Spring Cloud

Spring Cloud provides tools for developers to quickly build some of the common patterns in distributed systems (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). Coordination of distributed systems leads to boiler plate patterns, and using Spring Cloud developers can quickly stand up services and applications that implement those patterns. They will work well in any distributed environment, including the developer's own laptop, bare metal data centres, and managed platforms such as Cloud Foundry.

Quick Start
Fork me on GitHub

Spring Cloud builds on Spring Boot by providing a bunch of libraries that enhance the behaviour of an application when added to the classpath. You can take advantage of the basic default behaviour to get started really quickly, and then when you need to, you can configure or extend to create a custom solution.

Quick Start

The release train label (see below) is actually only used explicitly in one artifact: "spring-cloud-dependencies" (all the others have normal numeric release labels tied to their parent project). The depednencies POM is the one you can use as a BOM for dependency management. Example using the latest version with the config client and eureka (change the artifact ids to pull in other starters):

Download

The recommended way to get started using spring-cloud in your project is with a dependency management system – the snippet below can be copied and pasted into your build. Need help? See our getting started guides on building with Maven and Gradle.

Features

Spring Cloud focuses on providing good out of box experience for typical use cases and extensibility mechanism to cover others.

  • Distributed/versioned configuration
  • Service registration and discovery
  • Routing
  • Service-to-service calls
  • Load balancing
  • Circuit Breakers
  • Global locks
  • Leadership election and cluster state
  • Distributed messaging

Spring Cloud takes a very declarative approach, and often you get a lot of fetaures with just a classpath change and/or an annotation. Example application that is a discovery client:

@SpringBootApplication
@EnableDiscoveryClient
public class Application {
	public static void main(String[] args) {
		SpringApplication.run(Application.class, args);
	}
}

Main Projects

Spring Cloud Config

Centralized external configuration management backed by a git repository. The configuration resources map directly to Spring `Environment` but could be used by non-Spring applications if desired.

Spring Cloud Netflix

Integration with various Netflix OSS components (Eureka, Hystrix, Zuul, Archaius, etc.).

Spring Cloud Bus

An event bus for linking services and service instances together with distributed messaging. Useful for propagating state changes across a cluster (e.g. config change events).

Spring Cloud for Cloud Foundry

Integrates your application with Pivotal Cloudfoundry. Provides a service discovery implementation and also makes it easy to implement SSO and OAuth2 protected resources, and also to create a Cloudfoundry service broker.

Spring Cloud Cloud Foundry Service Broker

Provides a starting point for building a service broker that manages a Cloud Foundry managed service.

Spring Cloud Cluster

Leadership election and common stateful patterns with an abstraction and implementation for Zookeeper, Redis, Hazelcast, Consul.

Spring Cloud Consul

Service discovery and configuration management with Hashicorp Consul.

Spring Cloud Security

Provides support for load-balanced OAuth2 rest client and authentication header relays in a Zuul proxy.

Spring Cloud Sleuth

Distributed tracing for Spring Cloud applications, compatible with Zipkin, HTrace and log-based (e.g. ELK) tracing.

Spring Cloud Data Flow

A cloud native programming and operating model for composable data microservices on a structured platform.

Spring Cloud Stream

Messaging microservices with Redis, Rabbit or Kafka. Simple declarative model to send and receive messages in a Spring Cloud app.

Spring Cloud Stream Modules

Spring Cloud Stream Modules can be used with Spring Cloud Stream to create, build, and scale message-driven data microservices.

Spring Cloud Task

Short lived microservices. Simple declarative for adding both functional and non-functional features to Spring Boot apps.

Spring Cloud Zookeeper

Service discovery and configuration management with Apache Zookeeper.

Spring Cloud for Amazon Web Services

Easy integration with hosted Amazon Web Services. It offers a convenient way to interact with AWS provided services using well-known Spring idioms and APIs, such as the messaging or caching API. Developers can build their application around the hosted services without having to care about infrastructure or maintenance.

Spring Cloud Connectors

Makes it easy for PaaS applications in a variety of platforms to connect to backend services like databases and message brokers (the project formerly known as "Spring Cloud").

Spring Cloud Starters

Spring Boot-style starter projects to ease dependency management for consumers of Spring Cloud. (Discontinued as a project and merged with the other projects after Angel.SR2.)

Spring Cloud CLI

Spring Boot CLI plugin for creating Spring Cloud component applications quickly in Groovy

Release Trains

Spring Cloud is an umbrella project consisting of independent projects with, in principle, different release cadences. To manage the portfolio a BOM (Bill of Materials) is published with a curated set of dependencies on the individual project (see below). The release trains have names, not versions, to avoid confusion with the sub-projects. The names are an alphabetic sequence (so you can sort them chronologically) with names of London Tube stations ("Angel" is the first release, "Brixton" is the second). When point releases of the individual projects accumulate to a critical mass, or if there is a critical bug in one of them that needs to be available to everyone, the release train will push out "service releases" with names ending ".SRX", where "X" is a number.

Release train contents:

Component Angel.SR6 Brixton.SR5 Camden.M1 Camden.BUILD-SNAPSHOT
spring-cloud-aws 1.0.4.RELEASE 1.1.1.RELEASE 1.1.1.RELEASE 1.1.2.BUILD-SNAPSHOT
spring-cloud-bus 1.0.3.RELEASE 1.1.1.RELEASE 1.2.0.M1 1.2.0.BUILD-SNAPSHOT
spring-cloud-cli 1.0.6.RELEASE 1.1.5.RELEASE 1.2.0.M1 1.2.0.BUILD-SNAPSHOT
spring-cloud-commons 1.0.5.RELEASE 1.1.1.RELEASE 1.1.1.RELEASE 1.1.2.BUILD-SNAPSHOT
spring-cloud-contract     1.0.0.M2 1.0.0.BUILD-SNAPSHOT
spring-cloud-config 1.0.4.RELEASE 1.1.3.RELEASE 1.2.0.M1 1.2.0.BUILD-SNAPSHOT
spring-cloud-netflix 1.0.7.RELEASE 1.1.5.RELEASE 1.2.0.M1 1.2.0.BUILD-SNAPSHOT
spring-cloud-security 1.0.3.RELEASE 1.1.2.RELEASE 1.1.2.RELEASE 1.1.3.BUILD-SNAPSHOT
spring-cloud-starters 1.0.6.RELEASE      
spring-cloud-cloudfoundry   1.0.0.RELEASE 1.0.0.RELEASE 1.0.1.BUILD-SNAPSHOT
spring-cloud-cluster   1.0.1.RELEASE    
spring-cloud-consul   1.0.2.RELEASE 1.1.0.M1 1.1.0.BUILD-SNAPSHOT
spring-cloud-sleuth   1.0.6.RELEASE 1.0.6.RELEASE 1.0.7.BUILD-SNAPSHOT
spring-cloud-stream   1.0.2.RELEASE Brooklyn.M1 Brooklyn.BUILD-SNAPSHOT
spring-cloud-zookeeper   1.0.2.RELEASE 1.0.2.RELEASE 1.0.3.BUILD-SNAPSHOT
spring-boot 1.2.8.RELEASE 1.3.7.RELEASE 1.4.0.RELEASE 1.4.0.RELEASE
spring-cloud-task   1.0.2.RELEASE 1.0.2.RELEASE 1.0.3.BUILD-SNAPSHOT

The Brixton release train builds on Spring Boot 1.3.x, but is also tested with 1.4.x.

The Angel release train builds on Spring Boot 1.2.x, and is incompatible in some areas with Spring Boot 1.3.x. Brixton builds on Spring Boot 1.3.x and is similarly incompatible with 1.2.x. Some libraries and most apps built on Angel will run fine on Brixton, but changes will be required anywhere that the OAuth2 features from spring-cloud-security 1.0.x are used (they were mostly moved to Spring Boot in 1.3.0).

Use your dependency management tools to control the version. If you are using Maven remember that the first version declared wins, so declare the BOMs in order, with the first one usually being the most recent (e.g. if you want to use Spring Boot 1.3.6 with Brixton.RELEASE, put the Boot BOM first). The same rule applies to Gradle if you use the Spring dependency management plugin.

NOTE: starting after Brixton.M4 the release train contains a spring-cloud-starter-dependencies as well as the spring-cloud-starter-parent. Use the parent as you would the spring-boot-starter-parent (if you are using Maven). If you only need dependency management, the "dependencies" version is a BOM-only version of the same thing (it just contains dependency management and no plugin declarations or direct references to Spring or Spring Boot). If you are using the Spring Boot parent POM, then you can use the BOM from Spring Cloud.