Spring Cloud Framework

Spring Cloud Framework

Spring Cloud Config

Spring Cloud is a framework for developing robust cloud applications. It’s designed to solve “the data access problem” that arises because cloud applications will typically use external systems like a database or IoT platform. So, the framework handles connection pooling and failover, routing and load balancing, message-based interactions with microservices, RESTful HTTP support, and circuit breakers to manage distributed systems’ errors. It also has a Spring Boot starter module to add cloud capabilities to Spring Boot applications.

Spring Cloud supports anything running on the JVM, including Java and Kotlin. The Spring Cloud modules make Spring Boot more cloud-ready by providing out-of-the-box support for AWS, IBM Bluemix, Microsoft Azure, and Google Cloud Platform. Spring Cloud also integrates with a raft of other open-source projects. This means greater ecosystem portability is possible, particularly useful when dealing with critical business applications.

Free Spring Cloud Certification Practice Test

Spring Cloud Gateway SSE

Server Sent Events (SSE) is an HTTP standard that enables a web application to manage a unidirectional event stream and receive changes anytime the server emits data. This is especially useful when implementing pub-sub. It can significantly reduce the number of hops your web app needs to make and improve overall scalability. An SSE is a standard that most browsers use to enable unidirectional streaming of events at any time.  The “events” are just a stream of UTF-8 encoded text data that adheres to the specification’s format.  The “server” is just a web server that emits data in SSE format.

Spring Cloud Kubernetes

Spring Cloud Kubernetes offers Spring Cloud interface implementations, enabling developers to develop and operate Spring Cloud applications on Kubernetes. It does this by leveraging Kubernetes APIs to expose the Spring Cloud PaaS. It is built on top of the Kubernetes open-source ecosystem and uses a configuration-driven approach to integrate with other Kubernetes components, such as Kubernetes Dashboard and Heapster. This implementation also uses the Fabric8 client library to bring Kubernetes features to the Spring Cloud field.

Spring Cloud OpenFeign

OpenFeign is an open-source client library that assists developers in constructing HTTP clients declaratively by using annotated interfaces rather than writing boilerplate code. It includes a complete implementation of Http client and various tools for extracting information from responses such as Headers, Cookies, and Parameters. Spring Cloud OpenFeign is more than simply an HTTP client; it offers a solution to challenges associated with contemporary REST clients. OpenFeign’s flexibility and functionality reduce the cost of developing a client while supporting contemporary complicated HTTP APIs.

Spring Cloud Bus

Spring Cloud Bus connects distributed system nodes to a lightweight message broker. It solves the problem of message routing by providing a lightweight and reliable service. Spring Cloud Bus is currently in the Beta phase, but the product will reach release candidate status soon. Spring Cloud Bus can be easily deployed with docker containers, has built-in discovery and load balancing support by the HTTP load balancer, and supports JDBC data source.

Spring Cloud Bus is an open-source project that enables users to write distributed applications on top of the Spring Boot framework. It provides useful features such as asynchronous message routing, reliable messaging service with support for transactions, easy integration with other enterprise systems such as CMDB, and configuration management tools like Chef or Puppet.

Spring Cloud Connector

Spring Cloud Connectors is a project that makes it easier to link Spring applications to cloud platform services and obtain operational knowledge of those platforms. Its main purpose is to provide connector SDKs for all the major cloud platforms, such as Google App Engine, Amazon Web Services, and Azure. Spring Cloud Connectors is driven by the need for a developer platform that can be quickly and easily extended without having to design from scratch. It empowers developers by letting them focus on the logic required to build their applications instead of spending time designing and implementing a generic API bridge.

Spring Cloud Gateway Load Balancer

The Spring Cloud Load Balancer package enables us to design apps that connect with other apps in a load-balanced manner. The LoadBalancer is implemented as a Spring Cloud Gateway, which exposes the application’s RESTful interface to the load balancer. The load balancer can be used to balance the load between multiple instances of your application. If you want to add fault tolerance, you can deploy two copies of your application and point a LoadBalancer at them. When one instance fails, the LoadBalancer will immediately switch to the other instance.

Spring Cloud Gateway

Spring Cloud Maven

The Spring Cloud Maven plugin integrates a Maven build with the Spring Boot CLI. It is designed to execute Maven builds in a local multi-project build on your machine and execute them in the cloud. This plugin also allows you to have Maven projects built and tested by CI servers such as Jenkins while not interrupting the flow of your normal build process.

The Spring Cloud Maven plugin enables you to handle different projects, multiple environments, and tasks during a single build. With this plugin, you can run your machine locally while automatically executing tests on a CI server without interrupting your build. The plugin allows you to configure the dependencies and test goals used to determine which set of tests to run and how to handle those tests.

Spring Cloud Starter Vault Config

Spring Cloud Vault Config offers client-side support for externalized configuration in a distributed system. It is built as a library to be used by any of your Spring Cloud projects. Using Spring Cloud Vault Config, you can easily add a service discovery layer that provides provenance and auditing capabilities for your services without managing yet another infrastructure service. This is another great tool to add to your growing spring boot toolkit. The Vault Config server allows you to store configuration data in a secure, centralized, and auditable manner using Amazon’s AWS VPC (Virtual Private Cloud). Configuration data can then be dynamically retrieved by Spring applications using the Spring Cloud Vault client library. The client library can fetch configuration details on a per-request basis without exposing your credentials or other sensitive information.

Difference between Spring Cloud and Spring Boot

Spring Boot is an open-source framework for developing microservices in the Java programming language. Spring Cloud, on the other hand, is used to maintain micro-service settings. It stores all the information about the microservice in a cloud. In the below table, we can see some of the differences between Spring Boot and Spring Cloud:

                                   Spring Cloud

                                Spring Boot

It includes an open-source library

It includes an open-source library

It maintains microservice configuration

It develops microservices.

It has the potential to seek services intelligently

Call a static () run function to generate static spring programs

It set up and delivered messages

It handles the listers and events on its own

Load balance is used to create network traffic in back-end services

It has basic authentication for security

Spring Cloud Azure Functions

Azure Functions is an on-demand cloud solution offering constantly updated infrastructure and resources required to execute your apps. Developers can use Azure Functions to trigger activity in response to events happening in the cloud, on devices, or on-premises with an API. The simplest approach to utilize it with Spring Cloud is to extend a base class and put away in it with the @FunctionName annotation, which delegates to a base class function. The advantage here is that you can run your function directly from Azure and when using Azure CLI commands. At this point, developers will be comfortable with how functions are executed here. As an occurrence, it is up to you to start with a base class with method attributes that match the information you want to send.

Spring Cloud Config Client Refresh

When using Spring Cloud Config Server, Spring Cloud provides many ways to refresh config clients’ properties.

  • Calling the /actuator/refresh endpoint provided on the config client through the Spring Actuator.
  • Calling the /actuator/bus-refresh endpoint accessible on the Spring Cloud Bus configuration client.
  • Calling the /monitor endpoint on the Spring Cloud Bus configuration server.

Spring Cloud Config Server Security

The configuration server must be kept secure since it may include sensitive configuration information such as access credentials to other apps and services. This is especially crucial in cloud environments, where multiple pods of applications may be running and sharing information. If the configuration server is compromised, it could lead to data breaches that compromise the security of a system or organization. The following are some basic but effective techniques for increasing the security of the configuration server.

  • When sending configurations, always use secure channels.
  • Disable encryption on the cloud configuration server.
  • Passwords should never be stored in plain text.
  • Use authentication on the configuration server.
  • As a configuration source, use a secure, private repository.

Spring Cloud Config Server JDBC

JDBC is supported as a backend for configuration properties by Spring Cloud Config Server. This allows for simple configuration properties used for other purposes, referential integrity, storing values in different databases, reading values from other systems, or simply storing string values as unique identifiers. The configuration properties are distributed to all server instances so that the same property can be used across multiple projects. You may activate this feature by including spring-jdbc on the classpath and utilizing the JDBC profile or by including a JdbcEnvironmentRepository bean.

Spring Cloud Question and Answers

A framework for creating reliable cloud applications is called Spring Cloud. By offering solutions to many of the usual issues encountered when switching to a distributed environment, the framework makes it easier to design applications.

A method offered by Spring Cloud involves storing all of the microservice configurations across all environments in a Git repository. All of the microservices are then given access to this data by the Spring Cloud Config Server.

A framework for creating highly scalable, event-driven microservices linked to shared messaging systems is called Spring Cloud Stream. The components offered by Spring Cloud Stream abstract away from the code the interaction with numerous message brokers.

Developers may quickly create some of the prevalent patterns in distributed systems using the tools provided by Spring Cloud (e.g. configuration management, service discovery, circuit breakers, intelligent routing, micro-proxy, control bus, one-time tokens, global locks, leadership election, distributed sessions, cluster state).

An open-source project called Spring Cloud Azure enables easy Spring integration with Azure services. With just a few lines of configuration code and minimal code changes, it provides developers with a Spring-idiomatic approach to connect to and use Azure services.

For externalized configuration in a distributed system, Spring Cloud Config offers server-side and client-side support. You have a central location to control external properties for applications across all environments with the Config Server. They match perfectly with Spring applications but can be used with any application running in any language because the notions on both the client and the server map exactly to the Spring Environment and PropertySource abstractions.

The Consumer Driven Contracts strategy can be successfully implemented by users thanks to the solutions offered by the Spring Cloud Contract umbrella project. The Spring Cloud Contract Verifier project is all that is available for now for Spring Cloud Contract.

Tools are available in Spring Cloud Data Flow to build intricate topologies for batch and streaming data pipelines. Spring Boot programs created with the Spring Cloud Stream or Spring Cloud Task microservice frameworks make up the data pipelines.

A library for creating API gateways on top of Spring and Java is offered by Spring Cloud Gateway. It focuses on cross-cutting issues like security, robustness, and monitoring and offers a flexible mechanism to route requests based on a variety of factors.

For storing and serving distributed configurations across many applications and contexts, Spring uses a client/server technique called Spring Cloud Config. This configuration store can be changed during program runtime and is ideally versioned under Git version control.

  • Spring Cloud config offers client-side and server support for different distributed system configurations. 
  • It offers a central platform to handle distinct attributes for all apps across multiple contexts. 
  • The idea maps for the Property Source abstractions and Spring applications are the same for both the server and the client. 
  • They can be used with any apps in any language and are compatible with Spring applications.
  • When applications are being deployed across pipelines from development to testing, it enables you to manage and customize every environment. 
  • It also ensures that when an application migrates, all of its requirements are met.
  • Spring Cloud Config makes it simple to create and integrate different implementations.

A lightweight message broker called Spring Cloud Bus connects the nodes in a distributed system. Then, you may utilize this to broadcast management directives or state changes (such configuration updates). The project includes AMQP and Kafka broker implementations.

Making standalone, professional Spring-based applications that you can “simply launch” is simple using Spring Boot.
In order to help you get started quickly, we take an opinionated stance on the Spring platform and third-party libraries. Spring setup is typically not necessary for Spring Boot apps.

Through autoconfiguration, binding to the Spring Environment, and other Spring programming model idioms, Spring Cloud Netflix offers Netflix OSS connectors for Spring Boot projects.

Netflix’s Zuul is a server side load balancer and router built on the JVM. Additionally, Spring Cloud integrates well with an embedded Zuul proxy.

A framework for creating dependable cloud applications, Spring Cloud offers a solution to the patterns that are frequently faced when creating distributed systems. Developers may quickly create cloud apps and microservices-based applications with the help of the Spring Cloud framework.

The Circuit Breaker pattern is implemented by the Spring Cloud Circuit Breaker library: when we wrap a method call in a circuit breaker, Spring Cloud Circuit Breaker monitors for failing calls to that method and, if failures reach a threshold, opens the circuit to cause subsequent calls to fail automatically.

Open application Platform as a Service (PaaS) Cloud Foundry was created under an open source license. In other words, Cloud Foundry is a platform that enables the rapid deployment, management, and scaling of stateless applications created in any programming language or framework.

As requests go via a distributed software system, Spring Cloud Sleuth enables you to aggregate and track log data. Because all requests can easily be logged to the same log file, it is extremely simple to trace requests as they progress through the codebase in a monolithic system.

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