Microservice Architecture: Aligning Principles, Practices, and Culture

Total Page:16

File Type:pdf, Size:1020Kb

Microservice Architecture: Aligning Principles, Practices, and Culture Compliments of Microservice A r c h i t e c t u r e ALIGNING PRINCIPLES, PRACTICES, AND CULTUREIrakli Nadareishvili, Ronnie Mitra, Matt McLarty & Mike Amundsen Praise for Microservice Architecture The authors’ approach of starting with a value proposition, “Speed and Safety at Scale and in Harmony,” and reasoning from there, is an important contribution to thinking about application design. —Mel Conway, Educator and Inventor A well-thought-out and well-written description of the organizing principles underlying the microservices architectural style with a pragmatic example of applying them in practice. —James Lewis, Principal Consultant, ThoughtWorks This book demystifies one of the most important new tools for building robust, scalable software systems at speed. —Otto Berkes, Chief Technology Officer, CA Technologies If you’ve heard of companies doing microservices and want to learn more, Microservice Architecture is a great place to start. It addresses common questions and concerns about breaking down a monolith and the challenges you’ll face with culture, practices, and tooling. The microservices topic is a big one and this book gives you smart pointers on where to go next. —Chris Munns, Business Development Manager—DevOps, Amazon Web Services Anyone who is building a platform for use inside or outside an organization should read this book. It provides enough “a-ha” insights to keep everyone on your team engaged, from the business sponsor to the most technical team member. Highly recommended! —Dave Goldberg, Director, API Products, Capital One A practical roadmap to microservices design and the underlying cultural and organizational change that is needed to make it happen successfully. —Mark Boyd, Writer/Analyst, Platformable An essential guidebook for your microservices journey, presenting the concepts, discussions, and structures supportive of this architectural pattern as well as the pragmatic ground work to become successful. —Ian Kelly, Experimenter and Contributor, CA Technologies Microservice Architecture Aligning Principles, Practices, and Culture Irakli Nadareishvili, Ronnie Mitra, Matt McLarty, and Mike Amundsen Beijing Boston Farnham Sebastopol Tokyo Microservice Architecture by Irakli Nadareishvili, Ronnie Mitra, Matt McLarty, and Mike Amundsen Copyright © 2016 Mike Amundsen, Matt McLarty, Ronnie Mitra, Irakli Nadareishvili. All rights reserved. Printed in the United States of America. Published by O’Reilly Media, Inc., 1005 Gravenstein Highway North, Sebastopol, CA 95472. O’Reilly books may be purchased for educational, business, or sales promotional use. Online editions are also available for most titles (http://safaribooksonline.com). For more information, contact our corporate/ institutional sales department: 800-998-9938 or [email protected] . Editors: Brian MacDonald and Holly Bauer Indexer: WordCo Indexing Services, Inc. Production Editor: Kristen Brown Interior Designer: David Futato Copyeditor: Christina Edwards Cover Designer: Karen Montgomery Proofreader: Kim Cofer Illustrator: Melanie Yarbrough June 2016: First Edition Revision History for the First Edition 2016-06-02: First Release See http://oreilly.com/catalog/errata.csp?isbn=9781491956250 for release details. The O’Reilly logo is a registered trademark of O’Reilly Media, Inc. Microservice Architecture, the cover image, and related trade dress are trademarks of O’Reilly Media, Inc. While the publisher and the authors have used good faith efforts to ensure that the information and instructions contained in this work are accurate, the publisher and the authors disclaim all responsibility for errors or omissions, including without limitation responsibility for damages resulting from the use of or reliance on this work. Use of the information and instructions contained in this work is at your own risk. If any code samples or other technology this work contains or describes is subject to open source licenses or the intellectual property rights of others, it is your responsibility to ensure that your use thereof complies with such licenses and/or rights. 978-1-491-95979-4 [LSI] Table of Contents Preface. xi Part I. Understanding Microservices 1. The Microservices Way. 3 Understanding Microservices 4 Adopting Microservices 5 “What are microservices? Don’t I already have them?” 6 “How could this work here?” 7 “How would we deal with all the parts? Who is in charge?” 8 The Microservices Way 9 The Speed of Change 9 The Safety of Change 9 At Scale 10 In Harmony 10 Summary 11 2. The Microservices Value Proposition. 13 Microservice Architecture Benefits 13 Deriving Business Value 15 Defining a Goal-Oriented, Layered Approach 17 Modularized Microservice Architecture 17 Cohesive Microservice Architecture 18 Systematized Microservice Architecture 18 Maturity Model for Microservice Architecture Goals and Benefits 19 Applying the Goal-Oriented, Layered Approach 20 Summary 21 vii Part II. Microservice Design Principles 3. Designing Microservice Systems. 25 The Systems Approach to Microservices 25 Service 27 Solution 28 Process and Tools 28 Organization 28 Culture 29 Embracing Change 29 Putting it Together: The Holistic System 30 Standardization and Coordination 30 A Microservices Design Process 33 Set Optimization Goals 34 Development Principles 35 Sketch the System Design 35 Implement, Observe, and Adjust 36 The Microservices System Designer 38 Summary 38 4. Establishing a Foundation. 41 Goals and Principles 42 Goals for the Microservices Way 42 Operating Principles 45 Platforms 49 Shared Capabilities 50 Local Capabilities 52 Culture 54 Focus on Communication 55 Aligning Your Teams 55 Fostering Innovation 56 Summary 58 Part III. Microservices in Practice 5. Service Design. 61 Microservice Boundaries 62 Microservice Boundaries and Domain-Driven Design 62 Bounded Context 64 Smaller Is Better 65 Ubiquitous Language 66 viii | Table of Contents API Design for Microservices 67 Messsage-Oriented 67 Hypermedia-Driven 68 Data and Microservices 70 Shipping, Inc. 70 Event Sourcing 72 System Model for Shipping, Inc. 75 CQRS 76 Distributed Transactions and Sagas 78 Asynchronous Message-Passing and Microservices 80 Dealing with Dependencies 81 Pragmatic Mobility 84 Summary 86 6. System Design and Operations. 89 Independent Deployability 89 More Servers, More Servers! My Kingdom for a Server! 91 Docker and Microservices 93 The Role of Service Discovery 94 The Need for an API Gateway 97 Security 97 Transformation and Orchestration 98 Routing 100 Monitoring and Alerting 101 Summary 101 7. Adopting Microservices in Practice. 103 Solution Architecture Guidance 104 How many bug fixes/features should be included in a single release? 104 When do I know our microservice transformation is done? 104 Organizational Guidance 105 How do I know if my organization is ready for microservices? 105 Culture Guidance 106 How do I introduce change? 106 Can I do microservices in a project-centric culture? 108 Can I do microservices with outsourced workers? 108 Tools and Process Guidance 109 What kinds of tools and technology are required for microservices? 109 What kinds of practices and processes will I need to support microservices? 110 How do I govern a microservice system? 111 Services Guidance 112 Table of Contents | ix Should all microservices be coded in the same programming language? 112 What do I do about orphaned components? 113 Summary 113 8. Epilogue. 115 A. Microservice Architecture Reading List. 117 Index. 121 x | Table of Contents Preface Microservice architecture has emerged as a common pattern of software develop‐ ment from the practices of a number of leading organizations. These practices includes principles, technologies, methodologies, organizational tendencies, and cul‐ tural characteristics. Companies taking steps to implement microservices and reap their benefits need to consider this broad scope. Who Should Read This Book You should read this book if you are interested in the architectural, organizational, and cultural changes that are needed to succeed with a microservice architecture. We primarily wrote this book for technology leaders and software architects who want to shift their organizations toward the microservices style of application development. You don’t have to be a CTO or enterprise architect to enjoy this book, but we’ve writ‐ ten our guidance under the assumption that you are able to influence the organiza‐ tional design, technology platform, and software architecture at your company. What’s In This Book This book promotes a goal-oriented, design-based approach to microservice architec‐ ture. We offer this design-centric approach because, as we talked to several companies about their programs, we discovered one of the keys to their success was the willing‐ ness to not stick to a single tool or process as they attempted to increase their compa‐ ny’s time-to-market while maintaining—even increasing—their systems’ safety and resilience. The companies we talked to offered a wide range of services including live video and audio streaming service, foundation-level virtual services in the cloud, and support for classic brick-and-mortar operations. While these companies’ products vary, we learned that the principles of speed and safety “at scale” were a common thread. They xi each worked to provide the same system properties in their own unique ways—ways that fit the key business values and goals of the company. It’s the properties and values that we focus on in this book, and the patterns and prac‐ tices we see companies employ in order to reach their unique
Recommended publications
  • Rugby - a Process Model for Continuous Software Engineering
    INSTITUT FUR¨ INFORMATIK DER TECHNISCHEN UNIVERSITAT¨ MUNCHEN¨ Forschungs- und Lehreinheit I Angewandte Softwaretechnik Rugby - A Process Model for Continuous Software Engineering Stephan Tobias Krusche Vollstandiger¨ Abdruck der von der Fakultat¨ fur¨ Informatik der Technischen Universitat¨ Munchen¨ zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.) genehmigten Dissertation. Vorsitzender: Univ.-Prof. Dr. Helmut Seidl Prufer¨ der Dissertation: 1. Univ.-Prof. Bernd Brugge,¨ Ph.D. 2. Prof. Dr. Jurgen¨ Borstler,¨ Blekinge Institute of Technology, Karlskrona, Schweden Die Dissertation wurde am 28.01.2016 bei der Technischen Universitat¨ Munchen¨ eingereicht und durch die Fakultat¨ fur¨ Informatik am 29.02.2016 angenommen. Abstract Software is developed in increasingly dynamic environments. Organizations need the capability to deal with uncertainty and to react to unexpected changes in require- ments and technologies. Agile methods already improve the flexibility towards changes and with the emergence of continuous delivery, regular feedback loops have become possible. The abilities to maintain high code quality through reviews, to regularly re- lease software, and to collect and prioritize user feedback, are necessary for con- tinuous software engineering. However, there exists no uniform process model that handles the increasing number of reviews, releases and feedback reports. In this dissertation, we describe Rugby, a process model for continuous software en- gineering that is based on a meta model, which treats development activities as parallel workflows and which allows tailoring, customization and extension. Rugby includes a change model and treats changes as events that activate workflows. It integrates re- view management, release management, and feedback management as workflows. As a consequence, Rugby handles the increasing number of reviews, releases and feedback and at the same time decreases their size and effort.
    [Show full text]
  • MAKING DATA MODELS READABLE David C
    MAKING DATA MODELS READABLE David C. Hay Essential Strategies, Inc. “Confusion and clutter are failures of [drawing] design, not attributes of information. And so the point is to find design strategies that reveal detail and complexity ¾ rather than to fault the data for an excess of complication. Or, worse, to fault viewers for a lack of understanding.” ¾ Edward R. Tufte1 Entity/relationship models (or simply “data models”) are powerful tools for analyzing and representing the structure of an organization. Properly used, they can reveal subtle relationships between elements of a business. They can also form the basis for robust and reliable data base design. Data models have gotten a bad reputation in recent years, however, as many people have found them to be more trouble to produce and less beneficial than promised. Discouraged, people have gone on to other approaches to developing systems ¾ often abandoning modeling altogether, in favor of simply starting with system design. Requirements analysis remains important, however, if systems are ultimately to do something useful for the company. And modeling ¾ especially data modeling ¾ is an essential component of requirements analysis. It is important, therefore, to try to understand why data models have been getting such a “bad rap”. Your author believes, along with Tufte, that the fault lies in the way most people design the models, not in the underlying complexity of what is being represented. An entity/relationship model has two primary objectives: First it represents the analyst’s public understanding of an enterprise, so that the ultimate consumer of a prospective computer system can be sure that the analyst got it right.
    [Show full text]
  • Agile Methods: Where Did “Agile Thinking” Come From?
    Historical Roots of Agile Methods: Where did “Agile Thinking” Come from? Noura Abbas, Andrew M Gravell, Gary B Wills School of Electronics and Computer Science, University of Southampton Southampton, SO17 1BJ, United Kingdom {na06r, amg, gbw}@ecs.soton.ac.uk Abstract. The appearance of Agile methods has been the most noticeable change to software process thinking in the last fifteen years [16], but in fact many of the “Agile ideas” have been around since 70’s or even before. Many studies and reviews have been conducted about Agile methods which ascribe their emergence as a reaction against traditional methods. In this paper, we argue that although Agile methods are new as a whole, they have strong roots in the history of software engineering. In addition to the iterative and incremental approaches that have been in use since 1957 [21], people who criticised the traditional methods suggested alternative approaches which were actually Agile ideas such as the response to change, customer involvement, and working software over documentation. The authors of this paper believe that education about the history of Agile thinking will help to develop better understanding as well as promoting the use of Agile methods. We therefore present and discuss the reasons behind the development and introduction of Agile methods, as a reaction to traditional methods, as a result of people's experience, and in particular focusing on reusing ideas from history. Keywords: Agile Methods, Software Development, Foundations and Conceptual Studies of Agile Methods. 1 Introduction Many reviews, studies and surveys have been conducted on Agile methods [1, 20, 15, 23, 38, 27, 22].
    [Show full text]
  • Alignment of Business and Application Layers of Archimate
    Alignment of Business and Application Layers of ArchiMate Oleg Svatoš1, Václav Řepa1 1Department of Information Technologies, Faculty of Informatics and Statistics, University of Economics, Prague [email protected], [email protected] Abstract. ArchiMate is widely used standard for modelling enterprise architec- ture and organizes the model in separate yet interconnected layers. Unfortunate- ly the ArchiMate specification provides us with rather brief detail on the rela- tions between the individual layers and the guidelines how to have them aligned. In this paper we focus on the alignment between business and applica- tion layers especially alignment of business processes and application functions, which we see as crucial condition for proper and consistent enterprise architec- ture. For this alignment we propose an extension for ArchiMate based on the development done in Methodology for Modelling and Analysis of Business Process (MMABP). Application of the proposed extension is illustrated on an example and its benefits discussed. Keywords: business process model·Enterprise Architec- ture·ArchiMate·TOGAF·MMABP·functional model·object life cycle 1 Introduction The enterprise architecture plays an important role in current corporate management. Enterprises realized that after the initial spontaneous growth and accumulation of dif- ferent legacy systems over the years, it is necessary to create the living organism forming an enterprise under some kind of control in order to allow managing it. The enterprise architecture is one of the tools which help them to do it. There are different frameworks for capturing the enterprise architectures like FEAF [20], DoDAF [21], ISO 19439 [22], etc. out of which the most popular standard is the TOGAF [14] accompanied by ArchiMate as the modelling language [1].
    [Show full text]
  • Fundamentals of a Discipline of Computer Program and Systems Design, Edward Yourdon, Larry L
    Structured Design: Fundamentals of a Discipline of Computer Program and Systems Design, Edward Yourdon, Larry L. Constantine, Yourdon Press, 1978, 0917072111, 9780917072116, . DOWNLOAD http://bit.ly/1gngZ6L The practical guide to structured systems design , Jones Page, Meilir Page-Jones, 1986, Computers, 354 pages. Structured programming: tutorial, Part 3 tutorial, Victor R. Basili, Terry Baker, IEEE Computer Society, 1975, Computers, 241 pages. Method integration concepts and case studies, Klaus Kronlöf, 1993, , 402 pages. Using a systematic approach, it describes the concept of method integration. Presents a detailed investigation of several major techniques, including Information Modeling .... Structured walkthroughs , Edward Yourdon, 1985, , 140 pages. A-Plus Pascal , Richard Tingey, Suzanne Loyer Antink, Feb 1, 1994, , 741 pages. Current and timely, this textbook prepares students for the College Entrance BoardUs Advanced Placement Computer Science Exam.. Structured systems development , Ken Orr, Jan 1, 1977, Computers, 170 pages. Problem solving and computer programming , Peter Grogono, Sharon H. Nelson, 1982, Mathematics, 284 pages. Problem Solving Using Pascal Algorithm Development and Programming Concepts, Romualdas Skvarcius, 1984, Computers, 673 pages. Programming logic structured design, Anne L. Topping, Ian L. Gibbons, Jan 1, 1985, Computers, 285 pages. Reliable software through composite design , Glenford J. Myers, 1975, Computers, 159 pages. Structured Programming Theory and Practice, Richard C. Linger, Jan 1, 1979, Computers, 402 pages. Precision programming. Elements of logical expression. Elements of program expression. Structured programs. Reading structured programs. The correctness of structured programs .... Manernichane musically. Impartial analysis any creative act shows that the whole image causes catharsis, thus, all the listed signs of an archetype and myth confirm that the action mechanisms myth-making mechanisms akin artistic and productive thinking.
    [Show full text]
  • Chapter 1: Introduction
    Just Enough Structured Analysis Chapter 1: Introduction “The beginnings and endings of all human undertakings are untidy, the building of a house, the writing of a novel, the demolition of a bridge, and, eminently, the finish of a voyage.” — John Galsworthy Over the River, 1933 www.yourdon.com ©2006 Ed Yourdon - rev. 051406 In this chapter, you will learn: 1. Why systems analysis is interesting; 2. Why systems analysis is more difficult than programming; and 3. Why it is important to be familiar with systems analysis. Chances are that you groaned when you first picked up this book, seeing how heavy and thick it was. The prospect of reading such a long, technical book is enough to make anyone gloomy; fortunately, just as long journeys take place one day at a time, and ultimately one step at a time, so long books get read one chapter at a time, and ultimately one sentence at a time. 1.1 Why is systems analysis interesting? Long books are often dull; fortunately, the subject matter of this book — systems analysis — is interesting. In fact, systems analysis is more interesting than anything I know, with the possible exception of sex and some rare vintages of Australian wine. Without a doubt, it is more interesting than computer programming (not that programming is dull) because it involves studying the interactions of people, and disparate groups of people, and computers and organizations. As Tom DeMarco said in his delightful book, Structured Analysis and Systems Specification (DeMarco, 1978), [systems] analysis is frustrating, full of complex interpersonal relationships, indefinite, and difficult.
    [Show full text]
  • Edward Yourdon
    EDWARD YOURDON EDWARD YOURDON is an internationally-recognized computer consultant, as well as the author of more than two dozen books, including Byte Wars, Managing High-Intensity Internet Projects, Death March, Rise and Resurrection of the American Programmer, and Decline and Fall of the American Programmer. His latest book, Outsource: competing in the global productivity race, discusses both current and future trends in offshore outsourcing, and provides practical strategies for individuals, small businesses, and the nation to cope with this unstoppable tidal wave. According to the December 1999 issue of Crosstalk: The Journal of Defense Software Engineering, Ed Yourdon is one of the ten most influential men and women in the software field. In June 1997, he was inducted into the Computer Hall of Fame, along with such notables as Charles Babbage, Seymour Cray, James Martin, Grace Hopper, Gerald Weinberg, and Bill Gates. Ed is widely known as the lead developer of the structured analysis/design methods of the 1970s, as well as a co-developer of the Yourdon/Whitehead method of object-oriented analysis/design and the Coad/Yourdon OO methodology in the late 1980s and 1990s. He was awarded a Certificate of Merit by the Second International Workshop on Computer-Aided Software Engineering in 1988, for his contributions to the promotion of Structured Methods for the improvement of Information Systems Development, leading to the CASE field. He was selected as an Honored Member of Who’s Who in the Computer Industry in 1989. And he was given the Productivity Award in 1992 by Computer Language magazine, for his book Decline and Fall of the American Programmer.
    [Show full text]
  • Death March Projects Ed Yourdon Email: [email protected] Web: Blog
    Death March projects Ed Yourdon email: [email protected] web: http://www.yourdon.com blog: http://www.yourdon.com/blog JaSST keynote presentation January 30, 2007 What is a “death-march” project? Origin: "extreme" sports, ultra-marathon, triathlons, etc. Sometimes known as "death- march" projects Almost always: Significant schedule pressure -- project must be finished in far less than "nominal" time. Often: Staffing shortages -- project must be done with significantly fewer people than in a "normal" project Sometimes: budget limitations -- inadequate funding to pay for people, development tools, and other resources. Inevitably: greater risks (>50% chance of failure), more pressure, unpleasant politics Almost always: heavy overtime (more than just 10-20% extra effort), personal sacrifices, increased burnout, higher turnover, lower productivity, lower quality Increasingly often: significant corporate consequences (e.g., bankruptcy), lawsuits, personal legal liabilities Copyright © 2007 by Edward Yourdon 2 Your next assignment “Give me an estimate for the XYZ system. I think it will take… 6 months 5 people ¥2,500,000 I need the estimate by the end of the day.” Copyright © 2007 by Edward Yourdon 3 Your assessment I think it will take… 12 months 10 people ¥10,000,000 …but I really need more time for a careful estimate!” Question for discussion: what if this scenario occurs on every project? Copyright © 2007 by Edward Yourdon 4 INTRODUCTION : What’s so different about death-march projects? Users and managers are becoming ever more demanding. Many of today's projects are defined as “mission-critical” Many "extreme" projects require BPR to succeed -- just like the early days of client-server projects, during which we learned that 80% of BPR projects were failures.
    [Show full text]
  • Part I the Scrum Guide
    Senior Project - Part I CSc 190-01 (Seminar 32218) Tu 8:00 to 8:50 AM, Benicia Hall 1025 CSc 190-04 (Seminar 32545) Tu 9:00 to 9:50 AM, Benicia Hall 1025 Spring Semester 2018 Course Instructor: Professor Buckley Office Hours Office: Riverside Hall 3002 Time TBD Phone: (916) 278- 7324 or by appointment Email: [email protected] Required Prerequisites: Senior status (90 units completed) WPJ score of 70+, or at least a C- in ENGL 109M/W Courses completed: CSc 130, CSc 131, and four additional 3-unit CSc upper division courses that fulfill the major requirements (excluding CSC 192-195, CSC 198, CSC 199) Catalog Description: The first of a two-course sequence in which student teams undertake a project to develop and deliver a software product. Approved project sponsors must be from industry, government, a non-profit organization, or other area. Teams apply software engineering principles in the preparation of a software proposal, a project management plan and a software requirements specification. All technical work is published using guidelines modeled after IEEE documentation standards. Oral and written reports are required. Lecture one hour, laboratory three hours. 2 Units Required Text: SCRUM: A Breathtakingly Brief and Agile Introduction, Chris Sims & Louise Johnson, Dymaxicon ©2012 (If not in the bookstore, available from Amazon) Required Text (link to document is on the Course website): The Scrum Guide: The Definitive Guide to Scrum: The Rules of the Game Jeff Sutherland & Ken Schwaber, July 2017 READINGS (links available on course website): Agile Manifesto and Guiding Principles Establishing Self-Organized Agile Teams Self-organizing Scrum teams – Challenges and Strategies Collaboration Skills for Agile Teams Use cases versus user stories in Agile development Death March, Edward Yourdon (excerpt) “You can’t make teams jell.
    [Show full text]
  • Tool Support for Risk-Driven Planning of Trustworthy Smart Iot Systems Within Devops
    Tool support for risk-driven planning of trustworthy smart IoT systems within DevOps Andreas Thompson Thesis submitted for the degree of Master in Informatics: programming and networks 60 credits Department of Informatics Faculty of mathematics and natural sciences UNIVERSITY OF OSLO Autumn 2019 Tool support for risk-driven planning of trustworthy smart IoT systems within DevOps Andreas Thompson © 2019 Andreas Thompson Tool support for risk-driven planning of trustworthy smart IoT systems within DevOps http://www.duo.uio.no/ Printed: Reprosentralen, University of Oslo Abstract The Internet of Things is rising in popularity across many different domains, such as build automation, healthcare, electrical smart metering and physical security. Many prominent IT experts and companies like Gartner expect there to be a continued rise in the amount of IoT endpoints, with an estimated 5.8 million endpoints in 2020. With the rapid growth of the devices, the physical nature of these devices, and the amount of data collected, there will be a greater need for trustworthiness. These devices often gather personal data and as the devices have relatively less computational power than other devices, security and privacy risks are greater. With the IoT systems often operating in highly dynamic environments, the development of these systems should often be done in an iterative manner. De- vOps is an increasingly popular agile practice which combines the development and operations of systems to provide continuous delivery. This is well suited for the development of IoT systems. However, there is currently a lack of support for risk driven planning of trust- worthy smart IoT systems within DevOps.
    [Show full text]
  • Death March by Ed Yourdon
    Death-March Projects ICSE conference — May 20, 1997 [email protected] http://www.yourdon.com An informal survey N In general, our projects are: N Under budget and ahead of schedule N About 10% over budget, 10% behind schedule N About 50-100% over budget, 50-100% behind schedule N Substantially more than 100% over budget, 100% behind schedule Copyright © 1996 by Edward Yourdon 2 Death-March definitions N Definition 1: Project parameters exceed the norm by >50% 3 Schedule compression (most common) 3 Staff reduction 3 Budget/resource constraints 3 Functionality/performance demands N Definition 2: risk assessment (technical, legal, political, etc.) indicates >50% chance of failure N Observation: this is now the norm, not the exception Copyright © 1996 by Edward Yourdon 3 Different kinds of Death- March projects N Small-scale: 3-6 people for 3-6 months N Large-scale: 100-200 people for 3-5 years N Mind-boggling: 1,000 - 2,000 people for 7-10 years Copyright © 1996 by Edward Yourdon 4 Why Do Death-March Projects Occur? N The technical answer: we’re dumb 3We don’t practice software engineering 3We don’t use the right methods and tools 3We don’t know how to estimate our projects N The “don’t blame us” answer: 3it’s all the fault of Machiavellian managers 3Managers are evil, and they cunningly force us to take on 12-month projects with a 6-month deadline N The sobering reality: whatever the reason, this has now become the “norm,” not the exception Copyright © 1996 by Edward Yourdon 5 Why Do Death-Marches Occur? N Politics, politics, politics N Naive promises made by marketing, senior executives, project managers, etc.
    [Show full text]
  • LOG6306 : Études Empiriques Sur Les Patrons Logiciels
    LOG6306 : Études empiriques sur les patrons logiciels Yann-Gaël Guéhéneuc Recurring Course – Well-known Computer Scientists Département de génie informatique et de génie logiciel École Polytechnique de Montréal © Guéhéneuc, 2012 Why Is It Important? (1/2) Those who cannot remember the past are condemned to repeat it. – By George Santayana – Life of Reason, Reason in Common Sense, Scribner's, 1905, page 284 2/52 Why Is It Important? (2/2) Pythagoras theorem Euclid’s theorem Intercept theorem or Thales’ theorem … You know the Nobel Prizes… … do you know the Turing Awards? 3/52 Some Known Computer Scientists Frances E. Allen Grady Booch Frederick Brooks Ole -Johan Dahl et Kristen Nygaard Erich Gamma Grace Murray Hopper Manny Lehman Barbara Liskov John McCarthy Dave Parnas Edward Yourdon 4/52 Frances E. Allen Frances E. Allen Frances E. Allen – Born on the 4th of August, 1932 *1932 – Pioneer of optimising compilation, code optimisation, and parallelisation AWC Augusta Ada Lovelace Award en 2002 ACM Turing Award en 2006 – Cf. http://en.wikipedia.org/wiki/Frances_E._Allen 5/52 Frances E. Allen Before 1966 – Since the 1930s • Programmable computers – Since the 1950s • First compilers by Grace Murray Hopper • Programming languages – FORTRAN: first complete compiler – COBOL: first programming language compiled for different computer architectures (UNIVAC II et RCA 501) 6/52 Frances E. Allen Before 1966 – In 1955 • Context-free grammar invented by Noam Chomsky – In 1966 • LR Parsing invented by Donald Knuth 7/52 Frances E. Allen In 1966 – Program Optimization • Use of graphs to describe programs and to allow their optimisations In 1970 – Control Flow Analysis et A Basis for Program Optimization • Intervals for control-flow analyses In 1974 – Interprocedural data flow analysis • Interprocedural analyses of whole programs 8/52 Grady Booch Grady Booch Grady Booch – Born 27 February 1955 *1955 – Father of the UML with Jacobson et Rumbaugh Stevens Award in 2003 – Cf.
    [Show full text]