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Towards a two-tier internet coordinate system to mitigate the impact of triangle inequality violations
- In Proc. IFIP Networking Conference, LNCS 4982
, 2008
"... Abstract. Routing policies or path inflation can give rise to violations of the Triangle Inequality with respect to delay (RTTs) in the Internet. In network co-ordinate systems, such Triangle Inequality Violations (TIVs) will introduce in-accuracy, as nodes in this particular case could not be embed ..."
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Cited by 6 (6 self)
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Abstract. Routing policies or path inflation can give rise to violations of the Triangle Inequality with respect to delay (RTTs) in the Internet. In network co-ordinate systems, such Triangle Inequality Violations (TIVs) will introduce in-accuracy, as nodes in this particular case could not be embedded into any metric space. In this paper, we consider these TIVs as an inherent and natural property of the Internet; rather than trying to remove them, we consider characterizing them and mitigating their impact on distributed coordinate systems. In a first step, we study TIVs existing in the Internet, using different metrics in order to quantify various levels of TIVs ’ severity. Our results show that path lengths do have an effect on the impact of these TIVs. In particular, the shorter the link between any two nodes is, the less severe TIVs involved in are. In a second step, we do leverage our study to reduce the impact of TIVs on coor-dinate systems. We focus on the particular case of the Vivaldi coordinate system and we explore how TIVs may impact its accuracy and stability. In particular, we observed correlation between the (in)stability and high effective error of nodes’ coordinates with respect to their involvement in TIVs situations. We finally pro-pose a Two-Tier architecture opposed to a flat structure of Vivaldi that do mitigate the effect of TIVs on the distances predictions.
Routing Performance in a Hierarchical DHT-based Overlay Network
- Parallel, Distributed, and Network-Based Processing, Euromicro Conference on, Los Alamitos
"... The scalability properties of DHT based overlay net-works is considered satisfactory. However, in large scale systems this might still cause a problem since they have a logarithmic complexity depending. Further, they only provide a one dimensional structure and do not make use on inherent clustering ..."
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Cited by 5 (3 self)
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The scalability properties of DHT based overlay net-works is considered satisfactory. However, in large scale systems this might still cause a problem since they have a logarithmic complexity depending. Further, they only provide a one dimensional structure and do not make use on inherent clustering properties of some applications (e.g. P2PVoIP or locality aware overlays). Thus, structures based on a hierarchical approach can have performance as well as structural advantages. In this paper, a generic hierarchical architecture based on super-peers is presented where a peer ID is composed by a Prefix ID and a Suffix ID. Prefix ID is only routed at the super-peer level and the Suffix ID at the peer level. We specifically analyse the Rout-ing Performance of this approach within the context of two specific overlays, viz. CAN and Kademlia. 1
Enabling global multimedia distributed services based on hierarchical DHT overlay networks
- in: Proceedings of the Second International Conference on Next Generation Mobile Applications, Services and Technologies, NGMAST ’08
, 2008
"... The provision of innovating multimedia services is a high priority for service providers. Due to the the high traffic volume characteristics of multimedia content, decentralised services are a desired solution for multimedia scenarios. Based on the ongoing work of the IETF P2PSIP WG this paper defin ..."
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Cited by 2 (1 self)
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The provision of innovating multimedia services is a high priority for service providers. Due to the the high traffic volume characteristics of multimedia content, decentralised services are a desired solution for multimedia scenarios. Based on the ongoing work of the IETF P2PSIP WG this paper defines a simple way to interconnect different do-mains using on peer-to-peer technology. The objective is to provide connectivity between users of different domains and allow decentralised multimedia services to be placed where they can be provided most effectively. Furthermore, the routing performance and routing state is analysed for the proposed hierarchical DHT overlay architecture. 1.
AVMEM- Availability-Aware Overlays for Management Operations in Non-cooperative Distributed Systems ⋆
"... Abstract. Monitoring and management operations that query nodes based on their availability can be extremely useful in a variety of largescale distributed systems containing hundreds to thousands of hosts, e.g., p2p systems, Grids, and PlanetLab. This paper presents decentralized and scalable soluti ..."
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Cited by 2 (2 self)
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Abstract. Monitoring and management operations that query nodes based on their availability can be extremely useful in a variety of largescale distributed systems containing hundreds to thousands of hosts, e.g., p2p systems, Grids, and PlanetLab. This paper presents decentralized and scalable solutions to a subset of such availability-based management tasks. Specifically, we propose AVMEM, which is the first availabilityaware overlay to date. AVMEM is intended for generic non-cooperative scenarios where nodes may be selfish and may wish to route messages to a large set of other nodes, especially if the selfish node has low availability. Under this setting, our concrete contributions are the following: (1) AVMEM allows arbitrary classes of application-specified predicates to create the membership relationships in the overlay. In order to avoid selfish nodes from exploiting the system, we focus on predicates that are random and consistent. In other words, whether a given node y is a neighbor of a given node x is decided based on a consistent and probabilistic predicate, dependent solely on the identifiers and availabilities of these two nodes, but without using any external inputs. (2) AVMEM protocols discover and maintain the overlay spanned by the application-specified AVMEM predicate in a scalable and fast manner. (3) We use AVMEM to execute important availability-based management operations, focusing on range-anycast, range-multicast, threshold-anycast, and thresholdmulticast. AVMEM works well in the presence of selfish nodes, scales to thousands of nodes, and executes each of the targeted operations quickly and reliably. Our evaluation is driven by real-life churn traces from the Overnet p2p system, and shows that AVMEM works well in practical settings.
DESIGN OF AVAILABILITY-DEPENDENT DISTRIBUTED SERVICES IN LARGE-SCALE UNCOOPERATIVE SETTINGS
, 2009
"... Availability-dependent global predicates can be efficiently and scalably realized for a class of distributed services, in spite of specific selfish and colluding behaviors, using local and decentralized protocols. Several types of large-scale distributed systems spanning the Internet have to deal wi ..."
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Availability-dependent global predicates can be efficiently and scalably realized for a class of distributed services, in spite of specific selfish and colluding behaviors, using local and decentralized protocols. Several types of large-scale distributed systems spanning the Internet have to deal with availability variations among their constituent nodes. In dealing with churn and low availability nodes, we believe it is important to link the availability of a node to the service the node receives from the distributed system. In other words, high availability has to be incentivized with better service. There are two types of requirements for this problem. First, metrics such as message overhead, CPU usage, memory overhead and latency need to be optimized to achieve scalability and efficiency. Secondly, in open distributed systems spanning multiple organizations, the protocols have to tolerate selfish and colluding nodes, i.e., low availability nodes that attempt to receive better service. This thesis approaches this problem by explicitly linking each node’s service to its availability, via the notion of a global predicate. We present a class of novel distributed protocols that achieve a given availability-dependent global predicate, efficiently and scalably. These protocols execute in a
Benefits of an Implementation of H-P2PSIP
"... Abstract—In this paper, we report on the results of experiments with an implementation of H-P2PSIP, which allows the exchange of information among different DHTs (Distributed Hash Tables) making use of a hierarchical architecture. This paper validates our previous H-P2PSIP proposal in an environment ..."
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Abstract—In this paper, we report on the results of experiments with an implementation of H-P2PSIP, which allows the exchange of information among different DHTs (Distributed Hash Tables) making use of a hierarchical architecture. This paper validates our previous H-P2PSIP proposal in an environment with a real TCP/IP stack close to a real scenario. The results show how the benefits of this real H-P2PSIP implementation in terms of routing performance (number of hops), delay and routing state (number of routing entries) are better than a flat DHT overlay network and how the exchange of information among different DHT overlay networks is feasible.
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"... Abstract: Providing innovating multimedia services is a high priority for service providers. Due to the high traffic volume created by multimedia content, the use of decentralised services can lead to better solutions. Starting from the ongoing work of P2PSIP, we define a simple way to interconnect ..."
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Abstract: Providing innovating multimedia services is a high priority for service providers. Due to the high traffic volume created by multimedia content, the use of decentralised services can lead to better solutions. Starting from the ongoing work of P2PSIP, we define a simple way to interconnect different domains using peer-to-peer networks. We define the needed signalling to provide connectivity between different domains based on P2PSIP. This fact allows an easier deployment of global decentralised multimedia services. We validate the proposed solution through an analytical and experimental study of the routing performance and routing state for two possible scenarios.
A Dynamic Networking Substrate for Distributed MMOGs
, 2014
"... This paper proposes a distributed and dynamic networking architecture for massively multiplayer online games (MMOGs). The MMOG networks deal with the challenge of update message exchange among a large number of players that are subject to both mobility (constant change of virtual location) and churn ..."
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This paper proposes a distributed and dynamic networking architecture for massively multiplayer online games (MMOGs). The MMOG networks deal with the challenge of update message exchange among a large number of players that are subject to both mobility (constant change of virtual location) and churn (joining and leaving the physical network at will). Ideally, a player’s update messages should be multicasted to the player’s area of effect, which is a neighborhood around the player. But, this requires the system to have a centralized indexing service that keeps record of players residing in each region, making the system less scalable as the number of players increases. The use of geometric routing helps alleviate this requirement by exploiting location addressing and thus eliminating the need for IP-search queries. However, geometric routing comeswith a number of convergence and performance issues that require solutions for reducing hop-count and minimizing overall delay while providing guaranteed message delivery. In this paper, we propose a geometric routing overlay for message exchange among a large number ofMMOG players that not only provides reduced delay and guaranteed delivery, but also supports player mobility and churn. In addition, we enhance our greedy routing method to more efficiently support long distance messages. We demonstrate the effectiveness of our proposed scheme using both theory and simulations.
