DOCSLIB.ORG

Pitfalls & Challenges Faced During a Microservices Architecture Implementation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Pitfalls & Challenges Faced During a Microservices Architecture Implementation Cognizant 20-20 Insights Cognizant Digital Systems & Technology Pitfalls & Challenges Faced During a Microservices Architecture Implementation Microservices are the de facto design approach for building digital applications. However, issues highlighted in this paper can and do lead to implementation challenges and even failures. Here are a few strategies to avoid and overcome them. Executive Summary Organizations across industries are at various stages suboptimal implementations of microservices of their journey toward adopting a microservices architectures that have emerged since our initial take architecture style.1 Some have been successful in on the topic.2 delivering real business benefits, while others are This white paper provides readers with guidance on still experimenting. fundamental design decisions required to properly While the benefits delivered by a microservices implement a microservices architecture to realize all the architecture such as agility, selective scalability and benefits available to organizations willing to take availability still hold true, we are dismayed by the various the plunge. February 2020 Some teams tend to think of the “micro” in microservices as a lever to design smaller-scoped systems, while others think of micro as the lever to deploy and operate manageable systems. Microservices architecture pitfalls A large number of the teams developing systems to be scoped? How we can maximize reuse for based on microservices architecture have a system component or service in its functional some form of experience in service-oriented form? Basically, identifying the right boundaries architecture (SOA) that was heavily influenced and granularity are two of the biggest challenges by the middleware vendor products such as for a solution designer, especially as the selection enterprise service buses (ESBs) or Web standards depends greatly on the domain and context of the such as Simple Object Access Protocol (SOAP) and solution space. Web Service. Application developers using microservices style While SOA experience helps in developing face similar challenges. Some teams tend to think service-oriented thinking, we have found that this of the “micro” in microservices as a lever to design background can also have a negative influence, smaller-scoped systems, while others think of micro resulting in pitfalls such as sub-optimal granularity as the lever to deploy and operate manageable of service, representational state transfer (REST)- systems. We see three major variations of this issue only mindset, excessive service calls (chatty in microservices scoping (see Figure 1, next page). services) and database as shared resource mindset. ❙ Entity scope: Data entity-oriented design Continuous technological improvements have tends to cause inflexibility at the individual caused some teams to fall into a technology-only microservices layer and change complexity at thinking trap, causing even more complexity when the overall system level. these systems experience high-volume production ❙ Process scope: Designing microservices at this traffic. These pitfalls manifest in multiple forms. level of granularity tends to result in fragile and (Read on to see what we have observed across volatile services. projects.) ❙ Utility scope: The notion of utilities treated as microservices causes the provisioning of The “micro” in microservices operational sophistication without reaping architecture adequate business benefits since such Application architects have struggled with the utilities are often non-differentiating to most granularity dilemma for a long time. What’s the enterprises. right level of granularity for a system component 2 / Pitfalls & Challenges Faced During a Microservices Architecture Implementation Cognizant 20-20 Insights Microservices granularity levels Policy Claim Customer ENTITY Email PROCESS Users Notification Issue policy UTILITY Address Process change claim Figure 1 While all granularity levels are expected to be microservice designers must pay close attention served in a system, the main benefits of such to the context-dependent interactions that architecture design can easily be missed; that is, the microservice needs to participate in. This balancing agility (speed of change) with resiliency requires the designers to think in terms of loosely (safety of change). Two issues are typically coupled, event-oriented boundaries and the observed: context mapping. ❙ It’s difficult to get business buy-in to the The database monolith program that’s delivering such services. Microservices adoption moved quickly from an ❙ Operational complexity increases without real emerging concept to the de facto design pattern benefits. for application architecture. However, as with any Finally, as IT organizations embrace a system over-hyped technology, the design patterns and paradigm across all non-trivial business domains, best practices were not very well established and event-oriented collaboration patterns have understood, which led to poor implementations. become a mainstay of such microsystem Among the major obstacles are large databases architecture design. These pitfalls tend to become a used as a persistent store for many -- or all -- of the big bottleneck that thwarts event-oriented thinking microservices. This database can lead to a monolith on the journey toward evolutionary system design. at the data persistence layer, resulting in several To avoid these pitfalls, IT organizations must ensure challenges such as: that no microservice is designed without an explicit ❙ Performance bottlenecks. One of the key alignment and traceability with business capability drivers for microservices architecture is the of the domain, as advocated by bounded context ability to scale horizontally and dynamically. strategy of domain-driven design.3 In addition, the 3 / Pitfalls & Challenges Faced During a Microservices Architecture Implementation Cognizant 20-20 Insights Quick Take Advancing Innovation & Time to Market in Consumer Lending One of our APAC clients in the consumer lending domain that wanted to enable innovation and improve speed-to-market transformed a single monolithic application into microservices with little or no focus on the design aspect of microservices. The result was 500-plus microservices with extreme complexity leading to performance bottlenecks due to chatty inter-service communication. We have recommended a domain-driven rationalization to address this situation. This not only helps address performance challenges, but also ensures evolution of the application in a completely autonomous manner. However, with a monolithic database, the scaling changes in other microservices, which defeats of microservices puts additional load on the the core purpose of microservices. database, creating a performance bottleneck. There are many reasons we have seen that lead to ❙ Coupling between microservices. this anti-pattern; two key ones are risk averseness Microservices architectures offer agility in that to move away from the monolithic database and they are loosely coupled and independently database designers who are not fully skilled in deployed. However, if multiple microservices are newer patterns like microservices, leading to tied to the same tables in the database, then any traditional database design. change in the schema will result in cascading If multiple microservices are tied to the same tables in the database, then any change in the schema will result in cascading changes in other microservices, which defeats the core purpose of microservices. 4 / Pitfalls & Challenges Faced During a Microservices Architecture Implementation Cognizant 20-20 Insights To avoid these pitfalls, IT organizations must ❙ Adopt CQRS pattern to use read replicas. ensure that the database design complements the Command query response segregation (CQRS) microservices by following best practices: is an architecture pattern but it can be applied to microservices database design to answer the ❙ Database per service in a no-share model. biggest question: Can data be shared between Each microservice needs to have full ownership microservices? of the data it requires. This does not mean a ❙ separate physical database but ownership of the Break distributed transactions with a saga 4 data it masters. pattern. The division of database objects into groups of logical schemas in bounded context of ❙ Polyglot persistence model. Making a the wider transaction boundaries require multi- relational database a default storage of all types phase commits. Avoid this with saga patterns of data leads to poor results, hence all types of that keep intermediate states. databases (e.g., NoSQL, Graph, in-memory, etc.) must be used. Quick Take Overcoming Centralized Database Shortcomings One of the new cloud-native features of a consumer lending solution implemented in pure microservices style was undermined by a single centralized relational database. This design led to the database becoming a performance bottleneck and hindrance to system scalability and resilience. We addressed this issue by refactoring the database into multiple domain-centric physical instances with microservices-based logical separations. This allowed domain-based isolation, which enabled resiliency, scalability and performance improvements. 5 / Pitfalls & Challenges Faced During a Microservices Architecture Implementation Cognizant 20-20 Insights Breaking the data monolith through bounded context and polyglot design MS 1 MS 2 MS 1 MS 2 MS 3 Full access Full access Read only
Load more

Recommended publications
  • Software Architecture: Past, Present, Future
    Software Architecture: Past, Present, Future Wilhelm Hasselbring 1 Introduction For large, complex software systems, the design of the overall system structure (the software architecture) is an essential challenge. The architecture of a software system defines that system in terms of components and connections among those components [55, 58]. It is not the design of that system which is more detailed. The architecture shows the correspondence between the requirements and the constructed system, thereby providing some rationale for the design decisions. This level of design has been addressed in a number of ways including informal diagrams and descriptive terms, module interconnection languages, and frameworks for systems that serve the needs of specific application domains. An architecture embodies decisions about quality properties. It represents the earliest opportunity for evaluating those decisions. Furthermore, reusability of components and services depends on how strongly coupled they are with other components in the system architecture. Performance, for instance, depends largely upon the complexity of the required coordination, in particular when the components are distributed via some network. The architecture is usually the first artifact to be examined when a programmer (particularly a maintenance programmer) unfamiliar with the system begins to work on it. Software architecture is often the first design artifact that represents decisions on how requirements of all types are to be achieved. As the manifestation of early design decisions, it represents design decisions that are hardest to change and hence most deserving of careful consideration. W. Hasselbring () Kiel University, Kiel, Germany e-mail: [email protected] © The Author(s) 2018 169 V.
    [Show full text]
  • An Experimental Study on Microservices Based Edge Computing Platforms Qian Qu, Ronghua Xu, Seyed Yahya Nikouei, Yu Chen Dept
    1 An Experimental Study on Microservices based Edge Computing Platforms Qian Qu, Ronghua Xu, Seyed Yahya Nikouei, Yu Chen Dept. of Electrical & Computer Engineering, Binghamton University, SUNY, Binghamton, NY 13902, USA fqqu2, rxu22, snikoue1, [email protected] Abstract—The rapid technological advances in the Internet of development and easy deployment among multiple service Things (IoT) allows the blueprint of Smart Cities to become providers. feasible by integrating heterogeneous cloud/fog/edge computing Because of many attractive features, such as good scalabil- paradigms to collaboratively provide variant smart services in our cities and communities. Thanks to attractive features like fine ity, fine granularity, loose coupling, continuous development, granularity and loose coupling, the microservices architecture and low maintenance cost, the microservices architecture has has been proposed to provide scalable and extensible services in emerged and gained a lot of interests both in industry and large scale distributed IoT systems. Recent studies have evaluated academic community [17], [21]. Compared to traditional SOAs and analyzed the performance interference between microser- in which the system is a monolithic unit, the microservices vices based on scenarios on the cloud computing environment. However, they are not holistic for IoT applications given the architecture divides an monolithic application into multiple restriction of the edge device like computation consumption and atomic microservices that run independently on distributed network capacity. This paper investigates multiple microservice computing platforms. Each microservice performs one specific deployment policies on edge computing platform. The microser- sub-task or service, which requires less computation resource vices are developed as docker containers, and comprehensive ex- and reduces the communication overhead.
    [Show full text]
  • Comparing Service- Based Architectures
    Comparing Service- based Architectures @neal4d nealford.com 1 agenda Micro Service-oriented Service-based 2 Service-oriented Architecture 3 origins: hubs System B System A System C 4 origins: hubs System B System A System C System D (ftp only) 5 origins: hubs System E (http only) System B System A System C System D (ftp only) 6 origins: hubs System E (http only) System B System A System C System D (ftp only) 7 origins: hubs System E (http only) System B Integration System A Hub System C System D (ftp only) 8 origins: hubs System E (http only) System B Integration System A Hub System C System D (ftp only) 9 origins: hubs System E (http only) System B Integration System A Hub System C System D (ftp only) 10 origins: hubs looks great, but what about single point of failure and performance bottleneck considerations? 11 orchestration hub intelligent hub service oriented architecture / enterprise service bus pattern 12 service-oriented architecture abstraction service taxonomy shared resources middleware interoperability 13 service-oriented architecture business services BS BS BS BS BS BS message bus process choreographer service orchestrator enterprise services ES ES ES ES ES ES application services AS infrastructure services IS 14 service-oriented architecture business services BS BS BS BS BS BS messageabstract bus enterprise-level coarse-grained process choreographer owned and defined by business users data represented as WSDL, BPEL, XML, etc. service orchestrator no implementation - only name, input, and output enterpriseAre we services
    [Show full text]
  • Case Study on Building Data- Centric Microservices
    Case Study on Building Data- Centric Microservices Part I - Getting Started May 26, 2020 | Version 1.0 Copyright © 2020, Oracle and/or its affiliates Public DISCLAIMER This document in any form, software or printed matter, contains proprietary information that is the exclusive property of Oracle. Your access to and use of this confidential material is subject to the terms and conditions of your Oracle software license and service agreement, which has been executed and with which you agree to comply. This document and information contained herein may not be disclosed, copied, reproduced or distributed to anyone outside Oracle without prior written consent of Oracle. This document is not part of your license agreement nor can it be incorporated into any contractual agreement with Oracle or its subsidiaries or affiliates. This document is for informational purposes only and is intended solely to assist you in planning for the implementation and upgrade of the product features described. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions. The development, release, and timing of any features or functionality described in this document remains at the sole discretion of Oracle. Due to the nature of the product architecture, it may not be possible to safely include all features described in this document without risking significant destabilization of the code. TABLE OF CONTENTS DISCLAIMER INTRODUCTION ARCHITECTURE OVERVIEW Before You Begin Our Canonical Application
    [Show full text]
  • Evaluating Service-Oriented and Microservice Architecture Patterns to Deploy Ehealth Applications in Cloud Computing Environment
    applied sciences Article Evaluating Service-Oriented and Microservice Architecture Patterns to Deploy eHealth Applications in Cloud Computing Environment Huriviades Calderón-Gómez 1,2 , Luis Mendoza-Pittí 1,2 , Miguel Vargas-Lombardo 2,* , José Manuel Gómez-Pulido 1,3 , Diego Rodríguez-Puyol 3,4,5, Gloria Sención 6 and María-Luz Polo-Luque 3,7 1 Department of Computer Science, University of Alcalá, 28805 Alcalá de Henares, Spain; [email protected] (H.C.-G.); [email protected] (L.M.-P.); [email protected] (J.M.G.-P.) 2 e-Health and Supercomputing Research Group (GISES), Technological University of Panama, 0819-07289 Panama City, Panama 3 Department of Medicine and Medical Specialties, Ramón y Cajal Institute for Health Research (IRYCIS), 28034 Madrid, Spain; [email protected] (D.R.-P.); [email protected] (M.-L.P.-L.) 4 Foundation for Biomedical Research, Hospital Universitario Príncipe de Asturias, 28805 Alcalá de Henares, Spain 5 Department of Medicine and Medical Specialties, University of Alcalá, 28805 Alcalá de Henares, Spain 6 School of Medicine Autonomous, University of Santo Domingo, Santo Domingo 10105, Dominican Republic; [email protected] 7 Department of Nursing and Physiotherapy, University of Alcalá, 28801 Alcalá de Henares, Spain * Correspondence: [email protected] Citation: Calderón-Gómez, H.; Mendoza-Pittí, L.; Vargas-Lombardo, Abstract: This article proposes a new framework for a Cloud-based eHealth platform concept focused M.; Gómez-Pulido, J.M.; on Cloud computing environments, since current and emerging approaches using digital clinical Rodríguez-Puyol, D.; Sención, G.; history increasingly demonstrate their potential in maintaining the quality of the benefits in medical Polo-Luque, M.-L.
    [Show full text]
  • From Component-Based Architectures to Microservices: a 25-Years-Long Journey in Designing and Realizing Service-Based Systems
    From Component-based Architectures to Microservices: A 25-years-long Journey in Designing and Realizing Service-based Systems Giuseppe De Giacomo[0000−0001−9680−7658], Maurizio Lenzerini[0000−0003−2875−6187], Francesco Leotta[0000−0001−9216−8502], and Massimo Mecella[0000−0002−9730−8882] Sapienza Universit`adi Roma Dipartimento di Ingegneria Informatica Automatica e Gestionale fdegiacomo,lenzerini,leotta,[email protected] Abstract. Distributed information systems and applications are gen- erally described in terms of components and interfaces among them. How these component-based architectures have been designed and im- plemented evolved over the years, giving rise to the so-called paradigm of Service-Oriented Computing (SOC). In this chapter, we will follow a 25-years-long journey on how design methodologies and supporting technologies influenced one each other, and we discuss how already back in the late 90s the ancestors of the SOC paradigm were there, already paving the way for the technological evolution recently leading to mi- croservice architectures and serverless computing. Keywords: components · SOC · middleware technologies · microser- vices · design methodologies 1 Introduction Divide et impera1 describes an approach, relevant to many fields, where, to solve a problem, it is required or advantageous to break or divide what opposes the solution. As an example, in computer science and engineering, it is applied at the level of standalone programs, by organizing codes in functions, classes and libraries, but it is also at the basis of how complex business processes, spanning several departments/offices of the same organization and/or different organizations, are implemented by making different parties collaborating on a computer network [1].
    [Show full text]
  • Gremlin: Systematic Resilience Testing of Microservices
    Gremlin: Systematic Resilience Testing of Microservices Victor Heorhiadi Shriram Rajagopalan Hani Jamjoom Michael K. Reiter Vyas Sekar UNC Chapel Hill IBM T. J. Watson Research IBM T. J. Watson Research UNC Chapel Hill Carnegie Mellon University [email protected] [email protected] [email protected] [email protected] [email protected] Abstract—Modern Internet applications are being disaggre- Company Downtime Postmortem findings gated into a microservice-based architecture, with services Parse.ly, 13 hours Cascading failure due to message bus being updated and deployed hundreds of times a day. The 2015 [25] overload accelerated software life cycle and heterogeneity of language CircleCI, 17 hours Cascading failure due to database over- runtimes in a single application necessitates a new approach 2015 [19] load BBC, 48 hours Cascading failure due to database over- for testing the resiliency of these applications in production in- 2014 [18] load frastructures. We present Gremlin, a framework for systemat- Spotify, Several Cascading failure due to degradation of a ically testing the failure-handling capabilities of microservices. 2013 [26] hours core internal service Gremlin is based on the observation that microservices are Twilio, 10 hours Database failure caused billing service to loosely coupled and thus rely on standard message-exchange 2013 [28] repeatedly bill customers patterns over the network. Gremlin allows the operator to TABLE 1: A subset of recent outages experienced by popular, easily design tests and executes them by manipulating inter- highly available Internet services. Postmortem reports revealed service messages at the network layer. We show how to use missing or faulty failure-handling logic.
    [Show full text]
  • Testing Microservice Applications
    Dmitrii Savchenko TESTING MICROSERVICE APPLICATIONS ACTA UNIVERSITATIS LAPPEENRANTAENSIS 868 Dmitrii Savchenko TESTING MICROSERVICE APPLICATIONS Thesis for the degree of Doctor of Science (Technology) to be presented with due permission for public examination and criticism in the Auditorium of the Student Union House at Lappeenranta-Lahti University of Technology LUT, Lappeenranta, Finland on the 18th of October, 2019, at noon. The thesis was written under a joint doctorate agreement between Lappeenranta-Lahti University of Technology LUT, Finland and South Ural State University, Russia and jointly supervised by supervisors from both universities. Acta Universitatis Lappeenrantaensis 868 Supervisors Adjunct Professor Ossi Taipale LUT School of Engineering Science Lappeenranta-Lahti University of Technology LUT Finland Associate Professor Jussi Kasurinen LUT School of Engineering Science Lappeenranta-Lahti University of Technology LUT Finland Associate Professor Gleb Radchenko School of Electrical Engineering and Computer Science Department of System Programming Federal State Autonomous Educational Institution of High Education South Ural State University (National Research University) Russian Federation Reviewers Professor Timo Mantere Dept. of Electrical Engineering and Automation University of Vaasa Finland Professor Markku Tukiainen School of Computing University of Eastern Finland Joensuu Finland Opponent Professor Ita Richardson Lero - The Irish Software Research Centre University of Limerick Ireland ISBN 978-952-335-414-2 ISBN 978-952-335-415-9 (PDF) ISSN 1456-4491 ISSN-L 1456-4491 Lappeenranta-Lahti University of Technology LUT LUT University Press 2019 Abstract Dmitrii Savchenko Testing microservice applications Lappeenranta, 2019 59 p. Acta Universitatis Lappeenrantaensis 868 Diss. Lappeenranta-Lahti University of Technology LUT ISBN 978-952-335-414-2, ISBN 978-952-335-415-9 (PDF), ISSN-L 1456-4491, ISSN 1456- 4491 Software maintenance costs are growing from year to year because of the growing soft- ware complexity.
    [Show full text]
  • AN INSIGHT INTO MICROSERVICES TESTING STRATEGIES Arvind Sundar, Technical Test Lead
    WHITE PAPER AN INSIGHT INTO MICROSERVICES TESTING STRATEGIES Arvind Sundar, Technical Test Lead Abstract The ever-changing business needs of the industry necessitate that technologies adopt and align themselves to meet demands and, in the process of doing so, give rise to newer techniques and fundamental methods of architecture in software design. In the context of software design, the evolution of “microservices” is the result of such an activity and its impact percolates down to the teams working on building and testing software in the newer schemes of architecture. This white paper illustrates the challenges that the testing world has to deal with and the effective strategies that can be envisaged to overcome them while testing for applications designed with a microservices architecture. The paper can serve as a guide to anyone who wants an insight into microservices and would like to know more about testing methodologies that can be developed and successfully applied while working within such a landscape. Introduction Microservices attempt to streamline the key; as is a good knowledge of how to go software architecture of an application about testing at each stage of the test life by breaking it down into smaller units cycle. More often than not, the traditional surrounding the business needs of methods of testing have proven to be the application. The benefits that are ineffective in an agile world where changes expected out of doing so include creating are dynamic. The inclusion of independent systems that are more resilient, easily micro-units that have to be thoroughly scalable, flexible, and can be quickly and tested before their integration into the independently developed by individual larger application only increases the sets of smaller teams.
    [Show full text]
  • AWS Prescriptive Guidance Enabling Data Persistence in Microservices AWS Prescriptive Guidance Enabling Data Persistence in Microservices
    AWS Prescriptive Guidance Enabling data persistence in microservices AWS Prescriptive Guidance Enabling data persistence in microservices AWS Prescriptive Guidance: Enabling data persistence in microservices Copyright © Amazon Web Services, Inc. and/or its affiliates. All rights reserved. Amazon's trademarks and trade dress may not be used in connection with any product or service that is not Amazon's, in any manner that is likely to cause confusion among customers, or in any manner that disparages or discredits Amazon. All other trademarks not owned by Amazon are the property of their respective owners, who may or may not be affiliated with, connected to, or sponsored by Amazon. AWS Prescriptive Guidance Enabling data persistence in microservices Table of Contents Introduction ...................................................................................................................................... 1 Targeted business outcomes ........................................................................................................ 2 Patterns for enabling data persistence .................................................................................................. 3 Database-per-service pattern ....................................................................................................... 3 API composition pattern ............................................................................................................. 5 CQRS pattern ...........................................................................................................................
    [Show full text]
  • Finding Flexibility with Microservices, Containers, and Runtimes Featuring Research from Forrester How to Capture the Benefits of Microservice Design 2
    Finding Flexibility with Microservices, Containers, and Runtimes FEATURING RESEARCH FROM FORRESTER How To Capture The Benefits Of Microservice Design 2 Finding Flexibility with Microservices, Containers, and Runtimes FINDING FLEXIBILITY WITH MICROSERVICES, CONTAINERS, AND RUNTIMES An introduction to the Forrester analyst report: How to Capture the Benefits of Microservice Design There has always been a relationship between an application and the platform and services which run it. For a long time, that relationship was very tight and encompassed a lot of areas related to the IN THIS application design, from the language the application could be written in to administrative behaviors DOCUMENT like monitoring and logging, even things like transaction management, frontend UI development, or integration methods. 1 Finding Flexibility with Microservices, In a sense, the application platform was just another design consideration for the application. A few Containers, and years ago, as significant changes in platform technology like cloud, containers, and virtual machines Runtimes started rolling out, the primary emphasis for CTOs and application architects was on how to move to those platforms. The platform choice was a major part of the application. The focus was — one way or 5 How To Capture The Benefits Of another — getting into “the cloud.” Microservice Design There’s been a shift in customers’ priorities over the last few years. A 2016 survey of IT professionals by Red Hat found that fewer than 25% of respondents were actually focusing on moving applications 22 About redhat. to the cloud — the majority were focused on writing new applications or maintaining existing ones. The focus is moving from platform to the application itself.
    [Show full text]
  • Microsurfaces: the Role of Apis in a Microservice Architecture
    Microsurfaces: The Role of APIs in a Microservice Architecture 1 1 Microservices Adoption Continues to Grow in All Industries According to a recent survey, 86 percent of respondents expect microservice architecture to be their default approach to building software systems within five years. There are many reasons for moving to a microservice architecture, from increasing delivery speed to improving evolvability and scalability. However, there are also potential pitfalls as complexity shifts from place to place in the system and the associated organizational landscape. As a result, organizations moving to a microservice architecture need tools and techniques to help them deal with these new challenges. When it comes to microservice technologies, people have called containers the “gateway drug to microservices,” and containers can certainly ease deployment and operability. However, API-based communication may be even more vital to delivering value in all aspects of a microservice architecture. This ebook explores the varied roles that APIs play in the microservices landscape. 2 APIs vs. Microservices Before analyzing the value of APIs in a microservice architecture, it helps to clear up It is important to remember any confusion between the definitions of APIs and microservices. When someone says they are “building an API,” they are likely developing a microservice with an API that the API is just the interface, front door. Conversely, there are some who refer to API facades for legacy services as and even more important to microservices. Both examples blur the lines between the terms. remember that the service What is an API? What is a microservice? consumer views the API as a • An application interface exposedon a • An independently deployable contract, and they don’t care network application component what’s behind it as long as they • Can use many styles (e.g., REST), • Often self-contained (e.g., interface, get what they need.
    [Show full text]