Top PDF Dynamic TTL-Based Search In Unstructured Peer-to-Peer Networks

Dynamic TTL-Based Search In Unstructured Peer-to-Peer Networks

Dynamic TTL-Based Search In Unstructured Peer-to-Peer Networks

{Imen.Filali, Fabrice.Huet}@sophia.inria.fr Abstract—Resource discovery is a challenging issue in un- structured peer-to-peer networks. Blind search approaches, including flooding and random walks, are the two typical algorithms used in such systems. Blind flooding is not scalable because of its high communication cost. On the other hand, the performance of random walks approaches largely depends on the random choice of walks. Some informed mechanisms use additional information, usually obtained from previous queries, for routing. Such approaches can reduce the traffic overhead but they limit the query coverage. Furthermore, they usually rely on complex protocols to maintain information at each peer. In this paper, we propose two schemes which can be used to improve the search performance in unstructured peer-to-peer networks. The first one is a simple caching mechanism based on resource descriptions. Peers that offer resources send periodic advertisement messages. These messages are stored into a cache and are used for routing requests. The second scheme is a dynamic Time-To-Live (TTL) enabling messages to break their horizon. Instead of decreasing the query TTL by 1 at each hop, it is decreased by a value v such as 0 < v < 1. Our aim is not only to redirect queries towards the right direction but also to stimulate them in order to reliably discover rare resources. We then propose a Dynamic Resource Discovery Protocol (DRDP) which uses the two previously described mechanisms. Through extensive simulations, we show that our approach achieves a high success rate while incurring a low search traffic.
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Efficient and Scalable Query Routing for Unstructured Peer-to-Peer Networks

Efficient and Scalable Query Routing for Unstructured Peer-to-Peer Networks

The second family of unstructured p2p networks comprises Gnutella-like networks that do not impose any structure on the overlay network [6]. The default search mechanism in Gnutella is to blindly forward queries to all neighbors within a certain number of hops. Although this mechanism handles network dynamics very well, search through blind flooding is quite inefficient. This has motivated a host of studies proposing various enhancements to search in unstructured networks. Major improvements include replacing the blind flooding with a random-walk [7] or an expanding ring search, tailoring the network construction to achieve properties of small world graphs [8], reflecting the capacities of heterogeneous nodes in topology-construction [9], and caching pointers to content located one hop away [9]. All of these proposals (except for caching) retain the “blind” nature of query forwarding in Gnutella. In other words, the forwarding of queries is independent of the query string and does not exploit the information contained in the query itself. The keywords in the query are used only for searching the local content index. The objective of this work is to design an efficient query- routing mechanism for unstructured peer-to-peer networks. We propose to build probabilistic routing tables at nodes, constructed and maintained through an exchange of updates among immediate neighbors in the overlay. These routing tables use a novel data structure — the Exponential Decay Bloom Filter (EDBF) — to efficiently store and propagate probabilistic information about content hosted in the neighbor- hood of a node. The amount of information in an EDBF (and the number of bits used to store this information) decreases exponentially with distance. Such exponential decrease in information with distance restricts the impact of network dynamics to the neighborhood of any departing or newly arriving node. The Scalable Query Routing (SQR) mechanism we design uses hints obtained from these probabilistic routing tables to forward queries. The use of probabilistic hints pro- vides a significant advantage over the completely blind nature of existing mechanisms, translating into large reductions in the average number of hops over which a query is forwarded before it is answered.
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Query routing  using query feedback and similarity in unstructured peer to peer networks

Query routing using query feedback and similarity in unstructured peer to peer networks

In this paper, we propose a query based query routing approach for unstructured peer-to-peer network. We consider two parameters to be used to selectively route query in the network. The parameters are based on the recent past query and the similarity of the past query with the query to be routed. The objective of our approach is to have a low cost but effective routing approach in unstructured peer-to-peer networks. Our approach also includes the method to take into account, the content of the query in which the query similarity is calculated as well as the query hits to determine connection reliability. Simulation results proved that our approach showed efficiency in terms of query time and network load over Most Query Hits query routing approach proposed by Yang & Molina [1], which also uses past query information for routing queries in unstructured peer-to- peer network.
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Performance Analysis of Controlled Scalability in Unstructured Peer to Peer Networks

Performance Analysis of Controlled Scalability in Unstructured Peer to Peer Networks

In unstructured peer-to-peer networks, the analysis of scalability is a challenging task due to the unpredictable nature of churn rate. Specifically, in the P2P file sharing applications, peers join and leave the overlay network in a dynamic fashion increase the complexity of the network and leads to a huge wastage of bandwidth during the search for a particular file. In this paper, we proposed a controlled scalability model in unstructured P2P networks for achieving efficient bandwidth utilization and high scalability. Performance measures such as peer availability and scalability are analyzed and compared with the BitTorrent system show that the proposed model overcomes the problems of bandwidth wastage and initial time flash crowd while maintaining the scalability of the network. Mathematical modeling and simulation results illustrates that the controlled scalability performs well in utilizing bandwidth during the event of polluted or infected files sharing than the uncontrolled scalability in the existing unstructured P2P networks.
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Improved Search Efficiency in Unstructured Peer to Peer Networks Using Search Result Path Caching

Improved Search Efficiency in Unstructured Peer to Peer Networks Using Search Result Path Caching

Abstract: The huge popularity of recent Peer-to-Peer (P2P) file sharing systems has been mainly driven by the scalability of their architectures and the flexibility of their search facilities. Such systems are usually designed as Unstructured P2P networks. So, designing an efficient search algorithm is a key challenge in unstructured peer-to-peer networks due to the unstructured paradigm. In this study, we proposed a Search Result Path Caching algorithm (SRPC). The proposed scheme combines the Dynamic Search (DS) algorithm and result path caching for effective search. This proposed algorithm takes the advantages from dynamic search and path caching technique works with the queried results. After the successful discovery of results the queries are returned to originator, according to our proposed algorithm the originator will stores the results for future references. In future stored references are used to search the information without querying the overall network. We analyze the performance of our algorithm based on some performance metrics including the success rate, search time and search efficiency. The numerical results shows that the proposed SRPC algorithm performs about 5 times better than DS, 125 times better than flooding and 275 times better than Random Walk (RW) in power-law graphs.
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Alpha Multipliers Breadth-First Search Technique for Resource Discovery in Unstructured Peer-to-Peer Networks

Alpha Multipliers Breadth-First Search Technique for Resource Discovery in Unstructured Peer-to-Peer Networks

then check the path length and rewards the path if it is shorter than the average length, the path will be penalised otherwise [6]. LARD eases the problem of network flooding. However, by using TTL like Mashayekhi and Habibi’s technique, LARD also has an issue of fault positive error [3]. Improved Adaptive Probabilistic Search (IAPS) utilises ant-colony optimisation to search space and search overhead [7]. The technique is proven to be better than popular random walk and Adaptive Probabilistic Search (APS) [5]. DHMCF is a resource discovery technique for a pure unstructured P2P network that responds to dynamic requests [8]. In this technique, there are 5 units to gather information, make decisions, find resources and balance the load. This technique, however, suffers from low robustness and security [3].
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Evaluating the Performance and Delay in Unstructured Peer to Peer Networks

Evaluating the Performance and Delay in Unstructured Peer to Peer Networks

Peer-to-peer (P2P) model is quickly emerging as a significant computing paradigm of the future Internet. Unlike traditional distributed computing, P2P networks aggregate large number of computers and possibly mobile or hand-held devices, which join and leave the network frequently. Nodes in a P2P network, called peers, play a variety of roles in their interaction with other peers. When accessing information, they are clients. When serving information to other peers, they are servers. When forwarding information for other peers, they are routers. This new breed of systems creates application-level virtual networks with their own overlay topology and routing protocols. An overlay topology provides mechanisms to create and maintain the connectivity of an individual node to the network by establishing network connections with a subset of other nodes (neighbors) in the overlay network.
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Secure, Efficient and Privacy-aware Framework for Unstructured Peer-to-Peer Networks

Secure, Efficient and Privacy-aware Framework for Unstructured Peer-to-Peer Networks

None of the above-mentioned leader selection algorithms is decision-based nor they are accomplished through an election process. Rather an assignment is given to a particular user to act as a leader or super node. The nominated node has no jurisdiction over the appointment. However, they can make a binary decision on selection or rejection of the nomination. Our focus is to nominate a node with higher capabilities but with the inclusion of reputation and trustworthiness. To the best of our knowledge, all of the leader selection mechanisms perform a binary decision-making process regarding leader or super node selection within unstructured P2P systems. Their system either approves or rejects the super node appointment. GIA is the only exception that uses node capacity to select super nodes. This has been implemented in Skype, which is a structured VoIP protocol. Most of the current literature introduces binary-type leader selection, considering only one attribute as criteria for being selected as a leader. However, SEP introduces a multi-dimensional approach in selecting super nodes and takes into account node capacity, location and node reputation based on trusted relationship in the selection process. The detailed description of selection criteria is explained in this section.
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Efficient way of Data Managing for Range Queries 
                      in Unstructured Peer to Peer Networks.

Efficient way of Data Managing for Range Queries in Unstructured Peer to Peer Networks.

in the network and f is the average fan-out) from the peer which invoked search. In fact, as shown in [1], a random walk of this length makes the probability of reaching any peer converge to a stationary distribution, which is uniform if the network graph is well connected. In our prototype, we set the length of the random walk to 1’. This allows us to randomly select peers from a network of up to 4 1’ peers even in the pessimistic case that the network reaches a condition with average fan-out equal to 4. Primitive send(P; o) transmits s-block o from the peer p which invoked the primitive to the peers whose IP addresses are in set P. In our prototype, this primitive properly avoids overloading p when P is large. This is achieved through decentralized dissemination. instead of sending jPj copies of o, p sends o to a subset of the peers in P which, in turn, keep a copy of o and forward it to different subsets of the remaining peers in P, and so on. We assume that each s- block is uniquely identified throughout the system, and we denote their identifiers as id(I sup ), id(inf i ), and id(h j ). [13]
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Scaling Unstructured Peer-to-Peer Networks With Multi-Tier Capacity-Aware Overlay Topologies

Scaling Unstructured Peer-to-Peer Networks With Multi-Tier Capacity-Aware Overlay Topologies

The key problem that has plagued a Gnutella like P2P sys- tems is Peer Heterogeneity. We have proposed simple yet effective multi-tier capacity-aware topologies for improving the P2P search performance. There are three main contribu- tions in this paper. First, we propose techniques to struc- ture overlay topologies taking peer heterogeneity into ac- count; such capacity aware topologies ensure that the per- formance of the P2P system is not hindered by less powerful peers. Second, we developed an analytical model to enable us to construct and maintain capacity-aware overlay topolo- gies with good node connectivity and better load balance. Third, we proposed a probabilistic routing algorithm that fur- ther reduces the bandwidth consumption of our P2P system. We used extensive simulation-based experiments and math- ematical analysis to construct and evaluate the goodness of capacity-aware topologies and routing algorithms over ran- dom topologies and broadcast-styled routing algorithms. Fi- nally, our design and techniques being simple and pragmatic can be easily incorporated into existing systems like Gnutella.
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Textual Based Retrieval System with Bloom in Unstructured Peer-to-Peer Networks

Textual Based Retrieval System with Bloom in Unstructured Peer-to-Peer Networks

Bloom Cast is a novel replication strategy to support efficient and effective full-text retrieval. Different from the WP scheme, random node sampling of a lightweight DHT is utilized by the Bloom Cast. Here we generate the optimal number of replicas of the content in the required workspace. The size of the networks is not depending on any factor since it is an unstructured P2P network. The size of the network is represent here as N. By further replicating the optimal number of Bloom Filters instead of the raw documents, Bloom Cast achieves guaranteed recall rate which results in reduction of the communication cost for replicating. We can design a query evaluation language to support full-text multi keyword search, based on the Bloom Filter membership verification. Bloom Cast hybrid P2P network has three types of nodes: they are structured peers, normal peers, and bootstrap peers. A Bloom Cast peer
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Survey of Various Search Mechanisms in Unstructured Peer to Peer Networks

Survey of Various Search Mechanisms in Unstructured Peer to Peer Networks

Random Walk (RW) is a conservative search algorithm, which belongs to DFS-based methods. By RW, the query source just sends one query message (walker) to one of its neighbors or an equal number of randomly chosen neighbors. If this neighbor does not own the queried resource, it keeps on sending the walker to one of its neighbors, except for the one the query message comes from, and thus, the search cost is reduced. The termination of a search is based on two different methods- TTL based and check method, in which the walker periodically contacts the query source that whether the termination condition has reached or not. The main drawback of RW is the long search time. Since RW only visits one node for each hop, the coverage of RW grows linearly with hop counts, which is slow compared with the exponential growth of the coverage of flooding. Moreover, the success rate of each query by RW is also low due to the same coverage issue. Increasing the number of walkers might help improve the search time and success rate, but the effect is limited due to the link degree and redundant path.
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Ontology-based Search Algorithms over Large-Scale Unstructured Peer-to-Peer Networks

Ontology-based Search Algorithms over Large-Scale Unstructured Peer-to-Peer Networks

Use of ontologies to overcome the limitations of existing knowledge representation meth- ods has been popular since the emergence of semantic web. While there have been many contributions in this direction over the last few years [52], [53], [54], many do not use the full potential of expressive capability of ontologies or are based on Boolean retrieval models. As surprising as it may sound, ontologies are a shallow form of semantic representation as long as they are not integrated with proper knowledge quantification methodologies and appro- priate quantitative reasoning techniques. Massive amounts of information available in web today are largely unstructured. Converting such a huge amount of heterogeneous unstruc- tured data distributed over a network at an affordable cost is a problem yet to be solved. The knowledge representation data structure devised for P2P environments should also pro- vide probabilistic reasoning to be acted upon them for query routing purposes. Probabilistic reasoning is a well-understood and theoretically-sound method for combining information from varying data sources with varying reliability. It has shown its applicability across many applications including query routing in P2P networks. However, only limited amount of work has been done to combine probabilistic reasoning capabilities with ontologies [55]. Heterogeneity of data and ontologies in distributed networks poses further challenges to the problem of probabilistic reasoning in P2P networks. While probability theory provides the pathway to produce solutions that indicate the degree of plausibility, ontologies use logical reasoning which provides only definite answers.
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Unstructured Peer-to-Peer Networks: Topological Properties and Search Performance

Unstructured Peer-to-Peer Networks: Topological Properties and Search Performance

Adamic et al. [1]. An early study of unstructured P2P network search perfor- mance was done by Lv et al. [15], comparing search performance on generic power-law, random, and Gnutella networks. 4 More recently, several groups have continued to study search performance with a focus on comparing power-law and random topologies with deployed P2P systems such as Gnutella [5,25,29]. Initial studies on search in open MAS have also focused on generic topologies [9,23]. Several projects have investigated the topological characteristics of the Internet [10] and implementations of P2P filesharing networks [11]. What has been miss- ing in all of this work is a general comparative study of proposed unstructured P2P models, their topologies, and performance of search algorithms. This paper is an initial step in filling this gap in our understanding of decentralized search in unstructured P2P networks and open MAS.
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Semantic search and composition in unstructured peer-to-peer networks

Semantic search and composition in unstructured peer-to-peer networks

2.2 P2P Computing P2P computing has been investigated for resolving computing problems that often request distribut- ed data processing and resource management, real-time collaboration, ad-hoc networking, paral- lelization, scalability and fault-tolerance. A P2P network commonly comprises a set of networked computation devices. Formally, it contains a set P of peers (nodes) interconnected via a set C of connections. Identified with an IP address or a public key, each individual peer p ∈ P is able to act as both a provider and a consumer of resources [323], including its processing power, disk storage, memory, network bandwidth and data. A connection c ∈ C between two peers indicates that (i) each of them knows the network address of the other; (ii) both of them agree on certain rules for exchang- ing messages, by means of the underlying network protocol (e.g. the IP layer in the OSI model 59 ); and (iii) each of them is a (direct) neighbor peer of the other. Maintained by a peer, an item i in a P2P network refers to a piece of data plus its descriptions. All items in the network comprise a multiset I. The idea of P2P computing was popularized by file sharing systems. A common feature of them is that they "allow millions of Internet users to connect directly, forming groups and collaborating to become user-created search engines, virtual supercomputers and file systems" [272]. From its ap- plication perspective, the P2P family covers the early-stage systems ARPANET [343] and USENET [236], as well as the systems for content sharing (Gnutella, FreeNet, Morpheus, Napster [317], Bit- Torrent [68], Kad [379] (Kademlia [251]), the Storm botnet [211], Chord [344], Pastry [314], P-Grid [1]), media streaming (TVU Networks 60 , CoolStreaming 61 , PeerCast 62 , FreeCast 63 , Osiris 64 ), instant messaging (ICQ 65 , Fire 66 ), and high-availability distributed data storage (Bigtable [55], GFS [118] [100]).
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Gossip-based Reputation Aggregation for Unstructured Peer-to-Peer Networks*

Gossip-based Reputation Aggregation for Unstructured Peer-to-Peer Networks*

We propose a novel reputation aggregation scheme called GossipTrust. This system computes global reputation scores of all nodes concurrently. By resorting to a gossip protocol and leveraging the power nodes, GossipTrust is adapted to peer dynamics and robust to disturbance by malicious peers. Simulation experiments demonstrate the system as scalable, accurate, robust and fault-tolerant. These results prove the claimed advantages in low aggregation overhead, storage efficiency, and scoring accuracy in unstructured P2P networks. With minor modifications, the system is also applicable to structured P2P systems with projected better performance.
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Dynamic Search In Un-Structured Peer-To-Peer Networks

Dynamic Search In Un-Structured Peer-To-Peer Networks

ABSTRACT: Peer-to-peer networks are becoming popular today because thesenetworks offer sharing of resources through direct exchange. In unstructured peer-to-peer networks, each node does not have global information about the whole topology and the location of other nodes. A dynamic property of unstructured P2P networks, capturing global behaviour is also difficult. Search algorithms to locate the queried resources and to route the message to the target node. Flooding and Random walk are two typical examples of blind search algorithms by which query messages are sent to neighbours without any knowledge about the possible locations of the queried resources or any preference for the directions to send. Both algorithms are not suitable to route a message to target. Dynamic search improves the performance of searching by using the super peers which operates both as a server to a set of clients and an equal in the network of super peers. Dynamic search reduces the number of messages by using the knowledge based searching. Each node could relay query messages more efficiently to reach the target node.
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Secure Reputation Mechanism For Unstructured Peer To Peer System

Secure Reputation Mechanism For Unstructured Peer To Peer System

1.2.2 Unstructured Systems An unstructured peer to peer network is formed when the overlay links are established arbitrarily. Such networks can be easily constructed as a new peer that wants to join the network can copy existing links of another node and then form its own links over time. In an unstructured peer to peer network, if a peer wants to find a desired piece of data in the network, the query has to be flooded through the network to find as many peers as possible that share the data. The main disadvantage with such networks is that the queries may not always be resolved. Popular content is likely to be available at several peers and any peer searching for it is likely to find the same thing. But if a peer is looking for rare data shared by only a few other peers, then it is highly unlikely that search will be successful. Since there is no correlation between a peer and the content managed by it, there is no guarantee that flooding will find a peer that has the desired data. Flooding also causes a high amount of signaling traffic in the network and hence such networks typically have very poor search efficiency. Many of the popular peer to peer networks are unstructured. The main requirements are:1. A self-certification- based identity system protected by cryptographically blind identity mechanisms, A light weight and simple reputation model. 2. An attack resistant cryptographic protocol for generation of authentic global reputation information of a peer.
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A Secure Method for Routing Queries and Dynamic TTL-Based Search in P2P Networks

A Secure Method for Routing Queries and Dynamic TTL-Based Search in P2P Networks

We also provide modifications to the algorithm that make it amenable to implement and the sharing content are also to be used to its successful sharing sources from one node to another node file the documents were available the certain file and its including data in the peer to peer networks with calculates the mobility and bandwidth rate of the each node in unstructured peer to peer networks. These caches only store the resource description, not the owner, maintaining a small footprint and allowing aggregation. A dynamic TTL scheme removes the horizon limitation of messages which are more likely to reach a peer providing the needed resource. We are currently exercising Swap links by using it as a basis for a number of P2P applications. The Swap links algorithm is being used in building a toolkit for NAT traversal in P2P applications, and a P2P file backup system. We invite researchers to use our Swap links toolkit in their unstructured P2P applications. In a peer-to-peer system, if you wish more storage space, you need only add another node. Another consequence of this is that such a system quite often has a built-in redundancy. Having files on multiple nodes also distributes the download traffic. Unlike a centralized system where all download requests would go to the central server, in peer-to-peer each download request is passed among peers. Improvements can be appended by changing the existing modules or adding new modules. One important development that can be added to the project in future is secure the data from the External attack and networks also have to connect the network with more unstructured system.
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A Comparison of Peer-to-Peer Search Methods

A Comparison of Peer-to-Peer Search Methods

Figure 5: Number of hits as the number of re- quests per object increases in a static network 5. CONCLUSIONS This paper presents an overview of current search techniques for unstructured P2P networks. Our analysis and simula- tions focus on three metrics: accuracy, bandwidth produc- tion and discovered objects. Flood-based schemes (e.g. Int- BFS, Mod-BFS ) exhibit high performance at a very high cost. Other blind methods (e.g. Random Walks, GUESS ) are simple and can greatly reduce bandwidth production but generally fail to adapt to different workloads and environ- ments. Conversely, most informed methods achieve great re- sults but incur large overheads due to index updates. DRLP and s-APS require no costly updates. The former performs best in relatively static environments, while the latter uses its adaptive nature to achieve good performance at low cost. s-APS particularly favors nodes with a prolonged stay in the network and the discovery of popular objects.
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