PPT-CS 5204

Operating Systems Godmar Back Disks amp File Systems CS 5204 Fall 2015 Filesystems Consistency amp Logging CS 5204 Fall 2015 Filesystems amp Managing Faults Filesystems promise Persistence. Reasoning about concurrency and communication (Part 1).. CS5204 – Operating Systems. 1. CS 5204 – Operating Systems. 2. Theoretical Foundations of Concurrency. A formal study of concurrency enables:. Reasoning about concurrency and communication (Part 2).. CS5204 – Operating Systems. 1. CS 5204 – Operating Systems. 2. A Process with Alternative Behavior. A vending machine that dispenses chocolate candies allows either a 1p (p for pence) or a 2p coin to be inserted. After inserting a 1p coin, a button labelled “little” may be pressed and the machine will then dispense a small chocolate. After inserting a 2p coin, the “big” button may be pressed and the machine will then dispense a large chocolate. The candy must be collected before additional coins can be inserted. . 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. . . .. Oxford CircusGoodge StreetWarren StreetRegent’s ParkGreat Portland StreetEuston SquareGreen ParkPiccadilly CircusBaker StreetBond StreetMarble Arch ARYLEE R 5204 PAA414201OXFORD ST OXRD SUTH ST CS5204 – Operating Systems. 1. CS 5204 – Operating Systems. 2. Communicating Sequential Processes (CSP). single thread of control . autonomous . encapsulated . named . static . synchronous . reliable . The Global State Recording Algorithm. CS 5204 – Operating Systems. 2. The Model. Node properties . No shared memory . No global clock . node. channel. Channel properties: . FIFO . loss free . non­duplicating. Distributed Storage. 1. Dennis Kafura – CS5204 – Operating Systems. CS 5204 – Operating Systems. 2. Peer-to-Peer Systems. Definition. : “Peer-to-peer systems can be characterized as distributed systems in which all nodes have identical capabilities and responsibilities, and all communication is symmetric.” –. Maurice Herlihy (DEC), J. Eliot & B. Moss (UMass). Presenter: Mariano Diaz. CS 5204 – Fall, 2009. Part 1: Concepts and Hardware-based Approaches. Introduction. What’s a transaction?. Transaction: a finite sequence of machine instructions, executed by a single process, that satisfies the following:. Fast Dynamic Binary Translation for the Kernel. Piyus. . Kedia. and . Sorav. . Bansal. (SOSP 2013). Presenter: Apoorva Garg. Outline. Paper Presentation. Background. DBT Architecture. DBT Optimizations. CS5204 – Operating Systems. 1. CS 5204 – Operating Systems. 2. Fault Tolerance. erroneous state. error. valid state. failure. causes. fault. leads to. recovery. An error is a manifestation of a fault that can lead to a failure.. Security Policy Assertion Language. CS5204 – Operating Systems. 1. CS 5204 – Operating Systems. 2. The Grid. Resources and user belong to a variety of different independent organizations. Resources and users are connected via communication networks. Fault Tolerant Replication. CS 5204 – Fall, 2008. System Model. Messages. possible indefinite delay. possible duplication or loss. delivered messages not corrupted. . . .. replicas. client. Replicas. Article ArticleThememorytraceofastressfulepisodeAnneBierbrauer,Marie-ChristinFellner,RebekkaHeinen,OliverT.Wolf,andNikolaiAxmacherDepartmentofNeuropsychology,InstituteofCognitiveNeuroscience,Facultyof CS5204 – Operating Systems. 1. CS 5204 – Operating Systems. 2. A Process with Alternative Behavior. A vending machine that dispenses chocolate candies allows either a 1p (p for pence) or a 2p coin to be inserted. After inserting a 1p coin, a button labelled “little” may be pressed and the machine will then dispense a small chocolate. After inserting a 2p coin, the “big” button may be pressed and the machine will then dispense a large chocolate. The candy must be collected before additional coins can be inserted. .