Prologue to Shared Systems

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What is a P2P system. A P2P system is an extensive dispersed framework. It utilizes the immeasurable asset of PCs conveyed at the edge of the Internet to assemble a system that permits asset sharing with no focal authorityClient-Server versus Distributed. An associate is both a customer and a server. Control is decentralized.Much more than a framework for sharing pilfered music..

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´╗┐Prologue to Peer-to-Peer Networks

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What is a P2P arrange A P2P system is a vast appropriated framework. It utilizes the immense asset of PCs disseminated at the edge of the Internet to assemble a system that permits asset sharing with no focal power Client-Server versus Distributed . An associate is both a customer and a server. Control is decentralized. Considerably more than a framework for sharing pilfered music .

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Why does P2P require consideration?

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Network of associates. Every connection between companions comprises of at least one IP joins. The overlay organize dwells in the application layer . A P2P system is an overlay arrange Bob Alice Carol

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Well-known P2P Systems Napster Gnutella KaZaA eDpnkey Chord Tapestry CAN Pastry BitTorrent

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Some essential issues Search Storage Security Applications

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A Distributed Storage Service Bob Alice David Carol

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Promises Consider File Sharing as an Example Available every minute of every day Durable in spite of machine disappointments Information is ensured Resilient to Denial of Service

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Additional Goals Massive versatility Anonymity Deniability Resistance to control

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Challenges A P2P organize must act naturally sorting out. Join and leave operations must act naturally oversaw. The foundation is untrusted and the parts are problematic. The quantity of flawed hubs becomes straightly with framework measure. However, the total conduct must be dependable.

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Challenges Tolerance to disappointments and agitate Efficient directing regardless of the possibility that the structure of the system is unusual. Managing freeriders Load adjusting Security issues

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Looking up information How would you find information/records/questions in an extensive P2P framework worked around a dynamic arrangement of hubs in an adaptable way with no brought together server or progressive system? Napster file servers utilized a focal database . Faulty versatility and poor strength. Check how names are turned upward in web's DNS.

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Napster Users Directory server Stores files of tunes just Developed by Shawn Fanning in 1999, Shut down following 2 years for copyright encroachment . Brought together index servers were a bottleneck.. I N T E R N E T Root/Redirector Directory server Directory server

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Gnutella Truly decentralized framework. An inquiry like where is Double Helix ? depends on the flooding of the inquiry on a diagram of self-assertive topology. Evident adaptability issue, and the wastage of data transfer capacity brought about genuine wasteful aspects .

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Gnutella diagram twofold helix Client searching for " twofold helix "

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Unstructured versus Organized Unstructured P2P systems permit assets to be put at any hub. The system topology is discretionary, and the development is unconstrained. Organized P2P systems disentangle asset area and load adjusting by characterizing a topology and characterizing rules for asset position .

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Distributed Hash Table (DHT) Object-to-machine mapping utilizes exceptional keys. H (protest name) = key (H = hash work) H (machine name) = key Object name mapped to key k is put in machine whose name is mapped to key k. Improves question area.

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Distributed Hash Table (DHT) 0 N-1 c keyspace a Machine name hashed to b Object name hashed to b Basic thought b