{"title":"A multi-threading model for distributed mobile objects and its realization in FarGo","authors":"Miki Abu, I. Ben-Shaul","doi":"10.1109/ICDSC.2001.918961","DOIUrl":"https://doi.org/10.1109/ICDSC.2001.918961","url":null,"abstract":"We present a novel multi-threading programming model for frameworks that combine distributed and mobile objects, and corresponding compile-time and runtime support that realize this model. Key contributions include an automatic thread partitioning scheme that provides the abstraction of logical distributed threads, while permitting arbitrary migration of components which contain parts of the distributed threads in themselves. The distributed mobile multi-threading model is transparent to the application programmer, who uses normal syntax to encode multi-threading applications, but can lower the overhead associated with the model by specifying the migratable components. The multi-threaded model was implemented in FarGo, a Java-based middleware for dynamically-relocatable distributed applications.","PeriodicalId":276188,"journal":{"name":"Proceedings 21st International Conference on Distributed Computing Systems","volume":"1B 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127723393","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}
{"title":"Combining generality and practicality in a conit-based continuous consistency model for wide-area replication","authors":"Haifeng Yu, Amin Vahdat","doi":"10.1109/ICDSC.2001.918973","DOIUrl":"https://doi.org/10.1109/ICDSC.2001.918973","url":null,"abstract":"Replication is a key approach to scaling wide-area applications. However, the overhead associated with large-scale replication quickly becomes prohibitive across wide-area networks. One effective approach to addressing this limitation is to allow applications to dynamically trade reduced consistency for increased performance and availability. Although extensive study has been performed on relaxed consistency models in traditional replicated databases, none of the models can simultaneously achieve the following two typically conflicting requirements imposed by wide-area applications: generality (capturing application-specific consistency semantics) and practicality (enabling efficient application-independent consistency protocols to be designed and providing natural ways to express application semantics). We propose a conit-based continuous consistency model designed to simultaneously achieve generality and practicality. Our conit theory provides generality, where application-specific consistency requirements are exported as conits. Practicality is achieved by using a simple, spanning set of metrics for conit consistency and by using a per-write weight specification. We demonstrate the generality of our model through representative wide-area applications and by showing that a number of existing models can be expressed as instances of our model. Our efficient, application-independent consistency protocols and prototype implementation verify its practicality.","PeriodicalId":276188,"journal":{"name":"Proceedings 21st International Conference on Distributed Computing Systems","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116146258","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}
G. Riley, M. Ammar, R. Fujimoto, Donghua Xu, K. Perumalla
{"title":"Distributed network simulations using the dynamic simulation backplane","authors":"G. Riley, M. Ammar, R. Fujimoto, Donghua Xu, K. Perumalla","doi":"10.1109/ICDSC.2001.918947","DOIUrl":"https://doi.org/10.1109/ICDSC.2001.918947","url":null,"abstract":"Presents an approach for creating distributed, component-based simulations of communication networks by interconnecting models of sub-networks drawn from different network simulation packages. This approach supports the rapid construction of simulations for large networks by reusing existing models and software, and fast execution using parallel discrete event simulation techniques. A dynamic simulation backplane is proposed that provides a common format and protocol for message exchange, and services for transmitting data and synchronizing heterogeneous network simulation engines. In order to achieve plug-and-play interoperability, the backplane uses existing network communication standards and dynamically negotiates among the participant simulators to define a minimal subset of required information that each simulator must supply, as well as other optional information. The backplane then automatically creates a message format that can be understood by all participating simulators and dynamically creates the content of each message by using callbacks to the simulation engines. We describe our approach to interoperability as well as an implementation of the backplane. We present results that demonstrate the proper operation of the backplane by distributing a network simulation between two different simulation packages, ns2 and GloMoSim. Performance results show that the overhead for the creation of the dynamic messages is minimal. Although this work is specific to network simulations, we believe our methodology and approach can be used to achieve interoperability in other distributed computing applications as well.","PeriodicalId":276188,"journal":{"name":"Proceedings 21st International Conference on Distributed Computing Systems","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126213102","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}
{"title":"An application-oriented approach for distributed system modeling and simulation","authors":"M. Nikolaidou, D. Anagnostopoulos","doi":"10.1109/ICDSC.2001.918945","DOIUrl":"https://doi.org/10.1109/ICDSC.2001.918945","url":null,"abstract":"Complexity of applications operating in a network environment has been considerably increased, since numerous architectural models, such as the client/server model and its extensions, have lately emerged. When dealing with distributed applications, network modeling is not so demanding and modeling solutions for widely used network components are already adopted by commercial tools. We introduce a modeling approach for distributed systems, putting the emphasis on distributed applications. This approach enables the analytical description of applications on the basis of predetermined, high-level operations (or actions) which can be customized to conform to specific architectural models. Operations are ultimately expressed in terms of primitive actions. Through this multi-layer decomposition scheme, in-depth analysis of application mechanisms is promoted. The modeling approach is oriented towards performance evaluation through simulation and a simulation tool has been constructed for this purpose. Modeling examples and a case study for a distributed database banking system are also presented.","PeriodicalId":276188,"journal":{"name":"Proceedings 21st International Conference on Distributed Computing Systems","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126007641","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}
{"title":"An application of parameter estimation to route discovery by on-demand routing protocols","authors":"J. Sucec, I. Marsic","doi":"10.1109/ICDSC.2001.918950","DOIUrl":"https://doi.org/10.1109/ICDSC.2001.918950","url":null,"abstract":"To discover a route to a peer node, an on-demand routing protocol may initiate a flood-search procedure known as route discovery. By selecting the correct query radius, the number of packet transmissions required for route discovery can be minimized. This paper presents methods to estimate the geographic radius (R/sub G/) and the number of currently active pairs of communicating nodes (P) in a mobile ad-hoc network. The methods are entirely distributed and incur little communication overhead. Network nodes can apply the estimated parameters to predict the probability mass function (PMF) of the route discovery hop distance. An accurate prediction of the PMF aids the selection of an appropriate query radius for the route discovery process. A computationally lightweight procedure to select an appropriate query radius, based only on an estimate of P, is also proposed. Simulation results show that this procedure facilitates a sensible tradeoff between the route request packet overhead and the route reply delay.","PeriodicalId":276188,"journal":{"name":"Proceedings 21st International Conference on Distributed Computing Systems","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126792469","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}
{"title":"Performance tuning of distributed applications with CoSMoS","authors":"Christoph Steigner, J. Wilke","doi":"10.1109/ICDSC.2001.918946","DOIUrl":"https://doi.org/10.1109/ICDSC.2001.918946","url":null,"abstract":"Performance monitoring of distributed software executing on workstation cluster systems is a complex task because of the multitude of factors that can affect performance in these environments. For performance analysis to be done effectively, all runtime events which have an impact on performance have to be captured. We introduce an integrated monitoring system that is capable of recording performance data on the application level, the operating system level, and the network level. It is thus able to provide complete coverage of all subsystems relevant to application performance. One of the key features of the proposed monitoring system is its ability to correlate performance data with application source code, pointing the developer to the portions of his code that may be time-critical. The system thus supports a cyclic process of optimizing performance in multiple iterations of analysis and refinement. This method allows performance bottlenecks to be tracked down to source code instruction level.","PeriodicalId":276188,"journal":{"name":"Proceedings 21st International Conference on Distributed Computing Systems","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127108202","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}
{"title":"Appia, a flexible protocol kernel supporting multiple coordinated channels","authors":"Hugo M. Miranda, A. Pinto, L. Rodrigues","doi":"10.1109/ICDSC.2001.919005","DOIUrl":"https://doi.org/10.1109/ICDSC.2001.919005","url":null,"abstract":"Distributed applications are becoming increasingly complex, often requiring the simultaneous use of several communication channels with different qualities-of-service. This paper presents the Appia system, a protocol kernel that supports applications requiring multiple coordinated channels. Appia offers a clean and elegant way for the application to express inter-channel constraints, such as, for instance, that all channels should provide consistent information about the failures of remote nodes. These constraints can be implemented as protocol layers that can be dynamically combined with other protocol layers.","PeriodicalId":276188,"journal":{"name":"Proceedings 21st International Conference on Distributed Computing Systems","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124763203","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}
{"title":"Generalized role-based access control","authors":"Matthew J. Moyer, M. Ahamad","doi":"10.1109/ICDSC.2001.918969","DOIUrl":"https://doi.org/10.1109/ICDSC.2001.918969","url":null,"abstract":"Generalized Role-Based Access Control (GRBAC) is a new paradigm for creating and maintaining rich access control policies. GRBAC leverages and extends the power of traditional role based access control (RBAC) by incorporating subject roles, object roles and environment roles into access control decisions. Subject roles are like traditional RBAC roles: they abstract the security-relevant characteristics of subjects into categories that can be used in defining a security policy. Similarly, object roles abstract the various properties of objects, such as object type (e.g., text, JPEG, executable) or sensitivity level (e.g., classified, top secret) into categories. Environment roles capture environmental information, such as time of day or system load so it can be used to mediate access control. Together, these three types of roles offer flexibility and expressive power, as well as a degree of usability not found in current access control models.","PeriodicalId":276188,"journal":{"name":"Proceedings 21st International Conference on Distributed Computing Systems","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116567659","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}
{"title":"Adaptive parameter collection in dynamic distributed environments","authors":"Zhenghua Fu, N. Venkatasubramanian","doi":"10.1109/ICDSC.2001.918977","DOIUrl":"https://doi.org/10.1109/ICDSC.2001.918977","url":null,"abstract":"Cost-effectively collecting distributed state information is a challenging problem. There is perhaps no single perfect solution since different distributed application environments pose different requirements from the information collection process. Knowledge of the environment, in terms of traffic conditions, load models etc., plays a key role in determining tradeoffs between accuracy (needed to ensure quality-of-service requirements) and cost-effectiveness. We develop an adaptive information collection algorithm that utilizes network traffic knowledge characterized using a time series model. The algorithm utilizes an information collection architecture consisting of a directory service integrated into the middleware layer with monitoring modules distributed across the network. The cost-effectiveness of the proposed information collection algorithm proposed is verified in simulations over diverse network traffic patterns, i.e. Internet WAN (TCP), MPEG (multimedia) and Web access traffic traces. Our results show that the proposed adaptive information collection algorithm compensates for inaccuracies in network traffic predictions in a cost-effective manner.","PeriodicalId":276188,"journal":{"name":"Proceedings 21st International Conference on Distributed Computing Systems","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132706147","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}
{"title":"Support for speculative update propagation and mobility in Deno","authors":"U. Çetintemel, P. Keleher, M. Franklin","doi":"10.1109/ICDSC.2001.918981","DOIUrl":"https://doi.org/10.1109/ICDSC.2001.918981","url":null,"abstract":"This paper presents the replication framework of Deno, an object replication system specifically designed for mobile and weakly-connected environments. Deno uses weighted voting for availability and pair-wise, epidemic information flow for flexibility. This combination allows the protocols to operate with less than full connectivity, to easily adapt to changes in group membership, and to make few assumptions about the underlying network topology. Deno has been implemented and runs on top of Linux and Win32 platforms. We use the Deno prototype to characterize the performance of two versions of Deno's protocol. The first version enables globally serializable execution of update transactions. The second supports a weaker consistency level that still guarantees transactionally-consistent access to replicated data. We demonstrate that the incremental cost of providing global serializability is low, and that speculative dissemination of updates can significantly improve commit performance.","PeriodicalId":276188,"journal":{"name":"Proceedings 21st International Conference on Distributed Computing Systems","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134164681","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}