### Spring Cloud - "Umbrella Project" which consists of multiple frameworks
* Spring Cloud Connectors - Connectors to PAAS services to scale new nodes
  * Heroku
  * Cloud Foundry
* Spring Cloud Bus - Event Bus (message queue)
* Spring Cloud Netflix (= Spring Cloud Netflix Stack) - The central part of the application consists of multiple components (Provided by Netflix)
  * Archaius - Centalized configuration (like Spring Cloud Config but with Netflix technology)
  * Zuul - Proxy server with virtual paths each pointing to a specifc service which can be executed in multiple instances: Central Path Configuration so that the user doesn't recognize changes
  * Hystrix - Resilience Framework (Used with Ribbon + Feign where Hystrix is the core): A Switch that points to another instance (or throws an error when no other instance is available) when the requested instance throws an error and pauses requests to the requested instance for an amount of time (prevents deadlocks or unlimited waiting)
  * Ribbon - Load Balancer: Uses the data of Hystrix (which instance is under load based on response timings + which instance is available / not available) and provides this data to the Feign Client
  * Feign - Make REST requests easy and uses data provided by Ribbon to connect to the correct instance of that service
  * Eureka - Service Discovery: How do Hystrix + Ribbon + Feign know which service instance are available? Eureka manages service instances: Every instance introduces itself to Eureka so that Eureka can provide this information to all other participating components (liks Hystrix + Ribbon + Feign). Eureka also polls the current list of instances to unregister unavailable instances.
  * (Turbine - collects and centralize the data from Hystrix  + Eureka + etc. and provide a Turbinestream to interested components. It also comes with a Turbinedashboard where all Hystrix data is visualized)
* Spring Cloud Security - Authentication + Provide this authentication to other applications: Works with Annotations within those applications
* Spring Cloud Config - Config Server to save central configuration: prevents hard coded configs + react to changed environment
* Spring Cloud for Amazon Web Services - Integration platform: Interact with AWS services
  * SQS
  * ElastiCache
  * SNS
  * CloudFormation
  * RDS
  * SES
  * S3