1. Final Exam Review
CptS 464/564
April 24, 2019

2. Distributed Systems Paradigms: © 2019 David E. Bakken
Overview
First: Please do course evaluations!
myWSU portal
“Manage Classes” then “Course Evaluations” tab on left
Exam
Wednesday May 1, 8:10-10:00am
Same rooms unless I tell you otherwise by
Final is NOT comprehensive
But don’t forget everything you learned for the midterm
Exceptions
Local vs. Remote call in first day intro slides, what a proxy is, etc
Logical Time
Vector timestamps
Lattices
Compared to midterm
110/75 of the time
CptS 464/564 Fall 2019
Distributed Systems Paradigms: © 2019 David E. Bakken

3. Distributed Systems Paradigms: © 2019 David E. Bakken
Overview(2)
Main Categories in Final Exam (in order covered)
GridStat
RTI Use Cases
Study Slide #18 (Pluggable Transport Framework) and think in terms of middleware heterogeneity
Chapter 15: Coordination and Agreement
Chapter 4: Interprocess Communication (IPC) (PARTIAL)
Chapter 5: Remote Invocation (PARTIAL)
Chapter 6: Indirect Communication
Chapter 10: Peer-to-Peer
Cloud, Edge, and Fog Computing (later today)
Programming Projects
Basics/Lessons from pub-sub
CptS 464/564 Fall 2019
Distributed Systems Paradigms: © 2019 David E. Bakken

4. Distributed Systems Paradigms: © 2019 David E. Bakken
GridStat
How and why it is different from RTI DDS pub-sub
How and why it is different from traditional “reliable” streaming (TCP) or reliable multicast (hint: think about post-error correction)
Can it integrate with legacy communications sytems? How?
564 is responsible for the paper.
CptS 464/564 Fall 2019
Distributed Systems Paradigms: © 2019 David E. Bakken

5. Chapter 4: Interprocess Communication
Multicast communications [4.4]
NOT the Java API
CptS 464/564 Fall 2019
Distributed Systems Paradigms: © 2019 David E. Bakken

6. Chapter 5: Remote Invocation
Request-reply protocols [5.2]
low-level client-server interactions
Implementation issues: lost messages, etc.
built on top of message send and receive ops (Ch4)
SUMMARY page of HTTP RR
Remote Procedure Call (RPC) [5.3]
Make a remote procedure look (almost) like a local one to call (what does this entail?)
Call semantics (VERY IMPORTANT)
Remove Method Invocation (RMI) [5.4]
Make a remote object look (almost) like a local one to invoke
Note: ‘RMI’ is generic category, Java RMI is a specific instance
What is a lease, and how/why is it used? Alternative?
Not covering Java RMI: nobody needs to know this
CptS 464/564 Fall 2019
Distributed Systems Paradigms: © 2019 David E. Bakken

7. Chapter 6: Indirect Communication
Context ….. Time and space uncoupling
Group communication
Niche/purpose, main abstraction, main properties/mechanisms, different “flavors” (open vs. closed group, etc)
NOT JGroups example details/syntax: just there to make concrete the concepts we discuss
Publish-subscribe systems
Main ideas, niche/purpose, different flavors, … implementation choices & tradeoffs
Message queues
Main ideas, niche/purpose, contrasted with pub-sub & group comm, IBM Websphere
JMS NOT testable: there to reinforce concepts
Distributed Shared Memory: basic ideas, contrast w/above
CptS 464/564 Fall 2019
Distributed Systems Paradigms: © 2019 David E. Bakken

8. Chapter 10: Peer-to-Peer Systems
Big picture: why do they exist?
Napster and its legacy
Peer-to-Peer Middleware (3G P2P)
Goals, requirements, etc
Routing Overlays
What they are, purpose, etc
Comparing and contrasting textbook’s with GridStat’s
Case Studies
Pastry
Tapestry
Runtime issues: handling failure (or lack thereof), load balancing, background maintenance, …
Unstructured P2P basics, contrasted with structured
Basics of Squirrel, OceanStore
CptS 464/564 Fall 2019
Distributed Systems Paradigms: © 2019 David E. Bakken

9. Chapter 15: Coordination and Agreement
Basics: failure detectors
15.2: Distributed mutual exclusion
15.3: Elections
15.4: Group communication (and coord./agreement with it)
CptS 464/564 Spring 2016
Introduction to DSs: © 2016 David E. Bakken