Eclipse Ditto 1.1.0
The first minor release of Eclipse Ditto 1.x will focus on the following topics/enhancements:
- Addition of MQTT 5 connectivity
- Enriching emitted Ditto messages (e.g. twin events, live messages) with extra fields from the thing
- Support for policies in Ditto Protocol and in Ditto Java client
- Support for search in Ditto Protocol and in Ditto Java client
- Run Ditto services with Java 11
- First steps towards end-2-end acknowledgements handled by Ditto:
Model implementations which Ditto 1.2.0 will use in order to e.g. settle/acknowledge received messages over protocols supporting that, based on the successful application of a received message to the Ditto persistence or even to other external subscribers.
This will enable QoS 1 (at least once) processing of messages from connection protocols supporting different quality of services (e.g. AMQP, MQTT).
The project leadership certifies that the APIs in this release are "Eclipse Quality".
Ditto's codebase is implemented in Java. By default Java objects are mutable which does not work well in highly scalable, message driven architectures, as possible side-effects during runtime may occur when concurrently modifying objects. Because of that the Ditto team decided to use immutable objects wherever and whenever possible. Immutablity of the objects is ensured in unit tests.
Ditto's model modules and also the Ditto Java client are OSGi bundles so that they may be used in OSGi environments without much effort. The model modules are configured to be checked by a "binary compatibility checker" in the Maven build so that APIs are not broken unintentionally.
On a level higher than the model, Ditto uses a microservice based architecture. As Ditto's microservices are interacting via an event driven approach, Ditto provides a very modular setup on the microservice level meaning that single services must be not started at all if their functionality is not needed. Another benefit from this architecture is that the services may be scaled horizontally if more resources are required.
Ditto utilizes the CQRS and EventSourcing pattern and mainly uses "inserts" (append only) into the database in favor to "updates" in order to get a better performance when doing database writes. The only exception is the "search" microservice which uses traditional CRUD in order to update its search index.
There are no security issues known at the time of this writing.
Ditto comes with:
- A project site containing the documentation (including basic concepts, architecture, definition of the Ditto Protocol, etc.)
- A "Hello World" example
- An OpenAPI based HTTP/REST documentation and applied HTTP concepts
- A GitHub repository with ditto-examples
- A Blog with the latest examples tutorials, release announcements, etc.
- Presentations of Ditto
- A sandbox installation where Ditto can be tried out without setting it up locally
Ditto does not provide a UI yet.
Deprecation of API version 1
Starting with Ditto 1.1.0, usage of the API in version 1 (e.g. contained in HTTP URLs as /api/1/things...) is deprecated.
API version 1 and ACLs will very likely be removed in Ditto 2.0.
Ditto is able to process AMQP 1.0, AMQP 0.9.1, MQTT 3.1.1 and MQTT 5 messages which are all standardized (IoT) protocols.
Ditto can use JSON Web Tokens specified by RFC 7519 in order to extract "subjects" (e.g. a user-id) to use for the access control to twins.
Ditto's API documentation is defined using the OpenAPI specification 3.0.0 allowing both creation of an interactive HTML-based documentation and creation of skelettons for various programming languages based on that specification.
The Ditto team is active on meetups, conferences (giving talks), blogs and social media in order to gain visibility in the community.
Users of Ditto ask their questions via these channels:
- The Gitter chatroom of Ditto
- Directly via GitHub issues (the Ditto teams labels with "question")
- A Stackoverflow tag "eclipse-ditto" on which community quersions are answered by our committers
- The mailing-list (email@example.com) contains mainly administrational topics regarding the Ditto project
Ditto seeks for a good integration with Eclipse Hono in order to being able to create digital twins for all devices connected via Hono. The Ditto team is also in regular discussion with the Hono team.
Some of the Ditto team are committers in the Eclipse IoT Packages project aiming to simplify deployment and integration between Eclipse Hono, Ditto and hawkBit in the first step.