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Full-Text Articles in Physical Sciences and Mathematics

P-Code: A New Raid-6 Code With Optimal Properties, Chao Jin, Hong Jiang, Dan Feng, Lei Tian Jun 2009

P-Code: A New Raid-6 Code With Optimal Properties, Chao Jin, Hong Jiang, Dan Feng, Lei Tian

CSE Conference and Workshop Papers

RAID-6 significantly outperforms the other RAID levels in disk-failure tolerance due to its ability to tolerate arbitrary two concurrent disk failures in a disk array. The underlying parity array codes have a significant impact on RAID-6’s performance. In this paper, we propose a new XOR-based RAID-6 code, called the Partition Code (P-Code). P-Code is a very simple and flexible vertical code, making it easy to understand and implement. It works on a group of (prime – 1) or (prime) disks, and its coding scheme is based on an equal partition of a specified two-integer-tuple set. P-Code has the following properties: …


Beyond Output Voting: Detecting Compromised Replicas Using Hmm-Based Behavioral Distance, Debin Gao, Michael K. Reiter, Dawn Song Apr 2009

Beyond Output Voting: Detecting Compromised Replicas Using Hmm-Based Behavioral Distance, Debin Gao, Michael K. Reiter, Dawn Song

Research Collection School Of Computing and Information Systems

Many host-based anomaly detection techniques have been proposed to detect code-injection attacks on servers. The vast majority, however, are susceptible to "mimicry" attacks in which the injected code masquerades as the original server software, including returning the correct service responses, while conducting its attack. "Behavioral distance," by which two diverse replicas processing the same inputs are continually monitored to detect divergence in their low-level (system-call) behaviors and hence potentially the compromise of one of them, has been proposed for detecting mimicry attacks. In this paper, we present a novel approach to behavioral distance measurement using a new type of hidden …


Jor: A Journal-Guided Reconstruction Optimization For Raid-Structured Storage Systems, Suzhen Wu, Dan Feng, Hong Jiang, Bo Mao, Lingfang Zeng, Jianxi Chen Jan 2009

Jor: A Journal-Guided Reconstruction Optimization For Raid-Structured Storage Systems, Suzhen Wu, Dan Feng, Hong Jiang, Bo Mao, Lingfang Zeng, Jianxi Chen

CSE Conference and Workshop Papers

This paper proposes a simple and practical RAID reconstruction optimization scheme, called JOurnal-guided Reconstruction (JOR). JOR exploits the fact that significant portions of data blocks in typical disk arrays are unused. JOR monitors the storage space utilization status at the block level to guide the reconstruction process so that only failed data on the used stripes is recovered to the spare disk. In JOR, data consistency is ensured by the requirement that all blocks in a disk array be initialized to zero (written with value zero) during synchronization while all blocks in the spare disk also be initialized to zero …


Dynamic Web Service Selection For Reliable Web Service Composition, San-Yih Hwang, Ee Peng Lim, Chien-Hsiang Lee, Cheng-Hung Chen Jan 2009

Dynamic Web Service Selection For Reliable Web Service Composition, San-Yih Hwang, Ee Peng Lim, Chien-Hsiang Lee, Cheng-Hung Chen

Research Collection School Of Computing and Information Systems

This paper studies the dynamic web service selection problem in a failure-prone environment, which aims to determine a subset of Web services to be invoked at run-time so as to successfully orchestrate a composite web service. We observe that both the composite and constituent web services often constrain the sequences of invoking their operations and therefore propose to use finite state machine to model the permitted invocation sequences of Web service operations. We assign each state of execution an aggregated reliability to measure the probability that the given state will lead to successful execution in the context where each web …