PPT-Distributed Hash Tables

Chord and Dynamo Costin Raiciu Advanced Topics in Distributed Systems 18122012 Motivation file sharing Many users want to share files online If a files location is known downloading is easy. Spencer Dawson. Summary. What are rainbow tables?. A time and memory tradeoff in password cracking.. A piecewise approach to one-way hashes. What are the advantages/disadvantages. Best uses. Limitations. Case Study: Amazon Dynamo. Steve Ko. Computer Sciences and Engineering. University at Buffalo. Recap. CAP Theorem?. Consistency, Availability, Partition Tolerance. Pick two. Eventual consistency?. Availability and partition tolerance over consistency. Comp 550. Dictionary . Dictionary:. Dynamic-set data structure for . storing items indexed using . keys. .. Supports . operations: Insert, Search, and . Delete . (. take . O. (1) time. ). .. Applications:. Passwords stored in computers are changed from their plain text form to an encrypted value.. These values are called hashes, and there is a unique plain text value for every hash.. A rainbow table is a lookup table offering a time-memory tradeoff used in recovering the plaintext password from a password hash generated by a hash function . Plan. I spent the last decade advising on numerous cases where hash tables/functions were used. A few observations on . What data structures I’ve seen implemented and where. What do developers think, were they need help. 11/8/2017. Recap: Parallel Query Processing. Three main ways to parallelize. 1. Run multiple queries, each on a different thread. 2. Run operators in different threads (“pipeline”). 3. Partition data, process each partition in a different processor. Hash Tables. . . 0. 1. 2. 3. 4. 451-229-0004. 981-101-0002. 025-612-0001. © 2014 Goodrich, Tamassia, Godlwasser. Presentation for use with the textbook . Data Structures and Algorithms in Java, 6. n. . . [from the . techspeak. ] (var. ‘hash clash’) . When used of people, signifies a confusion in associative memory or imagination, especially a persistent one.” . . -. The Hacker's Dictionary . COS . 518. : . Advanced Computer Systems. Lecture . 15. Daniel Suo. [Credit: . All slides copied wholesale from Kyle Jamieson and . Mike Freedman.. Selected . content adapted from B. Karp, R. Morris]. Instructor: Lilian de Greef Quarter: Summer 2017 CSE 373: Data Structures and Algorithms Lecture 6: Finishing Amortized Analysis; Dictionaries ADT; Introduction to Hash Tables Today: Finish up Amortized Analysis CSE 373: Data Structures and Algorithms. Thanks to Kasey Champion, Ben Jones, Adam Blank, Michael Lee, Evan McCarty, Robbie Weber, Whitaker Brand, Zora Fung, Stuart . Reges. , Justin Hsia, Ruth Anderson, and many others for sample slides and materials .... COS 418: . Distributed Systems. Lecture 7. Kyle Jamieson. [Credit: Selected content adapted from B. Karp, R. Morris]. Peer-to-Peer Systems. Napster, Gnutella, BitTorrent, challenges. Distributed Hash Tables. Distributed Hash Tables. Chord, . Kelips. , Dynamo. Galen Marchetti, Cornell University. 1960s – 1999: Research Origins. ARPANET. every node requests and serves content. No self-organization. USENET. A common approach is to use a . Distributed Hash Table. (DHT). to organize . nodes. Traditional . hash functions convert a key to a hash value, which can be used as an index into a hash table.. Keys are unique.