quorum

Problem statement: Organizations critically needed to supply recent data to users who may be geographically remote, while at the same time handle a volume request of distributed data around multiple sites. The storage, availability and consistency are important issues to be addressed in order to allow distributed users efficiently and safely access data from many different sites. Approach: Data replication is a way to deal with this problem since it provides user with fast, local access to shared data and protects availability of applications because alternate data access options exist. Handling fragmented database replication becomes challenging issue to administrator since the distributed database was scattered into split replica partitions or fragments. Results: This study presented a new mechanism on how to handle the fragmented database replication through the Binary Vote Assignment on Grid Quorum (BVAGQ). We address how to build reliable system by using the proposed BVAGQ for distributed database fragmentation. Conclusion: The result shows that managing fragmented database replication and transaction through proposed BVAGQ is able to preserve the data consistency.

Managing Educational Resource - Student Information Systems Using BVAGQ Fragmented Database Replication Model

Significant and urgent solutions are required in order to manage educational resource efficient and effective. Data replication is one of the key components to manage the huge of resources in data grid architecture as it enhances data access and reliability. Replication provides user with fast, local access to shared data, and increased availability of applications because alternate data access options exist. In this paper, we present on how to manage fragmented database replication and transaction for educational resources-Student Information System (SIS) by using Binary Vote Assignment on Grid Quorum (BVAGQ) fragmented database replication model. Furthermore, fragmentation in distributed database is very useful in terms of usage, reliability and efficiency. In particular, BVAGQ able to partition the database into disjoint fragments. The result shows that managing replication and transaction through proposed BVAGQ able to preserve data availability and consistency. It also increases the degrees of parallelism. This is because by using fragmentation, replication and transaction can be divided into several subqueries that operate on the fragments.

Strategic Passing and Opinion Assignment on the Burger Court

Previous research indicates that U.S. Supreme Court justices who are likely to control opinion assignments may withhold votes in an initial round of conference voting in circumstances that suggest that this behavior has strategic origins. Specifically, scholars have suggested that justices may pass in conference voting to gain control over the opinion assignment. This study extends this literature by developing a theory of the relationship between strategic passing in a conference vote and opinion assignment, which is assessed through a quantitative analysis of opinion assignments made by Chief Justice Burger. Specifically, we argue that justices selected to write opinions by those who have passed to strategically join a majority will be more ideologically peripheral compared to the majority coalition as a whole than justices who are assigned to write opinions following conference votes cast in order of seniority. Consistent with this theory, we find that Chief Justice Burger, indeed, made opinion assignments that diverged more strongly from the ideological composition of the Court's majority when he passed in conference compared with opinion assignments he made when he voted in order of seniority.

Managing transactions on grid-neighbour replication in distributed systems

Managing transactions is very important in distributed databases in order to preserve data consistency and reliability of the systems. This paper presents a new design to manage transactions on neighbour replication in a distributed database system. We address how to build a reliable system for managing transactions on a neighbour replication grid (NRG) in terms to preserve the data consistency and support fault-tolerance. We first recall the model and technique of NRG that impose neighbours binary vote assignment to its logical grid structure on data copies. We extend our work in managing transactions to normal and failure cases. Finally, the implementation of the system is presented.

Binary vote assignment on a grid for efficient access of replicated data

Data replication can be used to improve the availability of data in a distributed database system. In such a system, a mechanism is required to maintain the consistency of the replicated data. Grid structure (GS) technique based on quorum is one of the latest solutions for performing this while providing a high availability of the system. It was shown in the previous study, that it still requires a bigger number of copies be made available to construct a quorum. So it is not suitable for the large systems. In this paper, we propose a technique called the binary vote assignment on grid (BVAG) technique by considering only neighbors have the replicated data. In comparison to the GS technique, BVAG requires lower communication cost for an operation, while providing higher data availability, which is preferred for large systems.

Optimal binary vote assignment for replicated data

Data replication can be used to improve the availability of data in a distributed database system. In such a system, a mechanism is required to maintain the consistency of the replicated data. Weighted voting is a popular solution for maintaining the consistency. The performance of a voting system is determined by the vote assignment. It was shown in previous studies that finding the optimal solution among nonnegative integer vote assignments requires O(2 N 2 ) time. So it is not suitable to find the optimal integer vote assignment (OIVA) for large systems. In this paper, we propose the optimal binary vote assignment (OBVA) considering only binary vote assignments. It is shown that OBVA can achieve nearly the same availability of OIVA. On the other hand, OBVA requires only O( N 2) time, which is preferred for large systems.

New Heuristics for the Multidimensional Vote Assignment Problem

Vote assignments are being used for the design of fault tolerant systems. They work in such a way that every node in a computer network gets assigned a certain number of votes. Furthermore, a quorum is defined. A transaction can only take place if the number of votes collected is greater than or equal to the quorum. These single dimensional vote assignments provide a compact representation of certain antichains, namely those which consist of the minimal sets of nodes achieving the quorum. Multidimensional (MD) vote assignments are a generalization of single dimensional vote assignments. In contrast to single dimensional vote assignments, MD vote assignments have the important property that every antichain has a corresponding MD vote assignment and vice versa. For the efficient design of fault tolerant systems, it is important that the dimension of a MD vote assignment is as small as possible. We introduce some new heuristics for calculating a MD vote assignment which perform better than the heuristics known so far.

A task migration algorithm for heterogeneous distributed computing systems

Most load balancing schemes are based on the assumption that all processors in a distributed computing system (DCS) have similar processing power and workload. However, as technology continues to advance, networks have become more likely to contain processors of different capabilities and configurations. The proposed load balancing method is based on the coterie, a tool first used in mutual exclusion and vote assignment. This paper describes how the unique properties of coteries allow the underlying protocol to be tailored to the capabilities of the individual nodes in a connected network. In general, each processor communicates with only a subset of the other processors in the network, keeping message traffic relatively low. The coterie allows these subsets to be constructed according to a more thoughtful method – one that is designed to better meet the needs of networks of varying characteristics. It is also shown that the proposed method will always perform task migration whenever possible i.e., if at least one lightly loaded processor and at least one heavily loaded processor exist in the network, task migration will occur. Further, an extension of our algorithm to provide fault tolerance is given: when a processor fails, the network can continue to function with a modified system configuration.

Voting as the optimal static pessimistic scheme for managing replicated data

This paper investigates the problem of finding an optimal static pessimistic replica control scheme. It has been widely accepted that coteries (proposed by Garcia-Molina and Barbara) provide the most general framework for such schemes. We demonstrate that voting schemes, a very small subset of static pessimistic schemes, are optimal for fully connected networks with negligible link failure rates, as well as for Ethernet systems. We also show that voting is not optimal for somewhat more general systems. We propose a modification of the algorithm of Z. Tong and R.Y. Kain (1988) for computing optimal voting in operation independent case, so that it runs in linear (rather than exponential) time. Finally, we propose the first efficient algorithm for computing the optimal vote assignment and appropriate thresholds for fully connected networks when relative frequencies of read and write operations are known. We also extend this result to Ethernet systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A short technical paper: Determining whether a vote assignment is dominated

One way to achieve mutual exclusion in a distributed system is to assign votes to each site in the system. If the total number of votes is odd, the assignment is known to be nondominated, meaning that no other assignment can provide strictly greater access and still achieve mutual exclusion. We characterize in this note dominated even-totaled vote assignments. As a consequence, we obtain that the problem of determining whether an even-totaled vote assignment is dominated is trivial if each site is assigned exactly one vote; however, the problem is NP-complete in general.

Vote assignments in weighted voting mechanisms

It is shown that voting can provide the maximum reliability if all nodes have reliability p>or=0.5. Thus, a system designer only needs to consider vote assignments in implementing mutual exclusion mechanisms. Some effective vote assignment algorithms are proposed. Neglecting link failures, it is found that the voting weight for each node can be determined by computing a logarithmic function of local information. Voting operations are formally defined, and an optimization objection function is formulated. A sufficient condition for optimal vote assignment and optimal sets of groups is presented, and it is shown that predefining a set of groups to achieve mutual exclusion is not feasible for a large system. Some algorithms generating optimal or suboptimal assignments for systems with perfect links are proposed. Some variations for systems with imperfect links are discussed, along with some comparisons of the new algorithms against previous algorithms proposed for the problem. >