Course Missive CS2750 Spring In Deo Speramus Brown

30-Apr-15© 2014 Maurice Herlihy2 Our Mission Learn how to –Come up-to-speed on a research area –Read a research paper –Map out an area from a paper –Present results to an audience

30-Apr-15© 2014 Maurice Herlihy3 The Two Generals Red army wins If both sides attack together

30-Apr-15© 2014 Maurice Herlihy4 Communications Red armies send messengers across valley

30-Apr-15© 2014 Maurice Herlihy5 Communications Messengers don’t always make it

30-Apr-15© 2014 Maurice Herlihy6 Your Mission Design a protocol to ensure that Red armies attack simultaneously

30-Apr-15© 2014 Maurice Herlihy7 Theorem There is no non-trivial protocol that ensures that the Red armies attack simultaneously

30-Apr-15© 2014 Maurice Herlihy8 Proof Strategy Assume a protocol exists Reason about its properties Derive a contradiction

30-Apr-15© 2014 Maurice Herlihy9 Proof 1.Consider the protocol that sends fewest messages

30-Apr-15© 2014 Maurice Herlihy10 Proof 1.Consider the protocol that sends fewest messages 2.It still works if last message lost

30-Apr-15© 2014 Maurice Herlihy11 Proof 1.Consider the protocol that sends fewest messages 2.It still works if last message lost 3.So just don’t send it –Messengers’ union pleased

30-Apr-15© 2014 Maurice Herlihy12 Proof 1.Consider the protocol that sends fewest messages 2.It still works if last message lost 3.So just don’t send it –Messengers’ union happy 4.But now we have a shorter protocol!

30-Apr-15© 2014 Maurice Herlihy13 Proof 1.Consider the protocol that sends fewest messages 2.It still works if last message lost 3.So just don’t send it –Messengers’ union happy 4.But now we have a shorter protocol! 5.Contradicting #1

30-Apr-15© 2014 Maurice Herlihy14 Advisor You May Find Yourself … I want a real-time ROTFL- compliant Two Generals protocol using UDP datagrams running on our enterprise-level fiber tachyion network... You

30-Apr-15© 2014 Maurice Herlihy15 Advisor You May Find Yourself … I want a real-time ROTFL- compliant Two Generals protocol using UDP datagrams running on our enterprise-level fiber tachyion network... You I’m so Pwned…

30-Apr-15© 2014 Maurice Herlihy16 I want a real-time ROTFL- compliant Two Generals protocol using UDP datagrams running on our enterprise-level fiber tachyion network... You might say Yes, Ma’am, right away! YouAdvisor

30-Apr-15© 2014 Maurice Herlihy17 I want a real-time ROTFL- compliant Two Generals protocol using UDP datagrams running on our enterprise-level fiber tachyion network... You might say Yes, Ma’am, right away! Advantage: Buys time to find another advisor. No one really expects software to work anyway Advantage: Buys time to find another advisor. No one really expects software to work anyway YouAdvisor

30-Apr-15© 2014 Maurice Herlihy18 I want a real-time ROTFL- compliant Two Generals protocol using UDP datagrams running on our enterprise-level fiber tachyion network... You might say Yes, Ma’am, right away! Advantage: Buys time to find another job No one really expects software to work anyway Advantage: Buys time to find another job No one really expects software to work anyway Disadvantage: You’re doomed Disadvantage: You’re doomed YouAdvisor

30-Apr-15© 2014 Maurice Herlihy19 I want a real-time ROTFL- compliant Two Generals protocol using UDP datagrams running on our enterprise-level fiber tachyion network... You might say I can’t find a fault-tolerant algorithm, I guess I’m just a pathetic loser. YouAdvisor

30-Apr-15© 2014 Maurice Herlihy20 I want a real-time ROTFL- compliant Two Generals protocol using UDP datagrams running on our enterprise-level fiber tachyion network... You might say I can’t find a fault-tolerant algorithm, I guess I’m just a pathetic loser. Advantage: No need to take CS275 Advantage: No need to take CS275 YouAdvisor

30-Apr-15© 2014 Maurice Herlihy21 I want a real-time ROTFL- compliant Two Generals protocol using UDP datagrams running on our enterprise-level fiber tachyion network... You might say I can’t find a fault-tolerant algorithm, I guess I’m just a pathetic loser. Advantage: No need to take CS275 Advantage: No need to take CS275 Disadvantage: Advisor fires you, uses grant money to hire undergraduates Disadvantage: Advisor fires you, uses grant money to hire undergraduates YouAdvisor

30-Apr-15© 2014 Maurice Herlihy22 I want a real-time ROTFL- compliant Two Generals protocol using UDP datagrams running on our enterprise-level fiber tachyion network... You might say Using skills honed in CS275, I discovered prior work that suggests we had better rethink the problem spec. YouAdvisor

30-Apr-15© 2014 Maurice Herlihy23 I want a real-time ROTFL- compliant Two Generals protocol using UDP datagrams running on our enterprise-level fiber tachyion network... You might say Using skills honed in CS275, I discovered prior work that suggests we had better rethink the problem spec. YouAdvisor Tenure- track!

30-Apr-15© 2014 Maurice Herlihy24 Our Mission Learn how to –Come up-to-speed on a research area –Read a research paper –Map out an area from a paper –Present results to an audience

30-Apr-15© 2014 Maurice Herlihy25 Reading a Research Paper Many research papers are badly written –Conference deadlines –Conference page limits –Brilliant but inarticulate authors

30-Apr-15© 2014 Maurice Herlihy26 Leslie Lamport Review

30-Apr-15© 2014 Maurice Herlihy27 Leslie Lamport Review Badly-written, misunderstood paper that few had read.

30-Apr-15© 2014 Maurice Herlihy28 Continued …

30-Apr-15© 2014 Maurice Herlihy29 Continued … Eh?

30-Apr-15© 2014 Maurice Herlihy30 Continued … Why indeed?

30-Apr-15© 2014 Maurice Herlihy31 Continued … Why not?

30-Apr-15© 2014 Maurice Herlihy32 Continued … Marketing FAIL

30-Apr-15© 2014 Maurice Herlihy33 Hard Cases Make Bad Law This example does not mean –Every badly written paper has hidden value

30-Apr-15© 2014 Maurice Herlihy34 Hard Cases Make Bad Law This example does not mean –Every badly written paper has hidden value But some do

30-Apr-15© 2014 Maurice Herlihy35 Hard Cases Make Bad Law This example does not mean –Every badly written paper has hidden value But some do And some well-written papers –Have little to say

30-Apr-15© 2014 Maurice Herlihy36 Hard Cases Make Bad Law This example does not mean –Every badly written paper has hidden value But some do And some well-written papers –Have little to say “The race is not always to the swift” –But the smart money bets that way …

30-Apr-15© 2014 Maurice Herlihy37 Our Mission Learn how to come up-to-speed on a research area Exact area doesn’t matter (much) –Skill is fungible You are always going to need this skill –So start now!

30-Apr-15© 2014 Maurice Herlihy38 Our Methodology Recent conference proceedings –Indicate which topics are hot –Even if the papers themselves are Incremental Cryptic Or worse!

30-Apr-15© 2014 Maurice Herlihy39 Our Methodology Recent conference proceedings –Indicate which topics are hot –Even if the papers themselves are Incremental Cryptic Or worse! Even the worst papers –Have to cite the best

30-Apr-15© 2014 Maurice Herlihy40 Detective Work Start with a recently published paper –So we know someone cares

30-Apr-15© 2014 Maurice Herlihy41 Detective Work Start with a recently published paper –So we know someone cares Skim through it & primary citations –Which citations seem important?

30-Apr-15© 2014 Maurice Herlihy42 Detective Work Start with a recently published paper –So we know someone cares Skim through it & primary citations –Which citations seem important? Identify area’s primary paper –The one to read if you read only one –First? Best improvement? Best written?

30-Apr-15© 2014 Maurice Herlihy43 Presentation (35% of Grade) Form team of 1, 2, or 3 people Pick recent paper Perform “due diligence” on area Identify one paper that everyone else –Must read first –Must submit evaluation Give presentation Repeat as needed …

30-Apr-15© 2014 Maurice Herlihy44 Your Presentation Defines problem Establishes background Identifies primary paper Leads discussion Identifies open research questions

30-Apr-15© 2014 Maurice Herlihy45 Participation (10% of Grade) Research papers sometimes –Are poorly written, –Make exaggerated or misleading claims –Contain errors or ambiguities (imagine that!). I expect students to speak up –Ask questions –Make observations –Apply critical scrutiny. It’s no fun without the studio audience!

30-Apr-15© 2014 Maurice Herlihy46 Paper Evaluations (10% of grade) Your name & paper name Summarize the paper –no more than five sentences Strengths –no more than three, one sentence each Weaknesses –no more than three, one sentence each Open problems or issues –no more than three sentences

30-Apr-15© 2014 Maurice Herlihy47 Paper Evaluations (10% of grade) Evaluations –will be graded on a scale of 1 to 3. –Default grade is 2. –Insightful reviews get 3 –Disappointing reviews get 1..

30-Apr-15© 2014 Maurice Herlihy48 Paper Evaluations (10% of grade) Mail evaluations to instructor before start of class in which the paper is presented. Late or incomplete evaluations get no credit. Must evaluate at least 2/3 of papers presented.

30-Apr-15© 2014 Maurice Herlihy49 Presentation Evaluations (10% of grade) Presenter name(s) Vision: –did presenter explain why it matters? Style: –did presenter make eye contact, mumble, etc? Exposition –confusing slides? Q&A –How were questions handled?

30-Apr-15© 2014 Maurice Herlihy50 Presentation Evaluations (10% of grade) Send evaluations to instructor –before Friday 5:00 PM in the week in which the presentation occurred. No exceptions. –must do 2/3 of presentations Be frank, but polite. Instructor will anonymize and send to presenters Exception: –no need to evaluate instructor’s presentations –too hard to anonymize

30-Apr-15© 2014 Maurice Herlihy51 Project (30% of grade) Requirements same as presentation, except that you: –Work alone, not in a team –Write a term paper, not a presentation. Consult the instructor!