anchor.diff:  `Couchbase` is document oriented database and distributed by design that meets the scalability requirements of `Reactivity`.
   This database also provides additional interesting products like embedded database for mobile that can be leveraged to cover new features.
   This is why our primary choice goes for `Couchbase` server to store the data of `Reactivity`.
  +
  +Since a `JSON` document data model can be easily extended by addibg more properties to it, `Couchbase` also offers the opportunity to dynamically add extensions to `Reactivity`.
   
   == Components architecture view
   
  
positive.code: In case of unexpected desynchronization (typically a state that is expected to be synchronized regarding the messages that are delivered and those who are not), a re-initialization of that data should be possible.
  Message streaming should be used as much as possible to replicate a data from scratch, including transformations process.
  
  == Key technologies
  
  === Based on OSS
  
negative.code: ==== Web application
  
  The web application consumes `SSE` streams from the back-end.
  It also pushes new messages to the `Kafka` service to be validated asynchronously by `Reactivity`.
  
  === Extensions
  
  Extensions are playing the role of additional API.
  Recommended technology for their implementation is `Spring Boot` but it's not mandatory.
  However, an extension must follow the standards defined by `Reactivity` architecture:
  
  * A micro service that registers to `ZooKeeper`
  * Consumes data through `Kafka` connectors
  * Persist data to `Couchbase` and send notification through `Kafka`
  
  Additional statics (`JS`, `CSS`, `HTML`) can be also served to the web application in order to extend the user experience of `Reactivity`.