A Distributed Coordination Protocol for a Heterogeneous Group of Peer Processes

Barolli

2009 International Conference on Advanced Information Networking and Applications

et al. 2009

Self Cite

In peer-to-peer (P2P) applications, peers make an agreement on one opinion. Agreement procedures have to be so flexible that persons can change their opinions. We discuss a flexible agreement protocol of multiple peers by taking advantage of human behaviors in a fully unstructured P2P network. There are forward, backward, mining, and observation strategies for each peer to find a value to make an agreement. In the forward strategy, a peer shows a new value to the other peers. In the backward one, a peer backs to a previous round. In order to back to the previous round, values taken after the round have to be withdrawn. In the mining one, a peer tries to find a tuple of previous values named a cut which satisfies the agreement condition. In the observation one, a peer does not take a new value. Since each peer autonomously takes one of the strategies at each round, the peers might take inconsistent strategies. For example, only if every peer takes the mining strategy, the mining strategy can be adopted. The mining strategy is inconsistent with the others. The peers have to do negotiation with each other to take consistent strategies. We discuss how peers cooperate to take consistent strategies at each round.

Section: Coordination Proceduresmentioning

confidence: 99%

“…The authors [12,2,3] discuss E-and P-types of precedent relations on values to show what value a peer can take after taking a value and present a forward strategy for each peer to find a new value according to the precedent relations. We introduce the backward, mining, and observation strategies to efficiently make an agreement.…”

Section: Introductionmentioning

confidence: 99%

Recoverable Cuts to Make Agreement among Peers

Barolli

2009 International Conference on Advanced Information Networking and Applications

et al. 2009

Self Cite

“…In the previous works [20,21], we mainly discuss how to reliably deliver messages in a group of multiple peers after the group has been established. A group is constructed in a way that first neighbors, i.e.…”

Section: Basic Ideasmentioning

confidence: 99%

“…As shown in Figure 10, since the depth D of peers p 20 , p 21 , and p 22 is 3 (D = 3), P (D = 3) = {p 20 , p 21 , p 22 }. Thus, the initiator peer p i needs to deliver a message to peers in the set P (D = 3) through peers in P (D = 2) and P (D = 1) .…”

Section: Tbb Algorithmmentioning

confidence: 99%

Trustworthy Group Making Algorithm in Distributed Systems

Hum. Cent. Comput. Inf. Sci.

Takizawa

2011

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Information systems are being shifted to scalable architectures like Cloud and peerto-peer (P2P) models. In this paper, we consider the P2P model as a fully distributed, scalable system different from centralized coordinated systems in Cloud and Grid systems. A P2P system is composed of peer processes (peers). Here, applications are realized by activities of peers and cooperations among multiple peers. In P2P systems, since there is no centralized coordination, each peer has to obtain information about other peers by itself. In the group cooperation, each group member peer has to be trustworthy so that malicious behavior of a member peer cannot effect overall outcome of the whole group. Here, it is important to consider the trustworthiness of each group member as a base of an agreement procedure in the distributed environment. The goal of a group and the way to archive the goal are decided by the group members. During the agreement procedure, opinions of member peers have to be collected in a group. Malicious and unexpected behaviors of member peers can negatively effect the output of a group. Hence, it is significant to discuss how to compose a group only by including more trustworthy peers. In this paper, by taking advantage of the trustworthiness concept of each peer, we propose a novel approach to composing a trustworthy group in the distributed agreement protocols.

“…In addition, a person does not arbitrarily change the opinions but rather changes the opinion with some opinion which depends on the previous opinions. The authors discuss the existentially (E-) precedent relation → E i and the preferentially (P-) precedent relation → P i on a domain D i of each process p i [11,1,2]. Here, a relation "v 1 → E i v 2 " shows that a process p i can take a value v 2 after v 1 .…”

Section: Introductionmentioning

confidence: 98%

A Distributed Coordination Protocol for Multiple Peer Processes

22nd International Conference on Advanced Information Networking and Applications (Aina 2008)

Takizawa

2008

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In this paper, we discuss a fully distributed unstructured P2P system where there is no centralized coordinator. Each process makes by itself a decision on an agreement value to realize some objectives by communicating with other processes in a group. Each process first takes a value v in a domain D i which is a collection of possible values and notifies the other processes of the value v. A process in turn receives values from other processes. Unless a set of the values satisfy an agreement condition, a process can take an other value v , differently from the traditional consensus protocols. In human societies, people change their opinions in an agreement procedure. Types of precedent relations on values are discussed to show which value v 2 to be taken after a value v 1 is taken. An existentially precedent relation (v 1 → E i v 2 ) shows a process p i can take a value v 2 after taking v 1 . In addition, values are ordered in the preferentially precedent relation (→ P ). A history of a process p i is a sequence of values which p i has taken. Some value may not be taken multiple times. Each value is characterized in terms of the maximum number of occurrences in a history. If a process p i finds some mistake on selecting a value at a previous round, the process would like to roll back to the previous round. A process takes a checkpoint at a round. The process p i can roll back to the checkpoint most recently taken. In this paper, we discuss the checkpoint mechanism in the coordination protocol. Based on the precedent relations and checkpoints, each process takes the most preferable value v in the values which are changeable from current value v.