Representational State Transfer REST architectural constraints скачать в хорошем качестве

Representational State Transfer REST architectural constraints

REST API Architectural Constraints Overview What is REST Representational State Transfer Architecture style Set of rules for creating web services. Using HTTP Protocol for communication Uniform Predefined rule Server - Own Resource Client - Request Resource Architectural Constraints Uniform Interface Stateless Cacheable Client-Server Layered System Code on Demand (Optional) Uniform Interface Rest is a client server model and client should have the ability to interact with server in a consistent and predictable way. Resource based - Eg - Users, Books (URL should be based on that) Standardized methods - GET, POST, PUT, DELETE Stateless Self Describing Response - Details about content HATEOAS - further actions url Stateless No Server Side Memory Self Contained Requests Benefits of Statelessness Scalability Simplicity Reliability Flexibility How to overcome Stateless Authentication Token Cookies (No ideal) Self Describing Messages Client understand server response without prior knowledge about the service Clarity Without Confusion Content Type (JSON/XML), Status Code(200, 201), Headers (Additional info), Payload(Optional) Reduced Coupling, Interoperability, Easier maintenance Additional - Media Type, Documentation (Swagger) HATEOAS (Hypermedia as the Engine of Application State) Client Driven Navigation, Reduced Coupling, Flexibility How - Hypermedia Links, Content Type, Status Code Benefits - Reduced Complexity, Improved maintainability, Discoverability Drawbacks - Initial learning curve, complex response Cacheable Client Side Caching - Client application can cache Server Side Caching - in memory cache and dedicated cache Cache Invalidation - cache expiration Cacheability in REST Responses (Server can control client caching) Cache Control - no-cache or no-store to prevent caching entirely. Expires Benefits Improved Performance Reduced Server load Increase Scalability Enhanced User Experience Designing Cacheable REST API Identify Resources that are frequently access and relatively static Set appropriate cache expiration time Mechanism to invalidate cache if resource updated Client-Server Separation of Concerns b/w Client and Server Independent Evolution Well Defined interface (Resources/Standard methods) Statelessness Benefits of Client-Server Constraints Scalability Simplicity Interoperability Layered System REST api communication can be broken down into distinct layers Architecture divided into distinct layers, each with different functionality Intermediate services b/w client and server Caching Security Load balancing Transparency - Client not need to aware Code On Demand (Optional) Server provide a code that client can execute Encryption Custom Rendering