1 / 10

Focus on Distributed Hash Tables

Focus on Distributed Hash Tables. Distributed hash tables (DHT) provide resource locating and routing in peer-to-peer networks But, more than object locating and routing Basically, a routing network Outline Three papers Mobile Grid Broadcast

halla-morin
Download Presentation

Focus on Distributed Hash Tables

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Focus on Distributed Hash Tables • Distributed hash tables (DHT) provide resource locating and routing in peer-to-peer networks • But, more than object locating and routing • Basically, a routing network • Outline • Three papers • Mobile Grid • Broadcast • An architecture based on DHT for grid resource location and allocation for massively distributed applications • One implementation • Grid resource location and allocation

  2. Wireless Grid • Vision: provide a easy way to access resource in the grid • PUT and GET: put/get a resource from/into the grid • Fundamental service: routing! • Comprise of stationary Internet hosts and wireless devices • Wireless devices can change their network attachment points • A potential application: NCHC’s EcoGrid • Internet severs + sensors in the wild • Our solution to provide a wireless grid • Based on distributed hash tables (DHT)

  3. Wireless Grid (cont’d) • Nodes can change their network addresses • Research problem • Given the network bandwidth budget (Bi) of each node i to maintain the DHT • How to efficiently utilize Bi of each node i to provide efficient routing • By efficiency, the route takes nearly zero timeouts An example of DHT Failed route from 1 to 12 Successful route

  4. Wireless Grid (cont’d) • Preliminary results • PHT: percentage of hop counts due to timeouts • PBT: percentage of maintenance bandwidth due to timeouts • Manuscripts in preparation • Mobility churn in DHTs • Nearly, optimal peer state supervision for mobile DHTs Our sol.

  5. Broadcast in Dynamic P2P Networks • Broadcast is a basic building block for many P2P applications • Message broadcast • Query routing in unstructured P2P networks • Diagnostics for overlay network structure • … • Broadcast in P2P networks • Each message has a TTL value • TTL decreases when the message is forwarded every time • A message is not forwarded if TTL = 0

  6. Research problem Given a TTL value How to maximize the broadcast scope while to minimize the maintenance bandwidth? Intuition behind: to maximize the broadcast scope requires the overlay network being maintained robustly! Broadcast … (cont’d)

  7. There is no easy way to maximize the broadcast scope and meanwhile to minimize the maintenance bandwidth We investigate several scalable failure detection and recovery mechanisms in the context of DHT Paper under reviewed: scoped broadcast in dynamic peer-to-peer networks Broadcast … (cont’d)

  8. P2P Mechanism for Grid Resource Location and Allocation • Overview

  9. P2P Mechanism for Grid Resource Location and Allocation (cont’d) • Organizes the allocated resources as a tree-like overlay • Submit tasks using Armada agents • Send the agents to the tree root • The tree root helps distribute the agent codes to its children

  10. Implementation • Targeted environment: NCHC UniGrid • Status: • A DHT Prototype for a cluster environment is available • P2P mechanism for Grid resource location and allocation • Hopefully, can be tested in UniGrid

More Related