Transoceanic video telephony (TVT) over the Internet is challenging due to 1) longer round-trip delay, 2) larger number of relay hops, and 3) higher packet loss rate. Real-world measurements of Skype, Face time, and QQ confirm that their TVT service quality is mostly unsatisfactory. Recently, when using We Chat to make transoceanic video calls, we are fortunate to find that it achieves stably smooth TVT. To explore how this is possible, we conduct in-depth measurements of We Chat data flow. In particular, we discover that the service provider of We Chat deploys a novel, specially designed "twin clouds" based architecture to deliver transoceanic (UDP) packets. Thus, data delivery between two callers is no longer point-to-point (used by Skype, Face time, and QQ) over the best-effort Internet. Instead, transoceanic video packets are delivered through the privileged backbone formed by twin clouds, which greatly reduces the round-trip delay, number of relay hops, and packet loss rate. Besides, whenever a packet is found lost, multiple duplicate packets are instantly sent to aggressively make up for the loss. On the other hand, we notice two-fold shortcomings of twin clouds. First, due to the sophisticated resource provisioning inside the twin clouds, the video start up time is considerably extended. Second, due to the high cost of deploying twin clouds, the capacity of the privileged backbone is limited and sometimes in shortage, and thus We Chat has to deliver data via a detour path with degraded performance. Ultimately, we believe that the twin clouds based data delivery solution will arouse a new direction of Internet video telephony research while still deserves optimization efforts.
{"title":"Do Twin Clouds Make Smoothness for Transoceanic Video Telephony?","authors":"Jian Li, Zhenhua Li, Yao Liu, Zhi-Li Zhang","doi":"10.1109/ICPP.2015.35","DOIUrl":"https://doi.org/10.1109/ICPP.2015.35","url":null,"abstract":"Transoceanic video telephony (TVT) over the Internet is challenging due to 1) longer round-trip delay, 2) larger number of relay hops, and 3) higher packet loss rate. Real-world measurements of Skype, Face time, and QQ confirm that their TVT service quality is mostly unsatisfactory. Recently, when using We Chat to make transoceanic video calls, we are fortunate to find that it achieves stably smooth TVT. To explore how this is possible, we conduct in-depth measurements of We Chat data flow. In particular, we discover that the service provider of We Chat deploys a novel, specially designed \"twin clouds\" based architecture to deliver transoceanic (UDP) packets. Thus, data delivery between two callers is no longer point-to-point (used by Skype, Face time, and QQ) over the best-effort Internet. Instead, transoceanic video packets are delivered through the privileged backbone formed by twin clouds, which greatly reduces the round-trip delay, number of relay hops, and packet loss rate. Besides, whenever a packet is found lost, multiple duplicate packets are instantly sent to aggressively make up for the loss. On the other hand, we notice two-fold shortcomings of twin clouds. First, due to the sophisticated resource provisioning inside the twin clouds, the video start up time is considerably extended. Second, due to the high cost of deploying twin clouds, the capacity of the privileged backbone is limited and sometimes in shortage, and thus We Chat has to deliver data via a detour path with degraded performance. Ultimately, we believe that the twin clouds based data delivery solution will arouse a new direction of Internet video telephony research while still deserves optimization efforts.","PeriodicalId":423007,"journal":{"name":"2015 44th International Conference on Parallel Processing","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128722771","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}
Song Wu, Chuxiong Yan, Haibao Chen, Hai Jin, Wenting Guo, Zhen Wang, Deqing Zou
For data centers with limited power supply, restricting the servers' power budget (i.e., The maximal power provided to servers) is an efficient approach to increase the server density (the server quantity per rack), which can effectively improve the cost-effectiveness of the data centers. However, this approach may also affect the performance of applications in servers. Hence, the prerequisite of adopting the approach in data centers is to precisely evaluate the application performance degradation caused by restricting the servers' power budget. Unfortunately, existing evaluation methods are inaccurate because they are either improper or coarse-grained, especially for the latency-sensitive applications widely deployed in data centers. In this paper, we analyze the reasons why state-of-the-art methods are not appropriate for evaluating the performance degradation of latency-sensitive applications in case of power restriction, and we propose a new evaluation method which can provide a fine-grained way to precisely describe and evaluate such degradation. We verify our proposed method by a real-world application and the traces from Ten cent's date enter with 25328 servers. The experimental results show that our method is much more accurate compared with the state of the art, and we can significantly increase datacenter efficiency by saving servers' power budget while maintaining the applications' performance degradation within controllable and acceptable range.
{"title":"Evaluating Latency-Sensitive Applications: Performance Degradation in Datacenters with Restricted Power Budget","authors":"Song Wu, Chuxiong Yan, Haibao Chen, Hai Jin, Wenting Guo, Zhen Wang, Deqing Zou","doi":"10.1109/ICPP.2015.73","DOIUrl":"https://doi.org/10.1109/ICPP.2015.73","url":null,"abstract":"For data centers with limited power supply, restricting the servers' power budget (i.e., The maximal power provided to servers) is an efficient approach to increase the server density (the server quantity per rack), which can effectively improve the cost-effectiveness of the data centers. However, this approach may also affect the performance of applications in servers. Hence, the prerequisite of adopting the approach in data centers is to precisely evaluate the application performance degradation caused by restricting the servers' power budget. Unfortunately, existing evaluation methods are inaccurate because they are either improper or coarse-grained, especially for the latency-sensitive applications widely deployed in data centers. In this paper, we analyze the reasons why state-of-the-art methods are not appropriate for evaluating the performance degradation of latency-sensitive applications in case of power restriction, and we propose a new evaluation method which can provide a fine-grained way to precisely describe and evaluate such degradation. We verify our proposed method by a real-world application and the traces from Ten cent's date enter with 25328 servers. The experimental results show that our method is much more accurate compared with the state of the art, and we can significantly increase datacenter efficiency by saving servers' power budget while maintaining the applications' performance degradation within controllable and acceptable range.","PeriodicalId":423007,"journal":{"name":"2015 44th International Conference on Parallel Processing","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116773758","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}
Feng Wang, Hao Jiang, Ke Zuo, Xing Su, Jingling Xue, Canqun Yang
This paper presents the design and implementation of a highly efficient Double-precision General Matrix Multiplication (DGEMM) based on Open BLAS for 64-bit ARMv8 eight-core processors. We adopt a theory-guided approach by first developing a performance model for this architecture and then using it to guide our exploration. The key enabler for a highly efficient DGEMM is a highly-optimized inner kernel GEBP developed in assembly language. We have obtained GEBP by (1) maximizing its compute-to-memory access ratios across all levels of the memory hierarchy in the ARMv8 architecture with its performance-critical block sizes being determined analytically, and (2) optimizing its computations through exploiting loop unrolling, instruction scheduling and software-implemented register rotation and taking advantage of A64 instructions to support efficient FMA operations, data transfers and prefetching. We have compared our DGEMM implemented in Open BLAS with another implemented in ATLAS (also in terms of a highly-optimized GEBP in assembly). Our implementation outperforms the one in ALTAS by improving the peak performance (efficiency) of DGEMM from 3.88 Gflops (80.9%) to 4.19 Gflops (87.2%) on one core and from 30.4 Gflops (79.2%) to 32.7 Gflops (85.3%) on eight cores. These results translate into substantial performance (efficiency) improvements by 7.79% on one core and 7.70% on eight cores. In addition, the efficiency of our implementation on one core is very close to the theoretical upper bound 91.5% obtained from micro-benchmarking. Our parallel implementation achieves good performance and scalability under varying thread counts across a range of matrix sizes evaluated.
{"title":"Design and Implementation of a Highly Efficient DGEMM for 64-Bit ARMv8 Multi-core Processors","authors":"Feng Wang, Hao Jiang, Ke Zuo, Xing Su, Jingling Xue, Canqun Yang","doi":"10.1109/ICPP.2015.29","DOIUrl":"https://doi.org/10.1109/ICPP.2015.29","url":null,"abstract":"This paper presents the design and implementation of a highly efficient Double-precision General Matrix Multiplication (DGEMM) based on Open BLAS for 64-bit ARMv8 eight-core processors. We adopt a theory-guided approach by first developing a performance model for this architecture and then using it to guide our exploration. The key enabler for a highly efficient DGEMM is a highly-optimized inner kernel GEBP developed in assembly language. We have obtained GEBP by (1) maximizing its compute-to-memory access ratios across all levels of the memory hierarchy in the ARMv8 architecture with its performance-critical block sizes being determined analytically, and (2) optimizing its computations through exploiting loop unrolling, instruction scheduling and software-implemented register rotation and taking advantage of A64 instructions to support efficient FMA operations, data transfers and prefetching. We have compared our DGEMM implemented in Open BLAS with another implemented in ATLAS (also in terms of a highly-optimized GEBP in assembly). Our implementation outperforms the one in ALTAS by improving the peak performance (efficiency) of DGEMM from 3.88 Gflops (80.9%) to 4.19 Gflops (87.2%) on one core and from 30.4 Gflops (79.2%) to 32.7 Gflops (85.3%) on eight cores. These results translate into substantial performance (efficiency) improvements by 7.79% on one core and 7.70% on eight cores. In addition, the efficiency of our implementation on one core is very close to the theoretical upper bound 91.5% obtained from micro-benchmarking. Our parallel implementation achieves good performance and scalability under varying thread counts across a range of matrix sizes evaluated.","PeriodicalId":423007,"journal":{"name":"2015 44th International Conference on Parallel Processing","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114575252","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}
Many data center applications have deadline requirements, which pose a requirement of deadline-awareness in network transport. Completing within deadlines is a necessary requirement for flows to be completed. Transport protocols in current data centers try to share the network resources fairly and are deadline-agnostic. Recently several works try to address the problem by making as many flows meet deadlines as possible. However, for many data center applications, a task cannot be completed until the last flow finishes, which indicates the bandwidths consumed by completed flows are wasted if some flows in the task cannot meet deadlines. In this paper we design a task-level deadline-aware preemptive flow scheduling(TAPS), which aims to make more tasks meet deadlines. We leverage software defined networking (SDN) technology and generalize SDN from flow-level awareness to task-level awareness. The scheduling algorithm runs on the SDN controller, which decides whether a flow should be accepted or discarded, pre-allocates the transmission time slices and computes the routing paths for accepted flows. Extensive flow-level simulations demonstrate TAPS outperforms Varys, Bara at, PDQ (Preemptive Distributed Quick flow scheduling), D3 (Deadline-Driven Delivery control protocol) and Fair Sharing transport protocols in deadline sensitive data center environment. A simple implementation on real systems also proves that TAPS makes high effective utilization of the network bandwidth in data centers.
{"title":"TAPS: Software Defined Task-Level Deadline-Aware Preemptive Flow Scheduling in Data Centers","authors":"Lili Liu, Dan Li, Jianping Wu","doi":"10.1109/ICPP.2015.75","DOIUrl":"https://doi.org/10.1109/ICPP.2015.75","url":null,"abstract":"Many data center applications have deadline requirements, which pose a requirement of deadline-awareness in network transport. Completing within deadlines is a necessary requirement for flows to be completed. Transport protocols in current data centers try to share the network resources fairly and are deadline-agnostic. Recently several works try to address the problem by making as many flows meet deadlines as possible. However, for many data center applications, a task cannot be completed until the last flow finishes, which indicates the bandwidths consumed by completed flows are wasted if some flows in the task cannot meet deadlines. In this paper we design a task-level deadline-aware preemptive flow scheduling(TAPS), which aims to make more tasks meet deadlines. We leverage software defined networking (SDN) technology and generalize SDN from flow-level awareness to task-level awareness. The scheduling algorithm runs on the SDN controller, which decides whether a flow should be accepted or discarded, pre-allocates the transmission time slices and computes the routing paths for accepted flows. Extensive flow-level simulations demonstrate TAPS outperforms Varys, Bara at, PDQ (Preemptive Distributed Quick flow scheduling), D3 (Deadline-Driven Delivery control protocol) and Fair Sharing transport protocols in deadline sensitive data center environment. A simple implementation on real systems also proves that TAPS makes high effective utilization of the network bandwidth in data centers.","PeriodicalId":423007,"journal":{"name":"2015 44th International Conference on Parallel Processing","volume":"147 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114642562","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}
Jonathan Lejeune, L. Arantes, Julien Sopena, Pierre Sens
Generalized distributed mutual exclusion algorithms allow processes to concurrently access a set of shared resources. However, they must ensure an exclusive access to each resource. In order to avoid deadlocks, many of them are based on the strong assumption of a prior knowledge about conflicts between processes' requests. Some other approaches, which do not require such a knowledge, exploit broadcast mechanisms or a global lock, degrading message complexity and synchronization cost. We propose in this paper a new solution for shared resources allocation which reduces the communication between non-conflicting processes without a prior knowledge of processes conflicts. Performance evaluation results show that our solution improves resource use rate by a factor up to 20 compared to a global lock based algorithm.
{"title":"Reducing Synchronization Cost in Distributed Multi-resource Allocation Problem","authors":"Jonathan Lejeune, L. Arantes, Julien Sopena, Pierre Sens","doi":"10.1109/ICPP.2015.63","DOIUrl":"https://doi.org/10.1109/ICPP.2015.63","url":null,"abstract":"Generalized distributed mutual exclusion algorithms allow processes to concurrently access a set of shared resources. However, they must ensure an exclusive access to each resource. In order to avoid deadlocks, many of them are based on the strong assumption of a prior knowledge about conflicts between processes' requests. Some other approaches, which do not require such a knowledge, exploit broadcast mechanisms or a global lock, degrading message complexity and synchronization cost. We propose in this paper a new solution for shared resources allocation which reduces the communication between non-conflicting processes without a prior knowledge of processes conflicts. Performance evaluation results show that our solution improves resource use rate by a factor up to 20 compared to a global lock based algorithm.","PeriodicalId":423007,"journal":{"name":"2015 44th International Conference on Parallel Processing","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114723792","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}
Haisheng Yu, Keqiu Li, Heng Qi, Wenxin Li, Xiaoyi Tao
Traditional networks are surprisingly fragile and difficult to manage. Software Defined Networking (SDN) gained significant attention from both academia and industry, as if simplify network management through centralized configuration. Existing work primarily focuses on networks of limited scope such as data-centers and enterprises, which makes the development of SDN hindered when it comes to large-scale network environments. One way of enabling communication between data-centers, enterprises and ISPs in a large-scale network is to establish a standard communication mechanism between these entities. In this paper, we propose Zebra, a framework for enabling communication between different SDN domains. Zebra has two modules: Heterogeneous Controller Management (HCM) module and Domain Relationships Management (DRM) module. HCM collects network information from a group of controllers with no interconnection and generate a domain-wide network view. DRM collects network information from other domains to generate a global-wide network view. Moreover, HCM supports different SDN controllers, such as floodlight, maestro and so on. To test this framework, we develop a prototype system, and give some experimental results.
{"title":"Zebra: An East-West Control Framework for SDN Controllers","authors":"Haisheng Yu, Keqiu Li, Heng Qi, Wenxin Li, Xiaoyi Tao","doi":"10.1109/ICPP.2015.70","DOIUrl":"https://doi.org/10.1109/ICPP.2015.70","url":null,"abstract":"Traditional networks are surprisingly fragile and difficult to manage. Software Defined Networking (SDN) gained significant attention from both academia and industry, as if simplify network management through centralized configuration. Existing work primarily focuses on networks of limited scope such as data-centers and enterprises, which makes the development of SDN hindered when it comes to large-scale network environments. One way of enabling communication between data-centers, enterprises and ISPs in a large-scale network is to establish a standard communication mechanism between these entities. In this paper, we propose Zebra, a framework for enabling communication between different SDN domains. Zebra has two modules: Heterogeneous Controller Management (HCM) module and Domain Relationships Management (DRM) module. HCM collects network information from a group of controllers with no interconnection and generate a domain-wide network view. DRM collects network information from other domains to generate a global-wide network view. Moreover, HCM supports different SDN controllers, such as floodlight, maestro and so on. To test this framework, we develop a prototype system, and give some experimental results.","PeriodicalId":423007,"journal":{"name":"2015 44th International Conference on Parallel Processing","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130378489","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}
Existing Data Center Network (DCN) architectures are classified into two categories: switch-centric and server-centric architectures. In switch-centric DCNs, routing intelligence is placed on switches, each server usually uses only one port of the Network Interface Card (NIC) to connect to the network. In server-centric DCNs, switches are only used as cross-bars, and routing intelligence is placed on servers, where multiple NIC ports may be used. In this paper, we formally introduce a new category of DCN architectures: the dual-centric DCN architectures, where routing intelligence can be placed on both switches and servers. We propose two typical dual-centric DCN architectures: FSquare and Rectangle, both of which are based on the folded Clos topology. FSquare is a high performance DCN architecture, in which the diameter is small and the bisection bandwidth is large, however, the DCN power consumption per server in FSquare is high. Rectangle significantly reduces the DCN power consumption per server, compared to FSquare, at the sacrifice of some performances, thus, Rectangle has a larger diameter and a smaller bisection bandwidth. By investigating FSquare and Rectangle, and by comparing them with existing architectures, we demonstrate that, these two novel dual-centric architectures enjoy the advantages of both switch-centric designs and server-centric designs, have various nice properties for practical data centers, and provide flexible choices in designing DCN architectures.
{"title":"Dual-centric Data Center Network Architectures","authors":"Dawei Li, Jie Wu, Zhiyong Liu, Fa Zhang","doi":"10.1109/ICPP.2015.77","DOIUrl":"https://doi.org/10.1109/ICPP.2015.77","url":null,"abstract":"Existing Data Center Network (DCN) architectures are classified into two categories: switch-centric and server-centric architectures. In switch-centric DCNs, routing intelligence is placed on switches, each server usually uses only one port of the Network Interface Card (NIC) to connect to the network. In server-centric DCNs, switches are only used as cross-bars, and routing intelligence is placed on servers, where multiple NIC ports may be used. In this paper, we formally introduce a new category of DCN architectures: the dual-centric DCN architectures, where routing intelligence can be placed on both switches and servers. We propose two typical dual-centric DCN architectures: FSquare and Rectangle, both of which are based on the folded Clos topology. FSquare is a high performance DCN architecture, in which the diameter is small and the bisection bandwidth is large, however, the DCN power consumption per server in FSquare is high. Rectangle significantly reduces the DCN power consumption per server, compared to FSquare, at the sacrifice of some performances, thus, Rectangle has a larger diameter and a smaller bisection bandwidth. By investigating FSquare and Rectangle, and by comparing them with existing architectures, we demonstrate that, these two novel dual-centric architectures enjoy the advantages of both switch-centric designs and server-centric designs, have various nice properties for practical data centers, and provide flexible choices in designing DCN architectures.","PeriodicalId":423007,"journal":{"name":"2015 44th International Conference on Parallel Processing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130614283","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}
Shanfeng Zhang, Q. Ma, Tong Zhu, Kebin Liu, Lan Zhang, Wenbo He, Yunhao Liu
Crowdsensing applications require individuals toshare local and personal sensing data with others to produce valuableknowledge and services. Meanwhile, it has raised concernsespecially for location privacy. Users may wish to prevent privacyleak and publish as many non-sensitive contexts as possible.Simply suppressing sensitive contexts is vulnerable to the adversariesexploiting spatio-temporal correlations in users' behavior.In this work, we present PLP, a crowdsensing scheme whichpreserves privacy while maximizes the amount of data collectionby filtering a user's context stream. PLP leverages a conditionalrandom field to model the spatio-temporal correlations amongthe contexts, and proposes a speed-up algorithm to learn theweaknesses in the correlations. Even if the adversaries are strongenough to know the filtering system and the weaknesses, PLPcan still provably preserves privacy, with little computationalcost for online operations. PLP is evaluated and validated overtwo real-world smartphone context traces of 34 users. Theexperimental results show that PLP efficiently protects privacywithout sacrificing much utility.
{"title":"PLP: Protecting Location Privacy Against Correlation-Analysis Attack in Crowdsensing","authors":"Shanfeng Zhang, Q. Ma, Tong Zhu, Kebin Liu, Lan Zhang, Wenbo He, Yunhao Liu","doi":"10.1109/ICPP.2015.20","DOIUrl":"https://doi.org/10.1109/ICPP.2015.20","url":null,"abstract":"Crowdsensing applications require individuals toshare local and personal sensing data with others to produce valuableknowledge and services. Meanwhile, it has raised concernsespecially for location privacy. Users may wish to prevent privacyleak and publish as many non-sensitive contexts as possible.Simply suppressing sensitive contexts is vulnerable to the adversariesexploiting spatio-temporal correlations in users' behavior.In this work, we present PLP, a crowdsensing scheme whichpreserves privacy while maximizes the amount of data collectionby filtering a user's context stream. PLP leverages a conditionalrandom field to model the spatio-temporal correlations amongthe contexts, and proposes a speed-up algorithm to learn theweaknesses in the correlations. Even if the adversaries are strongenough to know the filtering system and the weaknesses, PLPcan still provably preserves privacy, with little computationalcost for online operations. PLP is evaluated and validated overtwo real-world smartphone context traces of 34 users. Theexperimental results show that PLP efficiently protects privacywithout sacrificing much utility.","PeriodicalId":423007,"journal":{"name":"2015 44th International Conference on Parallel Processing","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124725160","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}
Ming Zhu, Dan Li, Y. Liu, Dan Pei, K. Ramakrishnan, Lili Liu, Jianping Wu
Today's interdomain routing is traffic agnostic when determining the single, best forwarding path. Naturally, as it does not adapt to congestion, the path chosen is not always optimal. In this paper, we focus on designing a multi-path interdomain forwarding (MIFO) mechanism, where AS border routers adaptively forward outbound traffic from a congested default path to an alternative path, without touching the interdomain routing protocols. Different from previous efforts which enable multi-path on control plane, MIFO achieves multi-path on data plane. The multiple alternative forwarding paths are obtained by exploring local BGP RIB. Multi-path forwarding on data plane can create a loop even within a stable network. MIFO solves this problem with a simple and practical approach. Several other challenges are also addressed including preventing cycling packet between iBGP peers and choosing the best alternative path from among multiple candidates. Our evaluations show that MIFO significantly improves the end-to-end throughput at the AS level, compared to traditional BGP and MIRO. For example, with only 50% of the ASes being MIFO capable, a significant percentage of the flows (about 40%) can use at least 50% of the inter-AS link capacity. In contrast, BGP and MIRO routing make less effective use of the inter-AS links, with only 7% and 17% of the flows can be so. Finally, we have developed a prototype implementation of MIFO on Linux with the forwarding engine in the kernel, with the routing daemon developed on XORP platform. The experiments on a test bed built with prototypes show that MIFO can improves the aggregate throughput by 81% compared with BGP routing.
{"title":"MIFO: Multi-path Interdomain Forwarding","authors":"Ming Zhu, Dan Li, Y. Liu, Dan Pei, K. Ramakrishnan, Lili Liu, Jianping Wu","doi":"10.1109/ICPP.2015.27","DOIUrl":"https://doi.org/10.1109/ICPP.2015.27","url":null,"abstract":"Today's interdomain routing is traffic agnostic when determining the single, best forwarding path. Naturally, as it does not adapt to congestion, the path chosen is not always optimal. In this paper, we focus on designing a multi-path interdomain forwarding (MIFO) mechanism, where AS border routers adaptively forward outbound traffic from a congested default path to an alternative path, without touching the interdomain routing protocols. Different from previous efforts which enable multi-path on control plane, MIFO achieves multi-path on data plane. The multiple alternative forwarding paths are obtained by exploring local BGP RIB. Multi-path forwarding on data plane can create a loop even within a stable network. MIFO solves this problem with a simple and practical approach. Several other challenges are also addressed including preventing cycling packet between iBGP peers and choosing the best alternative path from among multiple candidates. Our evaluations show that MIFO significantly improves the end-to-end throughput at the AS level, compared to traditional BGP and MIRO. For example, with only 50% of the ASes being MIFO capable, a significant percentage of the flows (about 40%) can use at least 50% of the inter-AS link capacity. In contrast, BGP and MIRO routing make less effective use of the inter-AS links, with only 7% and 17% of the flows can be so. Finally, we have developed a prototype implementation of MIFO on Linux with the forwarding engine in the kernel, with the routing daemon developed on XORP platform. The experiments on a test bed built with prototypes show that MIFO can improves the aggregate throughput by 81% compared with BGP routing.","PeriodicalId":423007,"journal":{"name":"2015 44th International Conference on Parallel Processing","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123190059","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}
To put mobile sensing into large-scale deployments, we have to take care of sensing participants' incentives and privacy first. In this paper, we study how to protect the sensing participants' privacy in the mobile sensing market where multiple sensing jobs reside in one consolidated place. Our problem is highly challenging due to the facts that incentives are introduced and we consider both the sensing job owner and the market administrator could invade the sensing participants' privacy. We propose two privacy-preserving market mechanisms that are able to protect the sensing participants' privacy to solve our problem. Experiments also demonstrate that our mechanisms have good efficiency.
{"title":"Privacy Preserving Market Schemes for Mobile Sensing","authors":"Yuan Zhang, Yunlong Mao, He Zhang, Sheng Zhong","doi":"10.1109/ICPP.2015.100","DOIUrl":"https://doi.org/10.1109/ICPP.2015.100","url":null,"abstract":"To put mobile sensing into large-scale deployments, we have to take care of sensing participants' incentives and privacy first. In this paper, we study how to protect the sensing participants' privacy in the mobile sensing market where multiple sensing jobs reside in one consolidated place. Our problem is highly challenging due to the facts that incentives are introduced and we consider both the sensing job owner and the market administrator could invade the sensing participants' privacy. We propose two privacy-preserving market mechanisms that are able to protect the sensing participants' privacy to solve our problem. Experiments also demonstrate that our mechanisms have good efficiency.","PeriodicalId":423007,"journal":{"name":"2015 44th International Conference on Parallel Processing","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124482560","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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