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Secure transaction management protocols for MLS/DDBMS

3rd International Conference on Information system Security (ICISS 2007)

作者： Kaur, Navdeep Singh, Rajwinder Misra, Manoj Sarje, A. K. Indian Inst Technol Dept Elect & Comp Engn Roorkee Uttar Pradesh India

ISBN: (纸本)9783540770855

Majority of the research in multilevel secure database management systems (MLS/DBMS) focuses primarily on centralized database systems. However, with the demand for higher performance and higher availability, database systems have moved from centralized to distributed architectures, and the research in multilevel secure distributed database management systems (MLS/DDBMS) is gaining more and more prominence. Traditional transaction management protocols (i.e., concurrency control and commit protocols) are important components of database systems. The most important issues for these protocols in MLS database system are the covert channel problem [2] and starvation of high security level transactions [10]. To address these problems, first we propose new correctness criteria for multilevel secure multiversion concurrency control protocol, called read-down conflict serializability. It is the extended definition of one-copy serial (or1-serial) that allows a transaction to read older versions, if necessary. If a concurrency control protocol allows transaction to read older versions, we can obtain better throughput and response time than the traditional multiversion concurrency control protocols. We show that multiversion schedule based upon proposed criteria is also one-copy serializable. Secondly, this paper proposes a secure multiversion concurrency control protocol for MLS/DDBMSs that is only free from covert channels but also do so without starving high security level transactions, in addition to ensure the proposed serializability. Further, in distributed database systems, an atomic commitment protocol is needed to terminate distributed transactions consistently. To meet MLS requirements and to avoid database inconsistencies 2PC commit protocol is also modified.

关键词： multilevel security concurrency control commit protocol covert channel distributed database system

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Introduction to a system for distributed databases (SDD-1)

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ACM Transactions on database systems (TODS) 1980年第1期5卷 1-17页

作者： Rothnie, J.B. Bernstein, P.A. Fox, S. Goodman, N. Hammer, M. Landers, T.A. Reeve, C. Shipman, D.W. Wong, E. Computer Corporation of America 575 Technology Square Cambridge MA 02139 United States Center for Research in Computing Technology Aiken Computation Laboratory Harvard University Cambridge MA 02138 United States Massachusetts Institute of Technology Laboratory for Computing Science 545 Technology Square Cambridge MA 02139 United States Department of Electrical Engineering and Computer Sciences University of California Berkeley CA 94720 United States

The declining cost of computer hardware and the increasing data processing needs of geographically dispersed organizations have led to substantial interest in distributed data management. SDD-1 is a distributed database management system currently being developed by Computer Corporation of America. Users interact with SDD-1 precisely as if it were a nondistributed database system because SDD-1 handles all issues arising from the distribution of data. These issues include distributed concurrency control, distributed query processing, resiliency to component failure, and distributed directory management. This paper presents an overview of the SDD-1 design and its solutions to the above problems. This paper is the first of a series of companion papers on SDD-1 (Bernstein and Shipman [2], Bernstein et al. [4], and Hammer and Shipman [14]). © 1980, ACM. All rights reserved.

关键词： concurrency control database reliability distributed database system query processing relational data model

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Investigating the effect of an attack on a distributed database

Investigating the effect of an attack on a distributed datab...

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7th Annual IEEE Information Assurance Workshop

作者： Samara, Rami Panda, Brajendra Univ Arkansas Dept Comp Sci & Comp Engn Fayetteville AR 72701 USA

ISBN: (纸本)9781424401291

After an attack on a database system, evaluation of damage must be performed as soon the attack is identified. Otherwise, the initial damage will spread to other parts of the database via valid transactions, consequently resulting in denial-of-service. Damage assessment in a distributed database system is a complicated task due to intricate transaction relationships among distributed sites. In these systems, when any sub-transaction reads a damaged data at any site, the entire transaction of which the sub-transaction is a part, is considered affected by the damage. Hence, the data items updated by that transaction irrespective of sites are also considered damaged. This research focuses on damage assessment procedure for distributed database systems and uses a two-pass algorithm to obtain the final fist of affected data items. The advantages of this method are: (1) the process is fully distributed in the sense that every site will execute the same algorithm, (2) the amount of data to be exchanged between the sites is minimized to the list of affected items at each site instead of the entire log, and (3) the local damage assessors can be executed in parallel at their respective sites.

关键词： distributed database system transaction dependency dependency graphs local logs malicious transactions affected transactions damaged data items

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RC-OCP: Reverse Coordinated Optimized Commit Protocol

RC-OCP: Reverse Coordinated Optimized Commit Protocol

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International Conference on Information systems and Computer Networks (ISCON)

作者： Chauhan, Ganpat Singh Gupta, Mukesh Kumar Khunteta, Ajay SKIT Comp Engn Jaipur Rajasthan India PCE Comp Engn Jaipur Rajasthan India

ISBN: (纸本)9781479929818

With the growth of trends in computing and requirement for developing a reliable computing environment the need for performing tasks in distributed manner has gained much importance. Atomic commit protocols (ACP) are used to preserve the ACID property in distributed systems. Two-Phase Commit (2PC) is most widely used but the blocking of sites is undesirable as these sites may be holding locks on the resources. As alternative, non-blocking ACP has been suggested: This non-blocking protocol is Three-Phase Commit (3PC) protocol which requires an extra phase (pre-commit) to remove blocking state. The existing protocols require so many messages transfer from the coordinator to participants and vice versa during different phases and corresponding increase communication and time complexity and hold the locks acquire by different participants till the end of last phase, forcing other transactions also to be blocked just because of the objects that are locked. All the existing protocols give the same performance for both deferred and immediate consistency constraints databases. Lots of protocols are being proposed and mainly the concentration was to make the 2PC protocol non-blocking or to minimize the blocking possibilities in 2PC. There has been a renewed interest in developing and optimization of more efficient ACPs. This paper is an effort to propose a new technique to optimize atomic commit protocols by optimizing voting phase based on deferred and immediate consistency constraints. Also an attempt has been made to propose reduction in communication complexity which will require less number of messages to be shared between coordinator and participants, the cost of execution as well as time delays.

关键词： distributed database system Two Phase Commit Protocol (2PC) Three Phase Commit Protocol (3PC) Non-Blocking Commit Protocol Deferred and Immediate consistency constraints

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IOCP: Implementation of Optimized Commit Protocol

IOCP: Implementation of Optimized Commit Protocol

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IEEE International Conference on Recent Advances and Innovations in Engineering (ICRAIE)

作者： Chauhan, Ganpat Singh Gupta, Mukesh Kumar Khunteta, Ajay PCE Comp Engn Jaipur Rajasthan India SKIT Comp Engn Jaipur Jaipur Rajasthan India

ISBN: (纸本)9781479940400

Atomic Commit Protocols (ACP) are used to maintain atomicity in distributed systems. There are protocols available to minimize the overhead between the coordinator and participants, some are to minimize blocking while some to release the locks acquire by different participants. Optimized Two phase Commit (O-2PC) Protocol has been proposed to optimize the performance of 2PC based of deferred and immediately consistency constraints by overlapping the voting phase where initiation of protocol is done from participant side. But no simulator is currently available. This paper Implementation of Optimized Commit Protocol (IOCP) is an effort to allow simulating the performance of O-2PC empirically to consider the indirect costs that is not possible to calculate analytically. The simulator is developed using Java Network Programming. This simulation tool also provides facility to compare different commit protocols based on some performance parameters.

关键词： distributed database system Two Phase Commit Protocol (2PC) Optimized Two Phase Commit Protocol (O-2PC) Three Phase Commit Protocol (3PC) Non-Blocking Commit Protocol Deferred and Immediate consistency constraints

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Concurrency Control in a system for distributed databases (SDD-1)

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ACM Transactions on database systems (TODS) 1980年第1期5卷 18-51页

作者： Bernstein, Philip A. Shipman, David W. Rothnie, James B. Center for Research in Computing Technology Aiken Computation Laboratory Harvard University Cambridge MA 02138 United States Computer Corporation of America 575 Technology Square Cambridge MA 02139 United States

This paper presents the concurrency control strategy of SDD-1. SDD-1, a system for distributed databases, is a prototype distributed database system being developed by Computer Corporation of America. In SDD-1, portions of data distributed throughout a network may be replicated at multiple sites. The SDD-1 concurrency control guarantees database consistency in the face of such distribution and replication. This paper is one of a series of companion papers on SDD-1 [4, 10, 12, 21]. © 1980, ACM. All rights reserved.

关键词： concurrency control conflict graph distributed database system serializability synchronization timestamps

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A Study of Blockchain-Based Metadata Management and Its Use for Data Verification 12

A Study of Blockchain-Based Metadata Management and Its Use ...

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12th International Symposium on Computing and Networking Workshops

作者： Hori, Haruka Oguchi, Masato Ochanomizu Univ Grad Sch Humanities & Sci Tokyo Japan Ochanomizu Univ Dept Informat Sci Tokyo Japan

ISBN: (纸本)9798331505356;9798331505349

To realize a data-driven society, it is essential to develop a distributed database system capable of managing data with varying levels of trust in a unified manner. In such a system, a robust data verification mechanism is crucial for ensuring the security of all data. However, there are concerns about performance degradation caused by the increased volume of data being verified at each node. To address this issue, we propose limiting the scope of data verification to metadata. In this paper, we implement a metadata management method that ensures reliability. This is achieved by integrating a series of processes related to metadata generation and updating as built-in commands within the Hyperledger Iroha blockchain platform. This integration also enables the implementation of a metadata verification function in a distributed database system. Additionally, using this metadata, we propose methods for both naive and simplified data verification.

关键词： distributed database system blockchain data validation distributed storage system

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A Comparison of Two database Partitioning Approaches that Support Taxonomy-Based Query Answering 22

A Comparison of Two Database Partitioning Approaches that Su...

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22nd Annual International Conference on Information Integration and Web-Based Applications and Services (IIWAS)

作者： Schaefer, Jero Mario Wiese, Lena Univ Gottingen Inst Comp Sci Gottingen Germany Goethe Univ Frankfurt Inst Comp Sci Frankfurt Germany

ISBN: (纸本)9781450389228

In this paper we address the topic of identification of cohorts of similar patients in a database of electronic health records. We follow the conjecture that retrieval of similar patients can be supported by an underlying distributed database design. Hence we propose a fragmentation based on partitioning the health records and present a benchmark of two implementation variants in comparison to an off-the-shelf data distribution approach provided by Apache Ignite. While our main use case in this paper is cohort identification, our approach has advantages for taxonomy-based query answering in other (non-medical) domains.

关键词： distributed database system relational databases taxonomy-based query answering

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Hierarchical simultaneous vertical fragmentation and allocation using modified Bond Energy Algorithm in distributed databases

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Applied Computing and Informatics 2018年第2期14卷 127-133页

作者： Rahimi, Hossein Parand, Fereshteh-Azadi Riahi, Davoud Math and Computer Science Department Allameh Tabataba'i University Ahmad Ghasir St. Beheshti Av. Tehran Iran

Designing an efficient distributed database system (DDBS) is considered as one of the most challenging problems because of multiple interdependent factors which are affecting its performance. Allocation and fragmentation are two processes which their efficiency and correctness influence the performance of DDBS. Therefore, efficient data fragmentation and allocation of fragments across the network sites are considered as an important research area in distributed database design. This paper presents an approach which simultaneously fragments data vertically and allocates the fragments to appropriate sites across the network. Bond Energy Algorithm (BEA) is applied with a better affinity measure that improves the generated clusters of attributes. The algorithm simultaneously generates clusters of attributes, calculates the cost of allocating each cluster to each site and allocates each cluster to the most appropriate site. Results show more efficient clustering and allocation which gives better performance. © 2015 The Authors

关键词： Bond Energy Algorithm Clustering Data allocation and fragmentation distributed database system

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distributed Machine Learning Scale Out with Algorithms and systems

Distributed Machine Learning Scale Out with Algorithms and S...

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作者： Yuan, Binhang Rice University

学位级别：Ph.D.

Machine learning (ML) is ubiquitous, and has powered the recent success of artificial intelligence. However, the state of affairs with respect to distributed ML is far from ideal. TensorFlow and PyTorch simply crash when an operation’s inputs and outputs cannot fit on a GPU for model parallelism, or when a model cannot fit on a single machine for data parallelism. A TensorFlow code that works reasonably well on a single machine with eight GPUs procured from a cloud provider often runs slower on two machines totaling sixteen GPUs. In this thesis, I propose solutions at both algorithm and system levels in order to scale out distributed ML. At the algorithm level, I propose a new method to distributed neural network learning, called independent subnet training (IST). In IST, per iteration, a neural network is decomposed into a set of subnetworks of the same depth as the original network, each of which is trained locally, before the various subnets are exchanged and the process is repeated. IST training has many advantages including reduction of communication volume and frequency, implicit extension to model parallelism, and memory limit decrease in each compute site. At the system level, I believe that proper computational and implementation abstractions will allow for the construction of self-configuring, declarative ML systems, especially when the goal is to execute tensor operations for ML in a distributed environment, or partitioned across multiple AI accelerators (ASICs). To this end, I first introduce a tensor relational algebra (TRA), which is expressive to encode any tensor operation that can be written in the Einstein notation, and then consider how TRA expressions can be re-written into an implementation algebra (IA) that enables effective implementation in a distributed environment, as well as how expressions in the IA can be optimized. The empirical study shows that the optimized implementation provided by IA can reach or even out-perform carefully engineer

关键词： distributed Machine Learning distributed database system

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