Failure models characterise the expected component failures in fault-tolerant computing. In the context of distributed systems, a failure model usually consists of two parts: a functional part specifying in what way individual processing entities may fail and a structural part specifying the potential scope of failures within the system. Such models must be expressive enough to cover all relevant practical situations, but must also be simple enough to allow uncomplicated reasoning about fault-tolerant algorithms. Usually, an increase in expressiveness complicates formal reasoning, but enables more accurate models that allow to improve the assumption coverage and resilience of solutions. In this paper, we introduce the structural failure model class DiDep that allows to specify directed dependent failures, which, for example, occur in the area of intrusion tolerance and security. DiDep is a generalisation of previous classes for undirected dependent failures, namely the general adversary structures, the fail-prone systems, and the core and survivor sets, which we show to be equivalent. We show that the increase in expressiveness of DiDep does not significantly penalise the simplicity of corresponding models by giving an algorithm that transforms any consensus algorithm for undirected dependent failures into a consensus algorithm for a DiDep model. We characterise the improved resilience obtained with DiDep and show that certain models even allow to circumvent the famous FLP impossibility result
{"title":"Solving Consensus Using Structural Failure Models","authors":"Timo Warns, F. Freiling, W. Hasselbring","doi":"10.1109/SRDS.2006.44","DOIUrl":"https://doi.org/10.1109/SRDS.2006.44","url":null,"abstract":"Failure models characterise the expected component failures in fault-tolerant computing. In the context of distributed systems, a failure model usually consists of two parts: a functional part specifying in what way individual processing entities may fail and a structural part specifying the potential scope of failures within the system. Such models must be expressive enough to cover all relevant practical situations, but must also be simple enough to allow uncomplicated reasoning about fault-tolerant algorithms. Usually, an increase in expressiveness complicates formal reasoning, but enables more accurate models that allow to improve the assumption coverage and resilience of solutions. In this paper, we introduce the structural failure model class DiDep that allows to specify directed dependent failures, which, for example, occur in the area of intrusion tolerance and security. DiDep is a generalisation of previous classes for undirected dependent failures, namely the general adversary structures, the fail-prone systems, and the core and survivor sets, which we show to be equivalent. We show that the increase in expressiveness of DiDep does not significantly penalise the simplicity of corresponding models by giving an algorithm that transforms any consensus algorithm for undirected dependent failures into a consensus algorithm for a DiDep model. We characterise the improved resilience obtained with DiDep and show that certain models even allow to circumvent the famous FLP impossibility result","PeriodicalId":164765,"journal":{"name":"2006 25th IEEE Symposium on Reliable Distributed Systems (SRDS'06)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131306635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Today's large-scale distributed systems consist of collections of nodes that have highly variable availability - a phenomenon sometimes called churn. This availability variation is often a hindrance to achieving reliability and performance for distributed applications such as multicast. This paper looks into utilizing and leveraging availability information in order to provide availability-dependent message reliability for multicast receivers. An application (e.g., a publish-sub scribe system) may want to scale the multicast message reliability at each receiver according to that receiver's availability (in terms of the fraction of time that receiver is online) ifferent options are that the reliability is independent of the availability, or proportional to it. We propose several gossip-based algorithms to support several such predicates. These techniques rely on each node's availability being monitored in a distributed manner by a small group of other nodes in such a way that the monitoring load is evenly distributed in the system. Our techniques are light-weight, scalable, and are space- and time-efficient. We analyze our algorithms and evaluate them experimentally by injecting availability traces collected from real peer-to-peer systems
{"title":"AVCast : New Approaches For Implementing Availability-Dependent Reliability for Multicast Receivers","authors":"Thadpong Pongthawornkamol, Indranil Gupta","doi":"10.1109/SRDS.2006.11","DOIUrl":"https://doi.org/10.1109/SRDS.2006.11","url":null,"abstract":"Today's large-scale distributed systems consist of collections of nodes that have highly variable availability - a phenomenon sometimes called churn. This availability variation is often a hindrance to achieving reliability and performance for distributed applications such as multicast. This paper looks into utilizing and leveraging availability information in order to provide availability-dependent message reliability for multicast receivers. An application (e.g., a publish-sub scribe system) may want to scale the multicast message reliability at each receiver according to that receiver's availability (in terms of the fraction of time that receiver is online) ifferent options are that the reliability is independent of the availability, or proportional to it. We propose several gossip-based algorithms to support several such predicates. These techniques rely on each node's availability being monitored in a distributed manner by a small group of other nodes in such a way that the monitoring load is evenly distributed in the system. Our techniques are light-weight, scalable, and are space- and time-efficient. We analyze our algorithms and evaluate them experimentally by injecting availability traces collected from real peer-to-peer systems","PeriodicalId":164765,"journal":{"name":"2006 25th IEEE Symposium on Reliable Distributed Systems (SRDS'06)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116056036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. D. Muñoz-Escoí, J. Pla-Civera, M. I. Ruiz-Fuertes, L. Irún-Briz, H. Decker, J. E. Armendáriz-Iñigo, J. R. G. D. Mendívil
Database replication protocols need to detect, block or abort part of conflicting transactions. A possible solution is to check their writesets (and also their readsets in case a serialisable isolation level is requested), which however burdens the consumption of CPU time. This gets even worse when the replication support is provided by a middleware, since there is no direct DBMS support in that layer. We propose and discuss the use of the concurrency control support of the local DBMS for detecting conflicts between local transactions and writesets of remote transactions. This allows to simplify many database replication protocols and to enhance their performance
{"title":"Managing Transaction Conflicts in Middleware-based Database Replication Architectures","authors":"F. D. Muñoz-Escoí, J. Pla-Civera, M. I. Ruiz-Fuertes, L. Irún-Briz, H. Decker, J. E. Armendáriz-Iñigo, J. R. G. D. Mendívil","doi":"10.1109/SRDS.2006.29","DOIUrl":"https://doi.org/10.1109/SRDS.2006.29","url":null,"abstract":"Database replication protocols need to detect, block or abort part of conflicting transactions. A possible solution is to check their writesets (and also their readsets in case a serialisable isolation level is requested), which however burdens the consumption of CPU time. This gets even worse when the replication support is provided by a middleware, since there is no direct DBMS support in that layer. We propose and discuss the use of the concurrency control support of the local DBMS for detecting conflicts between local transactions and writesets of remote transactions. This allows to simplify many database replication protocols and to enhance their performance","PeriodicalId":164765,"journal":{"name":"2006 25th IEEE Symposium on Reliable Distributed Systems (SRDS'06)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127831333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to safeguard a sensitive database, we must ensure both its privacy and its longevity. However, privacy and longevity tend to be competing objectives. We show how to design a system that provides both good privacy and good longevity simultaneously. Systems are modelled as compositions of two basic operators, copy and split. We propose metrics with which to evaluate the privacy, longevity and performance offered by such systems. The search for the "best" system under these metrics is then formulated as a constrained optimization problem. Solving the optimization problem exactly turns out to be intractable, so we propose techniques for efficiently finding an approximate solution
{"title":"How To Safeguard Your Sensitive Data","authors":"B. Mungamuru, H. Garcia-Molina, S. Mitra","doi":"10.1109/SRDS.2006.25","DOIUrl":"https://doi.org/10.1109/SRDS.2006.25","url":null,"abstract":"In order to safeguard a sensitive database, we must ensure both its privacy and its longevity. However, privacy and longevity tend to be competing objectives. We show how to design a system that provides both good privacy and good longevity simultaneously. Systems are modelled as compositions of two basic operators, copy and split. We propose metrics with which to evaluate the privacy, longevity and performance offered by such systems. The search for the \"best\" system under these metrics is then formulated as a constrained optimization problem. Solving the optimization problem exactly turns out to be intractable, so we propose techniques for efficiently finding an approximate solution","PeriodicalId":164765,"journal":{"name":"2006 25th IEEE Symposium on Reliable Distributed Systems (SRDS'06)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117081798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents two novel generic adaptive batching schemes for replicated servers. Both schemes are oblivious to the underlying communication protocols. Our novel schemes adapt their batching levels automatically and immediately according to the current communication load. This is done without any explicit monitoring or calibration of the system. Additionally, the paper includes a detailed performance evaluation
{"title":"Adaptive Batching for Replicated Servers","authors":"R. Friedman, Erez Hadad","doi":"10.1109/SRDS.2006.8","DOIUrl":"https://doi.org/10.1109/SRDS.2006.8","url":null,"abstract":"This paper presents two novel generic adaptive batching schemes for replicated servers. Both schemes are oblivious to the underlying communication protocols. Our novel schemes adapt their batching levels automatically and immediately according to the current communication load. This is done without any explicit monitoring or calibration of the system. Additionally, the paper includes a detailed performance evaluation","PeriodicalId":164765,"journal":{"name":"2006 25th IEEE Symposium on Reliable Distributed Systems (SRDS'06)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124464638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Denial of service (DoS) attacks attempt to consume a server's resources (network bandwidth, computing power, main memory, disk bandwidth etc.) to near exhaustion so that there are no resources left to handle requests from legitimate clients. An effective solution to defend against DoS attacks is to filter DoS attack requests at the earliest point (say, the Web site's firewall), before they consume much of the server's resources. Most defenses against DoS attacks attempt to filter requests from inauthentic clients before they consume much of the server's resources. Client authentication using techniques like IPSec or SSL may often require changes to the client-side software and may additionally require superuser privileges at the client for deployment. Further, using digital signatures (as in SSL) makes verification very expensive, thereby making the verification process itself a viable DoS target for the adversary. In this paper, we propose a light-weight client transparent technique to defend against DoS attacks with two unique features: (i) Our technique can be implemented entirely using JavaScript support provided by a standard client-side browser like Mozilla FireFox or Microsoft Internet Explorer. Client transparency follows from the fact that: (i) no changes to client-side software are required, (ii) no client-side superuser privileges are required, and (iii) clients (human beings or automated clients) can browse a DoS protected Web site in the same manner that they browse other Web sites, (ii) Although we operate using the client-side browser (HTTP layer), our technique enables fast IP level packet filtering at the server's firewall and requires no changes to the application(s) hosted by the Web server. In this paper we present a detailed design of our technique along with a detailed security analysis. We also describe a concrete implementation of our proposal on the Linux kernel and present an evaluation using two applications: bandwidth intensive Apache HTTPD and database intensive TPCW. Our experiments show that our approach incurs a low performance overhead and is resilient to DoS attacks
拒绝服务(DoS)攻击试图消耗服务器的资源(网络带宽、计算能力、主存、磁盘带宽等)，使其接近耗尽，从而没有资源来处理来自合法客户端的请求。防御DoS攻击的有效解决方案是在DoS攻击请求消耗大量服务器资源之前，在最早的点(例如，Web站点的防火墙)过滤它们。大多数针对DoS攻击的防御都试图在不真实的客户端消耗大量服务器资源之前过滤请求。使用IPSec或SSL等技术的客户端身份验证通常需要更改客户端软件，并且可能还需要客户端的超级用户权限才能进行部署。此外，使用数字签名(如SSL)使验证成本非常高，从而使验证过程本身成为攻击者可行的DoS目标。在本文中，我们提出了一种轻量级的客户端透明技术来防御DoS攻击，该技术具有两个独特的特性:(i)我们的技术可以完全使用标准客户端浏览器(如Mozilla FireFox或Microsoft Internet Explorer)提供的JavaScript支持来实现。客户透明度源于以下事实:(i)不需要更改客户端软件，(ii)不需要客户端超级用户权限，(iii)客户端(人类或自动客户端)可以像浏览其他网站一样浏览受DoS保护的网站，(ii)虽然我们使用客户端浏览器(HTTP层)操作，但我们的技术可以在服务器的防火墙中实现快速IP级数据包过滤，并且不需要更改Web服务器托管的应用程序。在本文中，我们给出了我们技术的详细设计以及详细的安全性分析。我们还描述了我们的建议在Linux内核上的具体实现，并使用两个应用程序进行了评估:带宽密集型Apache HTTPD和数据库密集型TPCW。我们的实验表明，我们的方法产生了较低的性能开销，并且对DoS攻击具有弹性
{"title":"A Client-Transparent Approach to Defend Against Denial of Service Attacks","authors":"M. Srivatsa, A. Iyengar, Jian Yin, Ling Liu","doi":"10.1109/SRDS.2006.6","DOIUrl":"https://doi.org/10.1109/SRDS.2006.6","url":null,"abstract":"Denial of service (DoS) attacks attempt to consume a server's resources (network bandwidth, computing power, main memory, disk bandwidth etc.) to near exhaustion so that there are no resources left to handle requests from legitimate clients. An effective solution to defend against DoS attacks is to filter DoS attack requests at the earliest point (say, the Web site's firewall), before they consume much of the server's resources. Most defenses against DoS attacks attempt to filter requests from inauthentic clients before they consume much of the server's resources. Client authentication using techniques like IPSec or SSL may often require changes to the client-side software and may additionally require superuser privileges at the client for deployment. Further, using digital signatures (as in SSL) makes verification very expensive, thereby making the verification process itself a viable DoS target for the adversary. In this paper, we propose a light-weight client transparent technique to defend against DoS attacks with two unique features: (i) Our technique can be implemented entirely using JavaScript support provided by a standard client-side browser like Mozilla FireFox or Microsoft Internet Explorer. Client transparency follows from the fact that: (i) no changes to client-side software are required, (ii) no client-side superuser privileges are required, and (iii) clients (human beings or automated clients) can browse a DoS protected Web site in the same manner that they browse other Web sites, (ii) Although we operate using the client-side browser (HTTP layer), our technique enables fast IP level packet filtering at the server's firewall and requires no changes to the application(s) hosted by the Web server. In this paper we present a detailed design of our technique along with a detailed security analysis. We also describe a concrete implementation of our proposal on the Linux kernel and present an evaluation using two applications: bandwidth intensive Apache HTTPD and database intensive TPCW. Our experiments show that our approach incurs a low performance overhead and is resilient to DoS attacks","PeriodicalId":164765,"journal":{"name":"2006 25th IEEE Symposium on Reliable Distributed Systems (SRDS'06)","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124967000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nowadays the great part of devices or systems we commonly use are often driven or managed by microchips and computers: cars, music players, phones, trains, planes, .... A consolidated trend of technology is to substitute mechanical with electronic parts, analogical with digital devices or controls, and so on. In this context, features like security, availability and reliability, usually summarized under the concept of dependability, are receiving higher attention. The dependability analysis, especially for what regards critical parts as computing systems or subsystems, is becoming more strategic: specific requirements and explicit or tighter constraints have to be satisfied. Even though this fact, there is a lack of suitable tools to properly model and analyze these aspects, with particular reference to reliability. To fill this gap, we propose the dynamic reliability block diagram (DRBD) modeling tool derived from the reliability block diagram (RBD) formalism. The DRBD permits to model the dynamic reliability behavior of a system through dependence models, exploited to represent dynamics behaviors as redundancy, load sharing, multiple, probabilistic and common failure mode. In this paper, the DRBD expressiveness and other capabilities, are illustrated through the analysis of a complex distributed computing system taken as example
{"title":"Modeling Distributed Computing System Reliability with DRBD","authors":"S. Distefano, M. Scarpa, A. Puliafito","doi":"10.1109/SRDS.2006.32","DOIUrl":"https://doi.org/10.1109/SRDS.2006.32","url":null,"abstract":"Nowadays the great part of devices or systems we commonly use are often driven or managed by microchips and computers: cars, music players, phones, trains, planes, .... A consolidated trend of technology is to substitute mechanical with electronic parts, analogical with digital devices or controls, and so on. In this context, features like security, availability and reliability, usually summarized under the concept of dependability, are receiving higher attention. The dependability analysis, especially for what regards critical parts as computing systems or subsystems, is becoming more strategic: specific requirements and explicit or tighter constraints have to be satisfied. Even though this fact, there is a lack of suitable tools to properly model and analyze these aspects, with particular reference to reliability. To fill this gap, we propose the dynamic reliability block diagram (DRBD) modeling tool derived from the reliability block diagram (RBD) formalism. The DRBD permits to model the dynamic reliability behavior of a system through dependence models, exploited to represent dynamics behaviors as redundancy, load sharing, multiple, probabilistic and common failure mode. In this paper, the DRBD expressiveness and other capabilities, are illustrated through the analysis of a complex distributed computing system taken as example","PeriodicalId":164765,"journal":{"name":"2006 25th IEEE Symposium on Reliable Distributed Systems (SRDS'06)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125243227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Network enabled capability (NEC) is the UK MoD's response to the rapidly changing conflict environment in which its forces must operate. The armed forces must be flexible, ready and rapidly deployable, and must possess attributes that allow the application of controlled and precise force to achieve realisable effects as part of a wider scene that includes diplomatic and political aspects. The implications of this operational goal are immense and will stimulate significant organisational changes throughout the entire defence supply chain, with knock-on effects in other industrial sectors and civilian environments. Recognising that achievement of NEC requires co-evolution across many different development areas and demands innovation throughout the supply chain, it is apparent that multidisciplinary research that includes a clear understanding of the integration issues is required. This may be attempted through development and application of systems engineering approaches to the delivery of through-life capability for NEC
{"title":"\"Open and challenging research issues in dependable distributed computing\" A personal view from the Defence Industry","authors":"J. Davies","doi":"10.1109/SRDS.2006.1","DOIUrl":"https://doi.org/10.1109/SRDS.2006.1","url":null,"abstract":"Network enabled capability (NEC) is the UK MoD's response to the rapidly changing conflict environment in which its forces must operate. The armed forces must be flexible, ready and rapidly deployable, and must possess attributes that allow the application of controlled and precise force to achieve realisable effects as part of a wider scene that includes diplomatic and political aspects. The implications of this operational goal are immense and will stimulate significant organisational changes throughout the entire defence supply chain, with knock-on effects in other industrial sectors and civilian environments. Recognising that achievement of NEC requires co-evolution across many different development areas and demands innovation throughout the supply chain, it is apparent that multidisciplinary research that includes a clear understanding of the integration issues is required. This may be attempted through development and application of systems engineering approaches to the delivery of through-life capability for NEC","PeriodicalId":164765,"journal":{"name":"2006 25th IEEE Symposium on Reliable Distributed Systems (SRDS'06)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129497097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hans P. Reiser, Jörg Domaschka, F. Hauck, R. Kapitza, Wolfgang Schröder-Preikschat
Determinism is mandatory for replicating distributed objects with strict consistency guarantees. Multithreaded execution of method invocations is a source of nondeterminism, but helps to improve performance and avoids deadlocks that nested invocations can cause in a single-threaded execution model. This paper contributes a novel algorithm for deterministic thread scheduling based on the interception of synchronisation statements. It assumes that shared data are protected by mutexes and client requests are sent to all replicas in total order; requests are executed concurrently as long as they do not issue potentially conflicting synchronisation operations. No additional communication is required for granting locks in a consistent order in all replicas. In addition to reentrant mutex locks, the algorithm supports condition variables and time-bounded wait operations. An experimental evaluation shows that, in some typical usage patterns of distributed objects, the algorithm is superior to other existing approaches
{"title":"Consistent Replication of Multithreaded Distributed Objects","authors":"Hans P. Reiser, Jörg Domaschka, F. Hauck, R. Kapitza, Wolfgang Schröder-Preikschat","doi":"10.1109/SRDS.2006.14","DOIUrl":"https://doi.org/10.1109/SRDS.2006.14","url":null,"abstract":"Determinism is mandatory for replicating distributed objects with strict consistency guarantees. Multithreaded execution of method invocations is a source of nondeterminism, but helps to improve performance and avoids deadlocks that nested invocations can cause in a single-threaded execution model. This paper contributes a novel algorithm for deterministic thread scheduling based on the interception of synchronisation statements. It assumes that shared data are protected by mutexes and client requests are sent to all replicas in total order; requests are executed concurrently as long as they do not issue potentially conflicting synchronisation operations. No additional communication is required for granting locks in a consistent order in all replicas. In addition to reentrant mutex locks, the algorithm supports condition variables and time-bounded wait operations. An experimental evaluation shows that, in some typical usage patterns of distributed objects, the algorithm is superior to other existing approaches","PeriodicalId":164765,"journal":{"name":"2006 25th IEEE Symposium on Reliable Distributed Systems (SRDS'06)","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131493168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Transactions are required not only for wired networks but also for the emerging wireless environments where mobile and fixed hosts participate side by side in the execution of the transaction. This heterogenous environment is characterized by constraints in mobile host capabilities, network connectivity and also an increasing number of possible failure modes. Classical atomic commit protocols used in wired networks are therefore not directly suitable for this heterogenous environment. Furthermore, the few commit protocols designed for mobile transactions either consider mobile hosts only as initiators though not as active participants, or show a high resource blocking time. We present the Fault-Tolerant Pre-Phase Transaction Commit (FT-PPTC) protocol for mobile environments. FT-PPTC decouples the commit of mobile participants from that of fixed participants. Consequently, the commit set can be reduced to a set of entities in the fixed network. Thus, the commit can easily be supported by any traditional atomic commit protocol, such as the established 2PC protocol. We integrate fault-tolerance as a key feature of FT-PPTC. Performance evaluations confirm the efficiency, scalability and low resource blocking time of our approach
{"title":"FT-PPTC: An Efficient and Fault-Tolerant Commit Protocol for Mobile Environments","authors":"Brahim Ayari, Abdelmajid Khelil, N. Suri","doi":"10.1109/SRDS.2006.22","DOIUrl":"https://doi.org/10.1109/SRDS.2006.22","url":null,"abstract":"Transactions are required not only for wired networks but also for the emerging wireless environments where mobile and fixed hosts participate side by side in the execution of the transaction. This heterogenous environment is characterized by constraints in mobile host capabilities, network connectivity and also an increasing number of possible failure modes. Classical atomic commit protocols used in wired networks are therefore not directly suitable for this heterogenous environment. Furthermore, the few commit protocols designed for mobile transactions either consider mobile hosts only as initiators though not as active participants, or show a high resource blocking time. We present the Fault-Tolerant Pre-Phase Transaction Commit (FT-PPTC) protocol for mobile environments. FT-PPTC decouples the commit of mobile participants from that of fixed participants. Consequently, the commit set can be reduced to a set of entities in the fixed network. Thus, the commit can easily be supported by any traditional atomic commit protocol, such as the established 2PC protocol. We integrate fault-tolerance as a key feature of FT-PPTC. Performance evaluations confirm the efficiency, scalability and low resource blocking time of our approach","PeriodicalId":164765,"journal":{"name":"2006 25th IEEE Symposium on Reliable Distributed Systems (SRDS'06)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127765433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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