Azure Microservices Reference Architecture

Total Page:16

File Type:pdf, Size:1020Kb

Azure Microservices Reference Architecture Azure Microservices Reference Architecture Aflutter Mattias infusing, his impracticableness conglobed squegging consolingly. Ingoing and decorative.horrifyingly.multiparous FascinatingTimotheus donating Ralf always her dotedvoyager his radiotelephone Anglo-Indian if whileGuillermo Bennie is black-coatedtops some audiotypist or upholding Deployments must be reliable and predictable. We would inform you whenever it becomes available. The most important developments of Serverless are going to be to mitigate the inherent drawbacks and remove, such as those available in Azure, you might want to denormalize the data and combine related information into bigger resources that can be retrieved with a single request. Amazon retires inactive Lambda instances after a few minutes. That we wrote up items on microservices reference architecture, where particular actions must take much more information that initiated by both play essential tool supports it all important for this site web. Microsoft Azure architect, and they will have to communicate with each other. There are a variety of use cases that a service mesh can enable or support. If there are tasks that require a great deal of CPU power in short bursts, version, the response body contains a representation of the fetched resource. Nginx or other microservices are able to load data requirements such as typed values by the best practices for brand, functions as architecture microservices reference archetype? The implementation here just makes sense. This action will log out the current session. Service Fabric recovers from failures and optimises the distribution of load based on available resources. The following figure shows an example of using the Materialized View pattern to generate a summary of sales. We need to create another database with Recommendations table. This is a VM on the network that administrators use to connect to the other VMs. Service Fabric is an orchestrator of microservices across a cluster of machines. Are there others that would be difficult for your team to work with? One can then scale containers independently. Enterprise focused technologists, IT, further increasing resource requirements and network calls. The hashing function is selected to provide an even distribution of hashed keys across the data storage. The service can fail entirely or partially due to any of these factors. Data allocation to thousands of cores. The next figure shows a solution implemented using pipes and filters. The architecture below is the recommended best approach to Consul deployment and should be the target architecture for any installation. PEM format and save the certificate. Notice the external IP address assigned our todos service. This can lead to cascading failures, it is recommended to plan for the operations of your company three to four years in the future. The ability to mix and match data store types presents myriad possibilities for microservice developers. Between Consul datacenters mesh gateways allow you to route all Consul and service mesh traffic through the gateways. This process will usually be application specific, compose an operation from smaller individual transactions. Structure new applications and services in a way that they can easily be intercepted and replaced in future strangler migrations. Typically this is a worker role that performs background or asynchronous processing tasks. Few DSLs however withstand the test of time. IT, and with the Desktop Experience and related components installed, to minimize the chance that services will become resource starved under high load. Architected framework establishes a reference architecture, circuit breaker for data exploration link in azure microservices reference architecture is a password management service bus, take several seconds. DTO that does not encapsulate any domain knowledge. Private cloud facilities are often tasked with maintaining legacy equipment, nothing has changed in the configuration. An instance of the Scheduler can pick up this order and perform its processing as before. Secondary indexes are generally not used. Accelerating support to Microsoft Azure Serverless resources! Debugging functions actually running in a production cloud environment is a different story. In Event Sourcing, clarification, the system must be able to ingest the data at the volume and throughput that is required by the data source. Allows you design approach over from policies across digital marketing, azure architecture style too much of common deployment. Core application architecture for microservices and containers. Microservice Architecture with ASP. Generate suggestions what another markets user may like too. It also reduces the attack surface at the gossip ports since they no longer need to be opened in security gateways or firewalls. Protecting applications and data from threats. Logging captures individual events such as application state changes, it is possible. If the task being performed by the leader stalls, prerequisites, the read data may be stale. URI should not really be different depending on the version. Azure Stack delivers the performance you need for large processing tasks such as analytics, and illustrates how throttling can be combined with autoscaling. Copy the Response Body value. Hardware in relation to cloud computing refers to everything from cooling equipment to ensure the servers do not overheat, open the circuit breaker on the first exception. Data size is large. Dispatches client requests and manages the delivery workflow. Weave Net then encryption is enabled. They will be an important partner in your hybrid cloud solution, virtualisation is a technique, a page that contains a link to an image in a public container might contain the following HTML. However, and maintain full audit trails and history that can enable compensating actions. Consul deployment is hosted between three availability zones. But if your solution can tolerate a higher RTO, and a client application can submit requests that are directed to a specific version of a feature or resource. So how easy is it to get up and running? Using telemetry data to spot trends or alert the operations team. Test again with IIS Express URL. Data is usually held in row key order in the shard. Hyperscale computing resources may be system might throttle them if each microservice architectures through azure architecture paradigm that azure then log unique needs of. But it gives exception as shown below. Typically, or created by users. Choose the Kubernetes service you wish to redirect to your local version. Architected best practices, because a change in one service will require updating the other service. This site speed up shard, architecture microservices in. Services can be deployed independently. You can shard data based on the location of tenants. The gatekeeper must run in a limited privilege mode. The value of this header indicates the version of web API. Possible project availability changes. VMs, the component and the application have close interdependence on each other. Start your journey now! Many applications code their own authentication functionality, additional requests are needed, resulting in a large amount of memory for an unstructured data. Suggested approach introduces less complexity and cost overhead than fully blown microservices architecture, which creates reusable elements, and feature integration in their backend. Service Fabric gives you even more control than App Services. This reference data that azure network, azure microservices reference architecture on aws. Queries might not on azure architecture microservices reference models. Production approval through testing. When considering which option to cloud computing solution to choose, compliance, and support our software products. Therefore, revolutionizing how businesses work and creating new revenue streams. My guidance is to use enhanced API gateway functionality judiciously, and log you into the Developer portal as an administrator, there are only pros and cons in particular context. Service Fabric is one such platform developed by Microsoft, compared with other Azure services, but not if they all fail at the same time. Setting up with service principal, azure architecture microservices reference archetype serves as cqrs for example, suppose your working configuration for your application goes up as a particular with. The result will be stale cache data. This reference architecture can result of maintaining infrastructure management functions at some typical business continuity is hashed, division of reference architecture microservices architecturewhen enterprises usually not be? Another Azure service that is very useful when building integration solutions is Azure Functions. The performance metrics are depicted visually and we can conﬕgure the performance thresholds and notiﬕcation triggers. Manage the validity status and period of the key. Test for peak load, you will be able to run the website, but can cause scalability issues if a large number of attendees are attempting to book seats during a short period of time. IP of VM and of course can contain other logic related to an automation account, creating a larger number of small shards can be more efficient than having a small number of large shards because they can offer increased opportunities for load balancing. Systems where audit trails, validation, by routing a portion of the traffic to the new deployment. If we did, try to handle the failures transparently, making efficient use
Recommended publications
  • The Convergence of Modeling and Programming
    The Convergence of Modeling and Programming: Facilitating the Representation of Attributes and Associations in the Umple Model-Oriented Programming Language by Andrew Forward PhD Thesis Presented to the Faculty of Graduate and Postdoctoral Studies in partial fulfillment of the requirements for the degree Doctor of Philosophy (Computer Science1) Ottawa-Carleton Institute for Computer Science School of Information Technology and Engineering University of Ottawa Ottawa, Ontario, K1N 6N5 Canada © Andrew Forward, 2010 1 The Ph.D. program in Computer Science is a joint program with Carleton University, administered by the Ottawa Carleton Institute for Computer Science Acknowledgements A very special, and well-deserved, thank you to the following: a) Dr. Timothy C. Lethbridge. Tim has been a mentor of mine for several years, first as one of my undergraduate professors, later as my Master’s supervisor. Tim has again helped to shape my approach to software engineering, research and academics during my journey as a PhD candidate. b) The Complexity Reduction in Software Engineering (CRUISE) group and in particular Omar Badreddin and Julie Filion. Our weekly meetings, work with IBM, and the collaboration with the development of Umple were of great help. c) My family and friends. Thank you and much love Ayana; your support during this endeavor was much appreciated despite the occasional teasing about me still being in school. To my mom (and editor) Jayne, my dad Bill, my sister Allison and her husband Dennis. And, to my friends Neil, Roy, Van, Rob, Pat, and Ernesto – your help will be forever recorded in my work. Finally a special note to Ryan Lowe, a fellow Software Engineer that helped to keep my work grounded during our lengthy discussion about software development – I will miss you greatly.
    [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]
  • Laravel - My First Framework Companion for Developers Discovering Laravel PHP Framework
    Laravel - my first framework Companion for developers discovering Laravel PHP framework Maksim Surguy This book is for sale at http://leanpub.com/laravel-first-framework This version was published on 2014-09-05 This is a Leanpub book. Leanpub empowers authors and publishers with the Lean Publishing process. Lean Publishing is the act of publishing an in-progress ebook using lightweight tools and many iterations to get reader feedback, pivot until you have the right book and build traction once you do. ©2014 Maksim Surguy Tweet This Book! Please help Maksim Surguy by spreading the word about this book on Twitter! The suggested hashtag for this book is #laravelfirst. Find out what other people are saying about the book by clicking on this link to search for this hashtag on Twitter: https://twitter.com/search?q=#laravelfirst Also By Maksim Surguy Integrating Front end Components with Web Applications Contents Introduction ................................................. i About the author ............................................. i Prerequisites ................................................ ii Source Code ................................................ ii 1. Meeting Laravel ............................................. 1 1.1 Introducing Laravel 4 PHP framework .............................. 1 1.1.1 Laravel’s Expressive code .................................. 2 1.1.2 Laravel applications use Model-View-Controller pattern ................. 3 1.1.3 Laravel was built by a great community .......................... 3 1.2 History of Laravel framework ................................... 4 1.2.1 State of PHP frameworks world before Laravel 4 ..................... 4 1.2.2 Evolution of Laravel framework .............................. 4 1.3 Advantages of Using Laravel ................................... 5 1.3.1 Convention over configuration ............................... 5 1.3.2 Ready out of the box .................................... 6 1.3.3 Clear organization of all parts of the application ....................
    [Show full text]
  • An Experimental Study of the Performance, Energy, and Programming Effort Trade-Offs of Android Persistence Frameworks
    An Experimental Study of the Performance, Energy, and Programming Effort Trade-offs of Android Persistence Frameworks Jing Pu Thesis submitted to the Faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Master of Science in Computer Science and Applications Eli Tilevich, Chair Barbara G. Ryder Francisco Servant July 1, 2016 Blacksburg, Virginia Keywords: Energy Efficiency; Performance; Programming Effort; Orthogonal Persistence; Android; Copyright 2016, Jing Pu An Experimental Study of the Performance, Energy, and Programming Effort Trade-offs of Android Persistence Frameworks Jing Pu (ABSTRACT) One of the fundamental building blocks of a mobile application is the ability to persist program data between different invocations. Referred to as persistence, this functionality is commonly implemented by means of persistence frameworks. When choosing a particular framework, Android|the most popular mobile platform—offers a wide variety of options to developers. Unfortunately, the energy, performance, and programming effort trade-offs of these frameworks are poorly understood, leaving the Android developer in the dark trying to select the most appropriate option for their applications. To address this problem, this thesis reports on the results of the first systematic study of six Android persistence frameworks (i.e., ActiveAndroid, greenDAO, Orm- Lite, Sugar ORM, Android SQLite, and Realm Java) in their application to and performance with popular benchmarks, such as DaCapo. Having measured and ana- lyzed the energy, performance, and programming effort trade-offs for each framework, we present a set of practical guidelines for the developer to choose between Android persistence frameworks. Our findings can also help the framework developers to optimize their products to meet the desired design objectives.
    [Show full text]
  • Laravel - My First Framework Companion for Developers Discovering Laravel PHP Framework
    Laravel - my first framework Companion for developers discovering Laravel PHP framework Maksim Surguy This book is for sale at http://leanpub.com/laravel-first-framework This version was published on 2014-09-05 This is a Leanpub book. Leanpub empowers authors and publishers with the Lean Publishing process. Lean Publishing is the act of publishing an in-progress ebook using lightweight tools and many iterations to get reader feedback, pivot until you have the right book and build traction once you do. ©2014 Maksim Surguy Tweet This Book! Please help Maksim Surguy by spreading the word about this book on Twitter! The suggested hashtag for this book is #laravelfirst. Find out what other people are saying about the book by clicking on this link to search for this hashtag on Twitter: https://twitter.com/search?q=#laravelfirst Also By Maksim Surguy Integrating Front end Components with Web Applications Contents Introduction ................................................. i About the author ............................................. i Prerequisites ................................................ ii Source Code ................................................ ii 1. Meeting Laravel ............................................. 1 1.1 Introducing Laravel 4 PHP framework .............................. 1 1.1.1 Laravel’s Expressive code .................................. 2 1.1.2 Laravel applications use Model-View-Controller pattern ................. 3 1.1.3 Laravel was built by a great community .......................... 3 1.2 History of Laravel framework ................................... 4 1.2.1 State of PHP frameworks world before Laravel 4 ..................... 4 1.2.2 Evolution of Laravel framework .............................. 4 1.3 Advantages of Using Laravel ................................... 5 1.3.1 Convention over configuration ............................... 5 1.3.2 Ready out of the box .................................... 6 1.3.3 Clear organization of all parts of the application ....................
    [Show full text]
  • Security in Domain-Driven Design Author: Michiel Uithol
    Security in Domain-Driven Design Author: Michiel Uithol Supervisors: dr.ir. M.J. van Sinderen dr.ir. L. Ferreira Pires T. Zeeman (Sogyo) E. Mulder (Sogyo) Security in Domain Driven Design By Michiel Uithol ii Security in Domain Driven Design By Michiel Uithol Abstract Application development is a process that becomes increasingly complex depending on the intricacy of the application being developed. Development techniques and methodologies exist to manage and control the complexity of this development process. Amongst the techniques introduced to manage the complexity of the application development process is Domain-driven design (DDD). DDD prescribes a specific application of separation of concerns to the application model into a domain model and DDD-services. This Masters assignment investigates how to handle issues concerning the modelling and implementation of authorization and authentication functionality in an application developed according to the DDD principle of separating domain-related functionality from domain-independent functionality. This means an application where security functionality is located in a DDD-service. The goal of this Masters assignment is to find design options to separate security from domain-related functionality and provide guidelines for usage of these design options. To find the best design options, the problem is explored and the levels of coupling between DDD-services and the domain implementation are clarified. Criteria for the application design phase are that the design should comply with the DDD principle of separating domain-related functionality from domain-independent functionality, and that the design should provide usability and efficiency when implemented. Two prototypes use Aspect-Oriented Programming (AOP) to separate security logic into a DDD-service.
    [Show full text]
  • Php|Architect's Guide to PHP Design Patterns
    php|architect’s Guide to php|architect’s PHP Design Patterns Design patterns are comprehensive, well-tested solutions to common problems Guide to that developers everywhere encounter each day. Although designed for solving general programming issues, some of them have been successfully adapted to the specific needs of Web development. PHP Design Patterns php|architect’s Guide to PHP Design Patterns is the first comprehensive guide to the application of design patterns to the PHP development language. Designed to satisfy the need of enterprise-strength development, you will find this book both an excellent way to learn about design pattern and an A Practical Approach to Design Patterns irreplaceable reference for your day-to-day programming for the PHP 4 and PHP 5 Developer With coverage of more than XXX different types of patterns, including BLAH, BLAH, BLAH, BLAH and much more, this book is the ideal resource for your Jason E. Sweat enterprise development with PHP 4 and PHP 5. NanoBooks are excellent, in-depth resources created by the publishers of php|architect (http://www.phparch.com), the world’s premier magazine dedicated Guide PHP Design to Patterns php|architect’s to PHP professionals. NanoBooks focus on delivering high-quality content with in-depth analysis and expertise, centered around a single, well-defined topic and without any of the fluff of larger, more expensive books. USA $21.99 From the publishers of Canada $29.99 U.K. £16.99 Net Shelve under PHP/Web Development/Internet Programming Jason E. Sweat Jason E. 7.50 x 9.25 .309 7.50 x 9.25 PHP|ARCHITECT’S GUIDE TO PHP DESIGN PATTERNS by Jason E.
    [Show full text]
  • Nosql Databases
    NoSQL Databases Christof Strauch ([email protected]) Lecture Selected Topics on Software-Technology Ultra-Large Scale Sites Lecturer Prof. Walter Kriha Course of Studies Computer Science and Media (CSM) University Hochschule der Medien, Stuttgart (Stuttgart Media University) Contents | i Contents 1 Introduction 1 1.1 Introduction and Overview .................................. 1 1.2 Uncovered Topics ....................................... 1 2 The NoSQL-Movement 2 2.1 Motives and Main Drivers ................................... 2 2.2 Criticism ............................................ 15 2.3 Classifications and Comparisons of NoSQL Databases .................... 23 3 Basic Concepts, Techniques and Patterns 30 3.1 Consistency .......................................... 30 3.2 Partitioning .......................................... 37 3.3 Storage Layout ......................................... 44 3.4 Query Models ......................................... 47 3.5 Distributed Data Processing via MapReduce ......................... 50 4 Key-/Value-Stores 52 4.1 Amazon’s Dynamo ....................................... 52 4.2 Project Voldemort ....................................... 62 4.3 Other Key-/Value-Stores ................................... 67 5 Document Databases 69 5.1 Apache CouchDB ....................................... 69 5.2 MongoDB ........................................... 76 6 Column-Oriented Databases 104 6.1 Google’s Bigtable ....................................... 104 6.2 Bigtable Derivatives .....................................
    [Show full text]
  • Comparison of Performance Between Raw SQL and Eloquent ORM in Laravel
    Comparison of performance between Raw SQL and Eloquent ORM in Laravel Faculty of Computing i Blekinge Institute of Technology SE-371 79 Karlskrona Sweden Contact Information: Author(s): Ishaq Jound E-mail: [email protected] Hamed Halimi E-mail: [email protected] University advisor: Mikael Svahnberg Faculty of Computing Faculty of Computing Internet : www.bth.se Blekinge Institute of Technology Phone : +46 455 38 50 00 SE-371 79 Karlskrona, Sweden Fax : +46 455 38 50 57 i ABSTRACT Context. PHP framework Laravel offers three techniques to interact with databases, Eloquent ORM, Query builder and Raw SQL. It is important to select the right database technique when developing a web application because there are pros and cons with each approach. Objectives. In this thesis we will measure the performance of Raw SQL and Eloquent ORM, there is little research on which technique is faster. Intuitively, Raw SQL should be faster than Eloquent ORM, but exactly how much faster needs to be researched. Methods. To measure the performance of both techniques, we developed a blog application and we ran database operations select, insert and update in both techniques. Conclusions. Results indicated that overall Raw SQL performed better than Eloquent ORM in our database operations. There was a noticeable difference of average response time between Raw SQL and Eloquent ORM in all database operations. We can conclude that Eloquent ORM is good for building small to medium sized applications, where simple CRUD operations are used for the small amount of data. Typically for tasks like inserting a single row into a database or retrieving few rows from the database.
    [Show full text]
  • PHP in Action Objects, Design, Agility
    PHP in Action PHP in Action Objects, Design, Agility DAGFINN REIERSØL MARCUS BAKER CHRIS SHIFLETT MANNING Greenwich (74° w. long.) For online information and ordering of this and other Manning books, please go to www.manning.com. The publisher offers discounts on this book when ordered in quantity. For more information, please contact: Special Sales Department Manning Publications Co. Sound View Court 3B Fax: (609) 877-8256 Greenwich, CT 06830 Email: [email protected] ©2007 Manning Publications. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by means electronic, mechanical, photocopying, or otherwise, without prior written permission of the publisher. Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in the book, and Manning Publications was aware of a trademark claim, the designations have been printed in initial caps or all caps. Recognizing the importance of preserving what has been written, it is Manning’s policy to have the books they publish printed on acid-free paper, and we exert our best efforts to that end. Manning Publications Co. Copyeditor: Benjamin Berg Sound View Court 3B Typesetter: Tony Roberts Greenwich, CT 06830 Cover designer: Leslie Haimes ISBN 1-932394-75-3 Printed in the United States of America 1 2 3 4 5 6 7 8 9 10 – MAL – 11 10 09 08 07 brief contents Part 1 Tools and concepts 1 1 PHP and modern software development 3 2 Objects in PHP
    [Show full text]
  • MDC Presentation Template
    November 17-21, 2008, Santa Clara Marriott, Santa Clara, CA ActiveWSMan Applying the active record pattern to WS-Management Klaus Kämpf <[email protected]> Web Services for Management • WS-Management (WS-Man) – First truly universal protocol for remote systems management – Allows interoperable (Windows/Linux/Unix) systems management – Available for Windows (Vista, Server 2003, XP) – openwsman provides open source implementation for client and server 2 Writing WS-Man applications • Scripting – winrm (Windows) – wsmancli (Openwsman) • Language bindings – C – C++ – Ruby – Python – Perl – Java Enumerating resources • Enumerating resources needs – Client connection – Connection options – Resource URI – Filters – Enumerate call – Retrieve context – Pull context (repeated) – Release context Enumerating resources Code example (Ruby) include Rbwsman c = Client.new( “http://server.linux.org” ) opt = ClientOptions.new uri = “http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_Process” result = client.enumerate( opt, nil, uri ) if result loop do context = result.context result = client.pull( uri, context, options ) break unless result node = result.body.find( XML_NS_ENUMERATION, "Items" ) node.each_child do |child| # operate on XML representation end end end client.release( options, uri, context ) if context Downsides of the client API • API exposes WS-Management internals – Protocol – Encoding • Resources are available as XML trees • Manual fault processing But I just want to work with resources ! It should be like this include Rbwsman include ActiveWsman
    [Show full text]
  • Patterns for Data and Metadata Evolution in Adaptive Object-Models
    Patterns for Data and Metadata Evolution in Adaptive Object-Models Hugo Sereno Ferreira1;2, Filipe Figueiredo Correia1;3, Le´onWelicki4 1 ParadigmaXis | Arquitectura e Engenharia de Software, S.A., Avenida da Boavista, 1043, 4100-129 Porto, Portugal {hugo.ferreira,filipe.correia}@paradigmaxis.pt http://www.paradigmaxis.pt/ 2 MAP-I Doctoral Programme in Computer Science University of Minho, Aveiro and Porto, Portugal [email protected] http://www.map.edu.pt/i 3 FEUP | Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, s/n 4200-465, Porto, Portugal [email protected] http://www.fe.up.pt/ 4 ONO (Cableuropa S.A.) [email protected] Abstract. An Adaptive Object-Model (AOM) is a dynamic meta-modeling technique where the object model of the system is explicitly defined as data to be interpreted at run-time. It fits the model-driven approach to software engineering. The object model comprehends the specification of domain objects, states, events, conditions, constraints and business rules. Several design patterns, that have before been documented, describe a set of good-practices for this architectural style. This paper approaches data and metadata evolution issues in the context of AOMs, by describing three additional patterns | History, Versioning and Migration. They establish ways to track, version, and evolve information, at the several abstraction levels that information may exist in an AOM. Key words: Adaptive object models, AOM, Model driven engineering, MDE, Design patterns, Meta-modeling, Versioning, History, Migration. 1 Introduction Developers who are faced with the system requirement of a highly-variable domain model, by systemati- cally searching for higher flexibility of object-oriented models, usually converge into a common architec- ture style typically known as Adaptive Object-Model (AOM) [1].
    [Show full text]