Reliable and Efficient Way to Broadcast Messages in a Group by Trust-Based Broadcast (TBB) Scheme

Nowadays information systems are being shifted to distributed architectures, i.e. Grid and Peer-to-peer (P2P) models to obtain the benefits like scalability, autonomy, and fault-tolerance. We consider the P2P model as a fully distributed, scalable system, which is composed of peer processes (peers). Here, a group of multiple peers cooperate with each other. Peers have to efficiently and flexibly deliver messages to every peer of the group in P2P overlay networks. In order to efficiently and reliably broadcast messages in a scalable group, we take advantage of the multipoint relaying (MPR) mechanism. Here, each peer sends messages to only a subset of its acquaintances. However, if a peer which forwards messages to other peers is faulty, the peers cannot receive messages. In this paper, we newly discuss a trustworthiness-based broadcast (TBB) algorithm where only trustworthy peers forward messages. That is, untrustworthy peers are peers which cannot forward the messages due to some faults. Here, the transmission fault implied by faults of untrustworthy peers can be reduced. We evaluate the TBB algorithm in terms of the number of messages transmitted

Introduction: Unrecorded Lives

When anthropology student (and later, novelist) Amitav Ghosh set out from Oxford to Egypt in 1980 to find a suitable subject for his research, he may not have suspected the impact the trip would have on his life. He succeeded in completing the required tome for his degree and then went on to write In an Antique Land (1992), an unusually constructed book that deals with themes of historical and cultural displacement, with alienation and something we might these days, under the influence of postcolonial theory, call subaltern cosmopolitanism. Others might recognize the genre in which Ghosh is writing as one we have all tried our hand at, in one form or another: a record of discomfort in confronting the inconsistencies of another person\u27s-the other person\u27s-reality. The book is hardly recognizable as a novel; nor is it simply a historical investigation, since it blends an anthropological record with a travelogue, a diary, and speculations. Within the parameters of history, Ghosh told one interviewer, I have tried to capture a story, a narrative, without attempting to write a historical novel. You may say, as a writer, I have ventured on a technical innovation (Dhawan 1999: 24). In India in Africa, Africa in India we are attempting a parallel innovation : using what we know of the past to inform our understanding of the present Indian Ocean world; examining today\u27s imaginative interpretations of India by Africans and Africa by Indians to speculate on how, historically, these regions understood each other. Ghosh gathered evidence relating to a Jewish merchant operating in the twelfth century in Aden, and he was seeking to document, more remarkably, the merchant\u27s barely recoverable Indian slave. In the process, Ghosh learns as much about the interpretation his visit gets from the Africans he meets as he does about the merchant Ben Yiju\u27s reception in India and the role of the slave Bomma in the world of Indian Ocean commerce seven hundred or so years ago-for Ghosh was as much an object of fascination to the Egyptians as they were to him. There has been a coming and going for centuries, sometimes enforced, sometimes enthusiastically entered into, and one might have thought that this would have made for greater understanding among the various parties. But exactly the opposite was the case when the young doctoral student sat across from the aged imam in the Egyptian village and was told by him to stop doing the strange things that the villagers had heard were done by Hindus. Did his people bury their dead, or cremate them, he was asked. Was he circumcised? Did they worship cows? Is there military service for all in India, as there is in Egypt? Why did they not purify (i .e., infibulate or circumcise) their women? In fact, the imam and his villagers seemed to encourage him to remain apart from them, making sure that the young interloper did not enjoy the sense of community that they created during Ramadan. As Ghosh puts it, to belong to that immense community was a privilege they had to re-earn every year, and the effort made them doubly conscious of the value of its boundaries (A. Ghosh 1992: 76)