PPT-Paxos

Made Simple Gene Pang Paxos L Lamport The PartTime Parliament September 1989 Aegean island of Paxos A parttime parliament Goal determine the sequence of decrees passed Lamport related their protocol to faulttolerant distributed systems. 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 Ali Ghodsi. alig@cs.berkeley.edu. Replicated State Machine (RSM). Distributed Systems 101. Fault-tolerance. . (partial, byzantine, recovery,...). Concurrency. (ordering, asynchrony, timing,...). Generic. 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?. Globally-Distributed Database. James C. Corbett, Jeffrey Dean, Michael Epstein, Andrew . Fikes. , Christopher Frost, JJ . Furman,Sanjay. . Ghemawat. , . Andrey. . Gubarev. , Christopher . Heiser. , Peter . James C. Corbett et al . OSDI 2012. Presenter: Akshay Ravichandran. Outline. What is Spanner?. Why Spanner?. Implementation. External Consistency. Concurrency Control. Evaluation. Related Work. Future Work. Cezara. . Drăgoi. , INRIA ENS CNRS. Thomas A. . Henzinger. , IST Austria. Damien Zufferey. , MIT CSAIL. SNAPL, 2015.05.04. Fault-tolerant distributed algorithms. How to get it right when things go wrong ?. Fault Tolerant Replication. CS 5204 – Fall, 2008. System Model. Messages. possible indefinite delay. possible duplication or loss. delivered messages not corrupted. . . .. replicas. client. Replicas. 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 View Change Protocols and Consensus COS 418: Distributed Systems Lecture 11 Mike Freedman Today View changes in primary-backup replication Consensus 2 Review: Primary-Backup Replication Nominate one replica 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. Each 42the OI 2DSeuTli and zPage wIIPwC hwaccuracy Page wcash Seive trading Page won iiaiiOtiS urior Oii7i bligaiioris 1Page wPaxos Page wIn MIX32 bSPage wiv ZZ Page wParticipant vJii reyuird O c27gQ