170215 msa intro

170215 msa intro

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  1 Microservice Architecture (MSA)and Service-Oriented Architecture (SOA) Sonic Lee mcsonic@gmail.com
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  2 1 2 3 4 Service Oriented Architecture Descriptionand comparison with monolithic architecture Microservice Architecture Simple example and key characteristics MSA vs SOA Show difference in overall architecture and comm. protocol MSA Case Study: Netflix Adrian Cockcroft’s effort in turning legacy system into MSA and what we can learn
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  3 Service Oriented Architecture Definition(from Wikipedia) • Architectural pattern in computer software design in which application components provide services to other components via a communications protocol, typically over a network. Characteristics • Service is the basic building block, and is a self-contained unit of functionality. ▪ Ex: View last month’s credit card history. • Services use loosely-coupled components that can be reused later. • Components communicate using standards like JSON, XML, SOAP. • Independent of any vendor, product or technology. • Must be incremental, and built on current investments. • SOA is a means, not an end. Why? • Adapt applications to changing technologies. • Easily integrate applications with other systems. (systems are exposed) • Quickly create a business process from existing services.
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  4 Service Oriented Architecture– Four Tenets 1. Boundaries are explicit • Services interact by sending messages across boundaries. • No assumptions about how other service is made. 2. Services are autonomous • Services do not depend on other code. • Deploy and version services independently from clients. • Contracts (WSDL: Web Services Description Language) should not be changed once published. 3. Services share schema and contract, not class • Services communicate by using schema & contracts (WSDL in XML) • Internal data format should be hidden from consumers. • Public schema should be immutable. 4. Service compatibility is based upon policy • Define what (structural) and how to (semantic) communicate. • Every service provides a description of capabilities & requirements in machine code.
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  5 Before / AfterSOA App A Service AApp A DB A App A App B App C Service A
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  6 Microservice Architecture (MSA) Definition(from Martin Fowler) • Approach to developing a single application as a suite of small modular services, each running in its own process and communicating with lightweight mechanisms, often an HTTP resource API. (REST with JSON, SOAP with XML) • Each service is independently deployable by fully automated deployment machinery. Client-side [JS / HTML] Server-side [HTTP request] Relational DBMS monolith [Monolithic] Client-side [JS / HTML] Customer User DB [Microservices Architecture] Product Order Product DB Order DB API (Remote call) URL 1 URL 2 URL 3 REST RPC AMQP
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  7 Microservices: Key Characteristics •Store data in different DB for efficiency. (Polyglot persistence) • Must keep DB’s in sync. (DB structures / foreign keys) • Use Master Data Management tool to fix inconsistencies. ✓ Many RDBMSs do these checks, but require too much coupling. • Immutable Infrastructure Principle ✓ Apply changes to a new service. • Do separate build for each microservice. (OK to have different revision level files) • Servers must be interchangeable and able to scale. Treat servers like generic cows, not pets • Each microservice can use its own language / technology.
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  8 Microservices: Key Characteristics Small,cross-functional teams with flat, self / peer-management structure Can scale and innovate successfully “It’s not about technology, it’s about people.” - Asim Aslam from MicroHQ • Set up comparable teams • DevOps: respond faster to customer feedback Just using REST or Docker does not make it MSA
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  9 Microservices: Key Characteristics Product-basednot project-based • Project is a one-time development, making it hard to accumulate expertise. • De-centralized gov. model needs to guarantee developers’ career in some way. • Service team: Product planning, Development, QA, Operation. Team as suggested by Amazon
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  10 Who uses Microservices? •Netflix: https://www.nginx.com/blog/microservices-at-netflix-architectural-best- practices/ http://techblog.netflix.com/2016/12/netflix-conductor-microservices.html • Amazon: http://www.slideshare.net/apigee/i-love-apis-2015-microservices-at- amazon-54487258 • Ebay: http://www.slideshare.net/kasun04/microservices-at-ebay • Uber • Groupon • Capital One
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  11 SOA vs MicroserviceArchitecture (MSA) What is the difference? • SOA is a broader concept, and refers to architectural pattern. • Microservices is a fine-grained, more modular “ideal” type of SOA. SOA • More dependent ESBs • Imperative programming • Large relational DB MSA • API Gateways • Reactive programming • NoSQL or micro-SQL DB …But Both Share • Loosely coupled elements with bounded contexts Payment Service Cancel Service DB DB
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  12 SOA vs MSAcommunication protocol SOA ESB (Enterprise Service Bus) • Communication backbone to connect various services together. • Applications can communicate asynchronously and not have to wait. • Allows loose coupling between applications. Disadvantages • Parsing XML messages causes overhead. • ESB can become single point of failure for the network. • Often wrongly used to integrate applications. (EAI) • Vendor-driven
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  13 SOA vs MSAcommunication protocol MSA API Gateway • Smart endpoints and dumb pipes. (Most operations occur in endpoints) • REST protocols and lightweight messaging. (RabbitMQ / ZeroMQ) • Orchestration: Combine multiple services to create new ones. (Buy + membership) • Cross cutting function handling: Handle common functions. (Auth, logging)
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  14 MSA disadvantages Performance • APIcall returns results in JSON or XML. (Marshalling overhead / Network latency) Memory • Each service is deployed in its own server instance. (# of Service * memory in each) Testing • Each service is separated, so integrated testing becomes more difficult. Guaranteeing consistency may be hard • HTTP protocol is sync in nature. • Client -> Server can be sync, but internal microservice comm. must be async. 1. 202 Accepted (Tell client to wait) 2. 200 OK (Final result returned)
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  15 MSA Case Study:Netflx Netflix: Adrian Cockcroft • Key architect: moved Netflix’s own data centers to Amazon’s cloud. • Implemented public-cloud architecture & open-sourcing Netflix OSS platform. (MSA) • Changed Monolithic service to hundreds of meshed-up microservices. • Built on NGINX: Open source SW for web service, reverse proxy, cache, load balancing
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  16 MSA Case Study:Netflx Typical Reaction to Cockcorft’s Netflix talks “What Netflix is doing won’t work” – 2010 “It only works for ‘Unicorns’ like Netflix” – 2011 “We’d like to do that but can’t” – 2012 Lesson learned from time at Netflix • Speed wins in the marketplace. • High trust, low process, teams communicate with each other. • Freedom & responsibility culture. • Use simple patterns automated by tooling. • Don’t do your own “undifferentiated heavy lifting.” (특색없는 노동) • Self-service cloud makes impossible things instant.
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  17 MSA Case Study:Netflx Cockcroft’s Philosophy Common assumption: Process prevents problems (?) Organizations build up slow complex “Scar tissue” processes * Scar tissue: 반흔조직 상해되어 죽은 세포와 그 주변부의 비삼투성 보호물질로 형성된 세포로 구성된 조직. HR Rules Processes Infra Security
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  18 MSA Case Study:Process Improvement Hardware Provisioning Waterfall Product Dev IaaS (SW Provisioning) Agile Product Dev PaaS Continuous Delivery SaaSBetter
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  19 MSA Case Study:Netflx – Agile style Agile style development Email / SMS / Mobile Push / Phone call (Bit scary)
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  20 MSA Case Study:Netflx Development Cycles • 4 features / 4 weeks VS 2 features / 2 weeks Work in Progress = 4 Opportunity for bugs = 100% (baseline) Time to Debug each = 100% (baseline) Delivery Complexity = 100% (baseline) Work in Progress = 2 Opportunity for bugs = 50% (baseline) Time to Debug each = 50% (baseline) Delivery Complexity = 100 - 25 = 75%
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  21 Q&A Session Questions, comments,feedback, analysis, etc
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  22 References 1. An Introductionto Service-Oriented Architecture from a Java Developer Perspective http://archive.oreilly.com/pub/a/onjava/2005/01/26/soa-intro.html 2. Microservices - a definition of this new architectural term http://martinfowler.com/articles/microservices.html 3. What is Microservices Architecture? https://smartbear.com/learn/api-design/what-are-microservices/ 4. Service-oriented architecture (SOA) http://www.tridens.si/expertise/soa/ 5. Vivat SOA diagram http://hyperty.com/portfolio/2008/04/04/vivat-soa/ 6. Pattern: API Gateway http://microservices.io/patterns/apigateway.html 7. The introduction to Reactive Programming you've been missing https://gist.github.com/staltz/868e7e9bc2a7b8c1f754 8. Service Oriented Architecture (SOA) http://tutorials.jenkov.com/soa/soa.html
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  23 References 9. Adrian CockcroftSlideshare http://www.slideshare.net/adriancockcroft 10. How Nginx Works https://www.atulhost.com/ngin 11. Cockcroft, the Man Behind Netflix’s Move to AWS, Joins AWS http://www.datacenterknowledge.com/archives/2016/10/25/cockcroft-the-man-behind- netflixs-move-to-aws-joins-aws/ 12. Adopting Microservices at Netflix: Lessons for Architectural Design https://www.nginx.com/blog/microservices-at-netflix-architectural-best-practices/ 13. The Real Success Story of Microservices Architectures http://blog.christianposta.com/microservices/the-real-success-story-of-microservices- architectures/ 14. An Introduction to Service-Oriented Architecture from a Java Developer Perspective http://archive.oreilly.com/pub/a/onjava/2005/01/26/soa-intro.html 15. Why Companies Adopt Microservices And How They Succeed https://medium.com/microhq/why-companies-adopt-microservices-and-how-they-succeed- 2ad32f39c65a#.o6dl9bl0q