Distributed Computing and Systems Philippas Tsigas Distributed Systems II TDA297(CTH), DIT290(GU) Introduction & Overview

About Us 2 Philippas Tsigas Phone: Room: 5106

3 About Us, the TAs – Ioannis Nikolakopoulos Phone: Room: 5107 – Ivan Walulya Phone: Room: 5107 – Aras Atalar Room: 5119 – Office hours: To be announced

WHY DISTRIBUTED SYSTEMS? LET’S HAVE A LOOK AT THE EVOLUTION OF COMPUTER SYSTEMS

Is this a Computer?

A modern automobile contains ECUs and this number is increasing.

Is this a Computer?

Copyright – Facebook.com Using skin to transmit information Jul 1st 2004 From The Economist print edition IT SOUNDS like an April Fool's Day joke, but it isn't. Microsoft, that imperialist of the information-technology world, has actually succeeded in patenting the human body as a computer network. US Patent 6,754,472, issued to the company on June 22nd, is for a method and apparatus for transmitting power and data using the human body.… Using skin to transmit information Jul 1st 2004 From The Economist print edition IT SOUNDS like an April Fool's Day joke, but it isn't. Microsoft, that imperialist of the information-technology world, has actually succeeded in patenting the human body as a computer network. US Patent 6,754,472, issued to the company on June 22nd, is for a method and apparatus for transmitting power and data using the human body.…

Do You Know Where Your Data Are?

Moore’s Law The Future is Distributed Bell’s Law – New computing class every 10 years year log (people per computer)

WHAT DOES INDUSTRY PROJECT? 13

14 Tomorrow? 14 Today 2020: More than 50 Billion connected devices (Ericsson)

15 Tomorrow? 15 Today 2020: More than 50 Billion connected devices (Ericsson)

Tomorrow? Distributed Systems touch all aspects of daily life! – Integral building block for our networked society 16

WHAT DOES SOCIETY NEED? 17

Rapidly growing interest in distributed systems –An alternative model for the provision of socially critical resources related fundamental services: transportation, energy, water, etc Distributed Systems This is occurring in response to a deepening awareness of the vulnerability of these services to the challenges, such as: climate change (i.e., greenhouse gas emissions) resource scarcity (e.g., fossil fuel) This is occurring in response to a deepening awareness of the vulnerability of these services to the challenges, such as: climate change (i.e., greenhouse gas emissions) resource scarcity (e.g., fossil fuel)

Rapidly growing interest in distributed systems –An alternative model for the provision of socially critical resources related fundamental services: transportation, energy, water, etc – Simultaneously there is an increasing understanding of how localised and networked systems can act as a catalyst for social innovation, social connectedness, citizen engagement and community resilience Distributed Systems These are all lessons that were learned from the unforeseen development of the Internet!

Vehicular systems are distributed systems Transportation can dramatically improve via distributed coordination

Vehicular systems are expected to gear vehicles with autopilot capabilities, improve safety, reduce energy consumption, lessen CO 2 omission… Currently, these solutions are not allowed to operate on public roads, as the risk of causing severe damage cannot be excluded with sufficient certainty

Inherently Uncertain Environment Highly Available Complex Control Sensors Control Environment User Communications How can we affordably validate the safety properties of future large- scale vehicular systems?

- The electricity grid facilitated the innovations of the 20th century -The SmartGrid is to support the green advances of the 21st. Without it, much of the other green technology cannot work The SmartGrid is a Distributed System

24 The SmartGrid is a Distributed System 24 improve and protect these systems through: adaptive coordination for distribution/allocation => energy- efficiency: e.g. microgrids, virtual powerplants

THE COURSE STRUCTURE 25

Reading 5th Edition of the book: "Distributed Systems: Concepts and Design" – written by: George Coulouris, Jean Dollimore and Tim Kindberg, Gordon Blair – published by Addison-Wesley, ISBN Some extra material: Distributed Algorithms (Notes) + papers.

Description Distributed systems are popular and powerful computing paradigms. Their importance increases as networked computers become more common than freestanding ones, especially since many different types of computers can be found in networks. In this course we will see the points of inherent difference and strength of distributed systems compared with sequential or strongly-coupled systems; consequently, we will also study the issues and problems that have to be addressed and solved efficiently for these differences to be taken advantage of, so that the system retains its strength and high potential.

Course Goals 1.Replication; The advantages and costs of replicating data: – Potential improvement in response times and reliability – Extra communication costs involved in keeping data consistent. 2.Fault-tolerant Agreement in Distributed Systems: – (a very special and significant problem, since it is a key issue in most synchronisation and coordination problems in distributed systems) – Study of the basic impossibility results and discuss their implications – Proceed with solutions and protocols for systems with certain strengths and design structures.

Goals cont. 3. Resource Allocation: Scalable and Fault-tolerant (Local) Resource Allocation 4. Distributed algorithms: How to design and analyse distributed algorithms? 5. Sensor Networks: Energy issues

Course Goals in a Nutshell Lectures: Teach you to analyze and understand how Basic Components of Distributed Systems work. Labs: Give you hands-on experience – Feel the challenges – Master the techniques Have some fun! – Optional: you can pass this course without 30

Approximate Course Schedule

32

Resources Course Homepage sv/publicPage.do?item= sv/publicPage.do?item= Slides: At homepage after lecture Last years slides available, use them as a reference point before the lecture: sv/publicPage.do?item= sv/publicPage.do?item= Full support page for the Coulouris’ book:

Labs 1st Assignment: Distributed bulletin board URL from the previous year: g-sv/publicPage.do?item= New page coming up soon

Labs cont(2). 2nd Assignment: Reliable and ordered multicast g-sv/publicPage.do?item= nd Assignment: Routing in Sensor Networks g-sv/publicPage.do?item=

Homework assignment (Optional) You will get up to 5 extra points for the exam depending on the quality of your work Select a paper related to one of the specified topics, write a report of 2-3 pages and present it in minutes (including 5 minutes of discussion) The report and presentations include the explanation of main ideas in the paper together with some background information 36

To Pass Pass all 3 labs tasks – Not graded – 2 students per group, if possible Pass written exam – Graded (extra points from the Homework assignment) 38

Lectures: Please Come to Class Lectures deepen and discuss – Difficult to do from just slides or book This is key! – Ask questions Do not be shy In general – Statistically shown: People who come to class have Better grades A higher probability of passing 39

Labs: Deadlines Submission: submit your final solution – Each submission will be graded: pass / no pass – Feedback: At the “Assignment Lectures: … + Questions and answers for all labs.” 40

41 Questions?