Learn Microservices with Spring Boot

Total Page:16

File Type:pdf, Size:1020Kb

Learn Microservices with Spring Boot Learn Microservices with Spring Boot A Practical Approach to RESTful Services using RabbitMQ, Eureka, Ribbon, Zuul and Cucumber — Moises Macero Learn Microservices with Spring Boot A Practical Approach to RESTful Services using RabbitMQ, Eureka, Ribbon, Zuul and Cucumber Moises Macero Learn Microservices with Spring Boot: A Practical Approach to RESTful Services using RabbitMQ, Eureka, Ribbon, Zuul and Cucumber Moises Macero New York, USA ISBN-13 (pbk): 978-1-4842-3164-7 ISBN-13 (electronic): 978-1-4842-3165-4 https://doi.org/10.1007/978-1-4842-3165-4 Library of Congress Control Number: 2017962334 Copyright © 2017 by Moises Macero This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Trademarked names, logos, and images may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, logo, or image we use the names, logos, and images only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. Cover image by Freepik (www.freepik.com) Managing Director: Welmoed Spahr Editorial Director: Todd Green Acquisitions Editor: Steve Anglin Development Editor: Matthew Moodie Technical Reviewer: Manuel Jordan Elera Coordinating Editor: Mark Powers Copy Editor: Kezia Endsley Distributed to the book trade worldwide by Springer Science+Business Media New York, 233 Spring Street, 6th Floor, New York, NY 10013. Phone 1-800-SPRINGER, fax (201) 348-4505, e-mail [email protected], or visit www.springeronline.com. Apress Media, LLC is a California LLC and the sole member (owner) is Springer Science + Business Media Finance Inc (SSBM Finance Inc). SSBM Finance Inc is a Delaware corporation. For information on translations, please e-mail [email protected], or visit http://www.apress.com/rights-permissions. Apress titles may be purchased in bulk for academic, corporate, or promotional use. eBook versions and licenses are also available for most titles. For more information, reference our Print and eBook Bulk Sales web page at http://www.apress.com/bulk-sales. Any source code or other supplementary material referenced by the author in this book is available to readers on GitHub via the book’s product page, located at www.apress.com/ 9781484231647. For more detailed information, please visit http://www.apress.com/ source-code. Printed on acid-free paper Table of Contents About the Author ���������������������������������������������������������������������������������ix About the Technical Reviewer �������������������������������������������������������������xi Chapter 1: Introduction ������������������������������������������������������������������������1 Setting the Scene ��������������������������������������������������������������������������������������������������1 Who Are You? ��������������������������������������������������������������������������������������������������������2 How Is This Book Different from Other Books and Guides? ����������������������������������3 Reasoning Behind the Techniques ������������������������������������������������������������������3 Learning: An Incremental Process �������������������������������������������������������������������4 Is This a Guide or a Book? �������������������������������������������������������������������������������4 Contents ����������������������������������������������������������������������������������������������������������������5 From the Basics to Advanced Topics ���������������������������������������������������������������5 Skeleton with Spring Boot, the Professional Way ��������������������������������������������5 Test-Driven Development ��������������������������������������������������������������������������������6 Connecting Microservices �������������������������������������������������������������������������������6 Event-Driven System ���������������������������������������������������������������������������������������6 End-to-End Testing ������������������������������������������������������������������������������������������7 Summary ��������������������������������������������������������������������������������������������������������������7 iii TABLE OF CONtENtS Chapter 2: The Basic Spring Boot Application ��������������������������������������9 Business Requirements ����������������������������������������������������������������������������������������9 The Skeleton App ������������������������������������������������������������������������������������������������10 Skinny vs. Real-Life Apps ������������������������������������������������������������������������������10 Creating the Skeleton ������������������������������������������������������������������������������������11 Warming Up: Some TDD in Action �����������������������������������������������������������������������13 Summary ������������������������������������������������������������������������������������������������������������21 Chapter 3: A Real Three-­Tier Spring Boot Application ������������������������23 Introduction ���������������������������������������������������������������������������������������������������������23 Completing the Basics ����������������������������������������������������������������������������������������26 Designing the Domain �����������������������������������������������������������������������������������������33 The Business Logic Layer �����������������������������������������������������������������������������������38 The Presentation Layer (REST API) ����������������������������������������������������������������������41 The Multiplication Controller �������������������������������������������������������������������������43 The Results Controller �����������������������������������������������������������������������������������48 The Frontend (Web Client) �����������������������������������������������������������������������������������53 Playing with the Application (Part I) ��������������������������������������������������������������������58 New Requirements for Data Persistence ������������������������������������������������������������59 Refactoring the Code ������������������������������������������������������������������������������������������63 The Data Layer ����������������������������������������������������������������������������������������������������68 The Data Model ���������������������������������������������������������������������������������������������71 The Repositories ��������������������������������������������������������������������������������������������77 Completing User Story 2: Going Through the Layers ������������������������������������������87 Playing with the Application (Part II) �������������������������������������������������������������������94 Summary ������������������������������������������������������������������������������������������������������������97 iv TABLE OF CONtENtS Chapter 4: Starting with Microservices ����������������������������������������������99 The Small Monolith Approach �����������������������������������������������������������������������������99 Analyzing the Monolith ��������������������������������������������������������������������������������103 Moving Forward �������������������������������������������������������������������������������������������105 Gamification Basics ������������������������������������������������������������������������������������������106 Points, Badges, and Leaderboards ��������������������������������������������������������������106 Applying It to the Example ���������������������������������������������������������������������������107 Moving to a Microservices Architecture ������������������������������������������������������������108 Separation of Concerns and Loose Coupling �����������������������������������������������108 Independent Changes ����������������������������������������������������������������������������������109 Scalability ����������������������������������������������������������������������������������������������������109 Connecting Microservices ���������������������������������������������������������������������������������110 Event-Driven Architecture ���������������������������������������������������������������������������������112 Related Techniques �������������������������������������������������������������������������������������113 Pros and Cons of Event-Driven Architecture �����������������������������������������������114 Further Reading �������������������������������������������������������������������������������������������117
Recommended publications
  • From Zero to 1000 Tests in 6 Months
    From Zero to 1000 tests in 6 months Or how not to lose your mind with 2 week iterations Name is Max Vasilyev Senior Developer and QA Manager at Solutions Aberdeen http://tech.trailmax.info @trailmax Business Does Not Care • Business does not care about tests. • Business does not care about internal software quality. • Business does not care about architecture. • Some businesses don’t care so much, they even don’t care about money. Don’t Tell The Business Just do it! Just write your tests, ask no one. Honestly, tomorrow in the office just create new project, add NUnit package and write a test. That’ll take you 10 minutes. Simple? Writing a test is simple. Writing a good test is hard. Main questions are: – What do you test? – Why do you test? – How do you test? Our Journey: Stone Age Started with Selenium browser tests: • Recording tool is OK to get started • Boss loved it! • Things fly about on the screen - very dramatic But: • High maintenance effort • Problematic to check business logic Our Journey: Iron Age After initial Selenium fever, moved on to integration tests: • Hook database into tests and part-test database. But: • Very difficult to set up (data + infrastructure) • Problematic to test logic Our Journey: Our Days • Now no Selenium tests • A handful of integration tests • Most of the tests are unit-ish* tests • 150K lines of code in the project • Around 1200 tests with 30% coverage** • Tests are run in build server * Discuss Unit vs Non-Unit tests later ** Roughly 1 line of test code covers 2 lines of production code Testing Triangle GUI Tests GUI Tests Integration Tests Integration Tests Unit Tests Unit Tests Our Journey: 2 Week Iterations? The team realised tests are not optional after first 2-week iteration: • There simply was no time to manually test everything at the end of iteration.
    [Show full text]
  • Designpatternsphp Documentation Release 1.0
    DesignPatternsPHP Documentation Release 1.0 Dominik Liebler and contributors Jul 18, 2021 Contents 1 Patterns 3 1.1 Creational................................................3 1.1.1 Abstract Factory........................................3 1.1.2 Builder.............................................8 1.1.3 Factory Method......................................... 13 1.1.4 Pool............................................... 18 1.1.5 Prototype............................................ 21 1.1.6 Simple Factory......................................... 24 1.1.7 Singleton............................................ 26 1.1.8 Static Factory.......................................... 28 1.2 Structural................................................. 30 1.2.1 Adapter / Wrapper....................................... 31 1.2.2 Bridge.............................................. 35 1.2.3 Composite............................................ 39 1.2.4 Data Mapper.......................................... 42 1.2.5 Decorator............................................ 46 1.2.6 Dependency Injection...................................... 50 1.2.7 Facade.............................................. 53 1.2.8 Fluent Interface......................................... 56 1.2.9 Flyweight............................................ 59 1.2.10 Proxy.............................................. 62 1.2.11 Registry............................................. 66 1.3 Behavioral................................................ 69 1.3.1 Chain Of Responsibilities...................................
    [Show full text]
  • An Empirical Study on the Practice of Maintaining Object-Relational Mapping Code in Java Systems
    An Empirical Study on the Practice of Maintaining Object-Relational Mapping Code in Java Systems Tse-Hsun Chen Weiyi Shang Jinqiu Yang Queen’s University Concordia University University of Waterloo Ontario, Canada Quebec, Canada Ontario, Canada [email protected] [email protected] [email protected] Ahmed E. Hassan Michael W. Godfrey Queen’s University University of Waterloo Ontario, Canada Ontario, Canada [email protected] [email protected] Mohamed Nasser Parminder Flora BlackBerry BlackBerry Ontario, Canada Ontario, Canada ABSTRACT code. Future studies should carefully examine ORM code, Databases have become one of the most important compo- in particular given the rising use of ORM in modern software nents in modern software systems. For example, web ser- systems. vices, cloud computing systems, and online transaction pro- cessing systems all rely heavily on databases. To abstract 1. INTRODUCTION the complexity of accessing a database, developers make use Managing data consistency between source code and database of Object-Relational Mapping (ORM) frameworks. ORM is a difficult task, especially for complex large-scale systems. frameworks provide an abstraction layer between the appli- As more systems become heavily dependent on databases, it cation logic and the underlying database. Such abstraction is important to abstract the database accesses from devel- layer automatically maps objects in Object-Oriented Lan- opers. Hence, developers nowadays commonly make use of guages to database records, which significantly reduces the Object-Relation Mapping (ORM) frameworks to provide a amount of boilerplate code that needs to be written. conceptual abstraction between objects in Object-Oriented Despite the advantages of using ORM frameworks, we ob- Languages and data records in the underlying database.
    [Show full text]
  • Stream-Based Verification with Junit
    Stream-Based Verification with JUnit Strombasierte Verifikation mit JUnit Masterarbeit Im Rahmen des Studiengangs Vorgelegt von Ausgegeben und betreut von Informatik Denis-Michael Lux Prof. Dr. Martin Leucker der Universität zu Lübeck mit Unterstützung von Malte Schmitz, M.Sc. Dipl.-Inf. Daniel Thoma Lübeck, den 14. Juni 2019 Selbstständigkeitserklärung Der Verfasser versichert an Eides statt, dass er die vorliegende Arbeit selbständig, ohne fremde Hilfe und ohne Benutzung anderer als der angegebenen Hilfsmittel angefertigt hat. Die aus fremden Quellen (einschließlich elektronischer Quellen) direkt oder indirekt über- nommenen Gedanken sind ausnahmslos als solche kenntlich gemacht. Die Arbeit ist in gle- icher oder ähnlicher Form oder auszugsweise im Rahmen einer anderen Prüfung noch nicht vorgelegt worden. Ort/Datum Unterschrift des Verfassers Contents Introduction 1 1 Unit Testing and Mocking in JUnit 3 1.1 Unit Testing ................................... 4 1.2 The JUnit Testing Framework ......................... 4 1.3 Assertions .................................... 8 1.4 Mocks and Stubs ................................ 10 2 Stream Runtime Verification 13 2.1 Runtime Verfication .............................. 13 2.2 Stream Processing ............................... 14 2.3 Temporal Stream-based Specification Language (TeSSLa) .......... 20 3 TeSSLa-Based Monitoring and Mocking in JUnit 25 3.1 Application Code Instrumentation ...................... 25 3.2 Monitors for Test Cases and Test Suites .................... 28 3.3 Class and Interface
    [Show full text]
  • Autonomic Test Case Generation of Failing Code Using AOP By
    Autonomic Test Case Generation of Failing Code Using AOP by Giovanni Murguia B.Sc., Instituto Tecnol´ogicoy de Estudios Superiores de Monterrey, Mexico 2008 A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in the Department of Computer Science c Giovanni Murguia, 2020 University of Victoria All rights reserved. This thesis may not be reproduced in whole or in part, by photocopying or other means, without the permission of the author. ii Autonomic Test Case Generation of Failing Code Using AOP by Giovanni Murguia B.Sc., Instituto Tecnol´ogicoy de Estudios Superiores de Monterrey, Mexico 2008 Supervisory Committee Dr. Hausi A. M¨uller,Supervisor (Department of Computer Science) Dr. Alex I. Thomo, Departamental Member (Department of Computer Science) iii Supervisory Committee Dr. Hausi A. M¨uller,Supervisor (Department of Computer Science) Dr. Alex I. Thomo, Departamental Member (Department of Computer Science) ABSTRACT As software systems have grown in size and complexity, the costs of maintaining such systems increases steadily. In the early 2000's, IBM launched the autonomic com- puting initiative to mitigate this problem by injecting feedback control mechanisms into software systems to enable them to observe their health and self-heal without human intervention and thereby cope with certain changes in their requirements and environments. Self-healing is one of several fundamental challenges addressed and includes software systems that are able to recover from failure conditions. There has been considerable research on software architectures with feedback loops that allow a multi-component system to adjust certain parameters automatically in response to changes in its environment.
    [Show full text]
  • Test-‐Driven Development Step Patterns for Designing Objects
    Test-Driven Development Step Patterns For Designing Objects Dependencies EDUARDO GUERRA, National Institute for Space Research, Brazil JOSEPH YODER, Refactory Inc., USA MAURÍCIO FINAVARO ANICHE, University of São Paulo, Brazil MARCO AURÉLIO GEROSA, University of São Paulo, Brazil Test-driven development (TDD) is a development technique often used to design classes in a software system by creating tests before their actual code. The dependency management and class APIs decisions, that emerge during the practice of TDD, does not "just happen": the way that the tests are created should be used in this process to make decisions and drive the design in the desired direction. This paper introduces four patterns that document the kinds of TDD cycles that can be performed to guide the design in the desired direction. These patterns are part of a pattern language that intends to present recurrent solutions that are used in a TDD process. Categories and Subject Descriptors: D.1.5 [Programming Techniques]: Object-oriented Programming; D.2.11 [Software Architectures]: Patterns General Terms: Test driven development Additional Key Words and Phrases: TDD, softWare design, patterns ACM Reference Format: Guerra, E., Yoder, J., Aniche, M. and Gerosa, M.. 2013. Test-Driven Development Step Patterns For Designing Objects Dependencies. Proceedings of the 20th Conference on Pattern Languages of Programs (PLoP). October 2013, 15 pages. 1. INTRODUCTION Test-driven development (TDD) is a technique in Which the tests are Written before the production code (Beck 2002). By using it, the development occurs in cycles, comprised of the creation of an automated test, an update on the developed softWare to make the test pass, and a code refactoring to improve the solution.
    [Show full text]
  • To Mock Or Not to Mock?
    Delft University of Technology To Mock or Not To Mock? An Empirical Study on Mocking Practices Spadini, Davide; Aniche, Maurício; Bruntink, Magiel; Bacchelli, Alberto DOI 10.1109/MSR.2017.61 Publication date 2017 Document Version Accepted author manuscript Published in Proceedings - 2017 IEEE/ACM 14th International Conference on Mining Software Repositories, MSR 2017 Citation (APA) Spadini, D., Aniche, M., Bruntink, M., & Bacchelli, A. (2017). To Mock or Not To Mock? An Empirical Study on Mocking Practices. In Proceedings - 2017 IEEE/ACM 14th International Conference on Mining Software Repositories, MSR 2017 (pp. 402-412). [7962389] IEEE . https://doi.org/10.1109/MSR.2017.61 Important note To cite this publication, please use the final published version (if applicable). Please check the document version above. Copyright Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons. Takedown policy Please contact us and provide details if you believe this document breaches copyrights. We will remove access to the work immediately and investigate your claim. This work is downloaded from Delft University of Technology. For technical reasons the number of authors shown on this cover page is limited to a maximum of 10. Delft University of Technology Software Engineering Research Group Technical Report Series To Mock or Not To Mock? An Empirical Study
    [Show full text]
  • Private API Access and Functional Mocking in Automated Unit Test Generation
    Private API Access and Functional Mocking in Automated Unit Test Generation Andrea Arcuri Gordon Fraser René Just Westerdals Oslo ACT University of Sheffield University of Massachusetts Oslo, Norway, Sheffield, UK Amherst, MA, USA and SnT, University of Luxembourg Abstract—Not all object oriented code is easily testable: 1 public interface AnInterface { Dependency objects might be difficult or even impossible to 2 boolean isOK(); instantiate, and object-oriented encapsulation makes testing po- 3 } tentially simple code difficult if it cannot easily be accessed. 4 5 public class PAFM { When this happens, then developers can resort to mock objects 6 that simulate the complex dependencies, or circumvent object- 7 public void example(AnInterface x) { oriented encapsulation and access private APIs directly through 8 if(System.getProperty("user.name").equals("root")) { the use of, for example, Java reflection. Can automated unit test 9 checkIfOK(x); 10 } generation benefit from these techniques as well? In this paper 11 } we investigate this question by extending the EvoSuite unit test 12 generation tool with the ability to directly access private APIs 13 private boolean checkIfOK(AnInterface x){ and to create mock objects using the popular Mockito framework. 14 if(x.isOK()){ 15 return true; However, care needs to be taken that this does not impact the 16 } else{ usefulness of the generated tests: For example, a test accessing a 17 return false; private field could later fail if that field is renamed, even if that 18 } renaming is part of a semantics-preserving refactoring. Such a 19 } } failure would not be revealing a true regression bug, but is a 20 false positive, which wastes the developer’s time for investigating and fixing the test.
    [Show full text]
  • Automated Unit Test Generation for Classes with Environment Dependencies
    Automated Unit Test Generation for Classes with Environment Dependencies Andrea Arcuri Gordon Fraser Juan Pablo Galeotti Certus Software V&V Center University of Sheffield Saarland University – Simula Research Laboratory Dep. of Computer Science Computer Science Lysaker, Norway Sheffield, UK Saarbrücken, Germany ABSTRACT 1 public class EnvExample { 2 Automated test generation for object-oriented software typically 3 public boolean checkContent() throws Exception{ consists of producing sequences of calls aiming at high code cov- 4 erage. In practice, the success of this process may be inhibited 5 Scanner console = new Scanner(System.in); when classes interact with their environment, such as the file sys- 6 String fileName = console.nextLine(); 7 console.close(); tem, network, user-interactions, etc. This leads to two major prob- 8 lems: First, code that depends on the environment can sometimes 9 File file = new File(fileName); not be fully covered simply by generating sequences of calls to a 10 if(!file.exists()) 11 return false; class under test, for example when execution of a branch depends 12 on the contents of a file. Second, even if code that is environment- 13 Scanner fromFile = new Scanner(new FileInputStream( dependent can be covered, the resulting tests may be unstable, i.e., file)); 14 String fileContent = fromFile.nextLine(); they would pass when first generated, but then may fail when exe- 15 fromFile.close(); cuted in a different environment. For example, tests on classes that 16 String date = DateFormat.getDateInstance(DateFormat. make use of the system time may have failing assertions if the tests SHORT).format(new Date()); 17 if(fileContent.equals(date)) are executed at a different time than when they were generated.
    [Show full text]
  • Assessing Mock Classes: an Empirical Study
    Assessing Mock Classes: An Empirical Study Gustavo Pereira, Andre Hora ASERG Group, Department of Computer Science (DCC) Federal University of Minas Gerais (UFMG) Belo Horizonte, Brazil fghapereira, [email protected] Abstract—During testing activities, developers frequently SinonJS1 and Jest,2 which is supported by Facebook; Java rely on dependencies (e.g., web services, etc) that make the developers can rely on Mockito3 while Python provides test harder to be implemented. In this scenario, they can use unittest.mock4 in its core library. The other solution to create mock objects to emulate the dependencies’ behavior, which contributes to make the test fast and isolated. In practice, mock classes is by hand, that is, manually creating emulated the emulated dependency can be dynamically created with the dependencies so they can be used in test cases. In this case, support of mocking frameworks or manually hand-coded in developers do not need to rely on any particular mocking mock classes. While the former is well-explored by the research framework since they can directly consume the mock class. literature, the latter has not yet been studied. Assessing mock For example, to facilitate web testing, the Spring web classes would provide the basis to better understand how those mocks are created and consumed by developers and to detect framework includes a number of classes dedicated to mock- 5 novel practices and challenges. In this paper, we provide the ing. Similarly, the Apache Camel integration framework first empirical study to assess mock classes. We analyze 12 provides mocking classes to support distributed and asyn- popular software projects, detect 604 mock classes, and assess chronous testing.6 That is, in those cases, instead of using their content, design, and usage.
    [Show full text]
  • David Keen Object Oriented Programming Mock Objects and Test Driven Design (TDD) the Text of This Essay Is My Own, Except Where
    David Keen Object Oriented Programming Mock Objects and test driven design (TDD) The text of this essay is my own, except where explicitly indicated. I give my permission for this essay to be submitted to the JISC Plagiarism Detection Service. Test every work of intellect or faith And everything that your own hands have wrought William Butler Yeats Mock Objects are a relatively new tool in the object oriented programmer's toolkit. Developed by Tim Mackinnon, Steve Freeman, and Philip Craig and first presented at the conference “eXtreme Programming and Flexible Processes in Software Engineering – XP2000”, Mock Objects are a powerful aid to Unit Testing and Test Driven Development. Many programmers are familiar with unit testing. Basically, this involves writing tests for some or all of the classes and methods in a program. There are a number of unit testing frameworks such as the xUnit family, first designed by Kent Beck for SmallTalk but now extended to more than twenty- five different frameworks for languages such as C++, Perl, Java and PHP. The goal of unit testing is to isolate each method or function and, through the use of an automated testing framework, write tests than can be repeatedly run to verify the correctness of the code. Having complete coverage of your code with unit tests gives you the confidence that any change you make to existing code does not introduce new errors in other parts of your program. Unit testing is an important part of the eXtreme Programming methodology as well as other Agile methodologies such as Scrum. But Test Driven Development is more than just unit testing.
    [Show full text]
  • Big Data - an Overview
    Faculty of Computer University Automatic Science and Politehnica Control and Engineering of Bucharest Computers Department Big Data - An Overview - Ciprian-Octavian Truică [email protected] Overview • What is Big Data? • Why Big Data? • Types of Big Data • Techniques • Distributed architecture • Cloud Computing • Storage and tools 03.10.2018 2 What is Big Data? • Big Data is high volume, high velocity and high variety of data that require new forms of processing to enable knowledge extraction, insight discovery, decision making, and process optimization 03.10.2018 3 What is Big Data? 03.10.2018 4 What is Big Data? • The 4 V’s of Big Data: 1. Volume – The main characteristic of Big Data is the volume – The volume of data impacts its analysis – Historical data is important especially for Business Intelligence – Data generated from different sources are stored together to create correlations and extract knowledge. 03.10.2018 5 What is Big Data? • The 4 V’s of Big Data: 2. Variety – Variety refers to the types of data available for analysis – Multiple types of data: numbers, dates, text, images, video, etc. – Multiple sources for data: companies databases, social media, blogs, etc. – Structured, unstructured and hybrid types of data. 03.10.2018 6 What is Big Data? • The 4 V’s of Big Data: 3. Veracity – Veracity refers to the trustworthiness of the data. – The quality of the data can affect the analysis process – The data must be representative, relevant, consistent, accurate and current to discover patterns – The data must be preprocessed to extract relevant knowledge 03.10.2018 7 What is Big Data? • The 4 V’s of Big Data: 4.
    [Show full text]