PPT-Paxos

Made Simple Leslie Lamport Summary Piras Maha Outline History Problem Choosing A Value Learning Simple Example History Leslie Lamport Presented in 1990 Almost everyone dismissed it. Cheap Paxos a variant of the Paxos al gorithm guarantees liveness under the additional as sumption that the set of nonfaulty processors does not jump around too fast but uses only F 1 main pro cessors that actually execute the system and F auxiliar Made Simple. Gene Pang. Paxos. L. . Lamport. , The Part-Time Parliament, September 1989. Aegean island of . Paxos. A part-time parliament. Goal: determine the sequence of decrees passed. Lamport. related their protocol to fault-tolerant distributed systems. A Consensus Algorithm for . Fault Tolerant Replication. CS 5204 – Fall, 2008. System Model. Messages. possible indefinite delay. possible duplication or loss. delivered messages not corrupted. . . .. Advanced Topics in Computer Systems. Lecture 24. Paxos/Megastore. November . 26. th. , . 2012. John . Kubiatowicz. and Anthony D. Joseph. Electrical Engineering and Computer Sciences. University of California, Berkeley. Paxos. --- 1. Steve Ko. Computer Sciences and Engineering. University at Buffalo. Recap. NFS. Caching with write-through policy at close(). Stateless server. One power efficient design: FAWN. Embedded CPUs & Flash . COMS 6998-. 8. , Fall 2013. Instructor: Li . Erran. Li (. lierranli@cs.columbia.edu. ). http://www.cs.columbia.edu/~lierranli/coms6998-8SDNFall2013/. 10/. 29/. 2013: SDN . Traffic Management. Outline. Globally-Distributed Database. James C. Corbett, Jeffrey Dean, Michael Epstein, Andrew . Fikes. , Christopher Frost, JJ . Furman,Sanjay. . Ghemawat. , . Andrey. . Gubarev. , Christopher . Heiser. , Peter . Paxos Made Simple One-shot Paxos: solving consensus Multipaxos: Efficient state machine replication One-shot Paxos: solving consensus Multipaxos: Efficient state machine replication Consensus Get N nodes to agree on a value Consensus I FLP Impossibility, Paxos COS 418: Distributed Systems Lecture 7 Michael Freedman 2 Recall our 2PC commit problem C  TC: “go!” TC  A, B: “prepare!” A, B  P: “yes” Paxos and Replicated State Machine (RSM) Outline Basic Concepts of Replicated State Machine Paxos Made Simple Replicated State Machine We can replicate data, how can we guarantee it is correctly replicated? . Oct 22, 2018. What is consensus?. A group of people go to the same place for the same meal.. → A set of nodes have the same value for the same variable.. X=. 7. X=7. X=7. Why is it important?. In state machine replication (SMR):. Lecture 16. , Oct 22. nd. 2015 . How’d we get here?. Failures & single systems; fault tolerance techniques added redundancy (ECC memory, RAID, etc.). Conceptually, ECC & RAID both put a “master” in front of the redundancy to mask it from clients -- ECC handled by memory controller, RAID looks like a very reliable hard drive behind a (special) controller. over a. Distributed Shared Log. Paxos. Paxos is an. “. application framework”. that employs replication for . availability. .. It offers no . scalability. .. Paxos. Paxos. Paxos. Paxos. Corfu. Tango. Paxos. COS 418: Distributed Systems. Lecture . 10. Wyatt Lloyd. Let different replicas assume role of primary over time. System moves through a sequence of views. How do the nodes agree on view / primary?.