From Monolithic applications to Microservices
- 1. FromMonolithstoMicroservices Wikipedia Definition: Microservices are a software development technique—a variant of the service-oriented architecture (SOA) architectural stylethat structures an application as a collection ofloosely coupled services. Overview: Software world till date hasbeen dominated by monolithic applications. In short Monolithic =“Bulky applications having their components tightly coupled/dependent on eachother.” Theseapplications are alsocalled n-tier applications becausethey have n-tiers ORn-levels ORn- layers. (e.g. – 3-tier, 3- layer architecture) Companies till date have faced alot of problems with monolithic applications regarding maintenance, scalability and extensibility. In this article, we will understand how you canapply your existing knowledge of monolithic applications to dive into anew world of microservices for development of your application if you want to move someday into cloud or want tosurvive in this competitive market. Askfollowing questions to yourself: What you have now?Ans:Monolithicapplications What you want forfuture? Ans: Microservice application Whyyou want microservices?Ans:Becausewe want to take benefits of cloud technology in near / distant future. Isthere any successfulexample of microservice application?Ans:Netflix
- 2. Analogy Monolithic application Micro services Characteristics of monolithic application Singledeployable unit (E.g.– WARfile in Java,DLL/EXEor web application in .NET Consistsof multiple parts / layers. Usually3-tier applications accordingto purpose: o Database layer: Handlesall database/storage relatedoperations o Businesslogic layer: Handlesproduct specificlogic o Presentation layer: HandlesUIscreens. Deepparent-derived classhierarchy Hosted on single PCat atime. Challenges of monolithic application Troubleshooting: If afault occurs it’s difficult to pinpoint where that fault occurred becauseapplication ishuge. Scalability: If your application performance is slow you cannot scale individual parts asthese parts are heavily interconnected with other parts. Usual approachesin scalingmonolithic applications are increasing number of servers, RAM,disk space,load balancers and increasing count of VMson which these applications arehosted. New functionality canimpact whole application inabad way
- 3. Deployment: Time consuming due to repeated QAcycles and integration testing. Same technologystack: If entire application is developed in one technology stack(E.g.- .NET)then you cant switch parts of this application with another technology stack(E.g.– Java)with easeand error-freemanner. Unsuitable for cloud: BigNO-NO!!! Work of development teams need to be synchronizedwith each other w.r.t to goals. Are you fed up due to above characteristics and challenges of monolithic applications BEFORE moving intocloud? Remedy:Microservices Characteristics of microservices application Bit sizedcomponents Deployment isindependent Isolating service iseasier Canscaleasmuch asyou want without affecting other parts Canadd new functionality Chooseany technology stack of your choice Made for cloud Independent teams canhave sameor differentgoals Challenges of microservices application Number of microservices Pinpointing fault to 1 or more microservices is difficult. Oncefault is found, service canbe isolated. EmbraceDevOpsteam culture Testingis distributed and dependent on lot of independent factors. Designing with failure inmind
- 4. Synchronization of information between differentmicroservices Architectural difference between Monolithic andMicroservice application Monolithic application Micro services Factors to consider while migrating monolithic applicationto Microservice application Project deadline andbudget Technicalskillset of resources or technology stackpreference Readinessto embrace DevOpsculture Value in the eyesof customer andmanagement Readinessto deal withdistributed application architecture Ability to handle multipledevelopment teams Benefits of migrating tocloud Number/Complexity of features tobe migrated
- 5. In the next article we would see different architectural patterns for developing Microservice aplications. Please let me know your comments/suggestions.