4m1.md

title	date	template	author	draft
Eclipse Vert.x 4 milestone 1 released!	2019-07-26	post.html	vietj	false

We are extremely pleased to announce the first 4.0 milestone release of Eclipse Vert.x .

Vert.x 4 is the evolution of the Vert.x 3.x series that will bring key features to Vert.x.

This release aims to provide a reliable distribution of the current development of Vert.x 4 for people that want to try it and provide feedback.

Core futurisation

Vert.x 4 extends the 3.x callback asynchronous model to a future/callback hybrid model.

public interface NetClient {

  // Since 3.0
  void connect(int port, String host, Handler<AsyncResult<NetSocket>> handler);

  // New in 4.0
  Future<NetSocket> connect(int port, String host);
}

In this first milestone, only the Vert.x Core library contains the hybrid model. More Vert.x components will be futurized soon and you will be able to try them in the next milestones.

Tracing

Instrumenting asynchronous application for distributed tracing is quite challenging because most tracing libraries rely on thread local storage. While it works reasonnably well in a blocking application, this does not work for an asynchronous application.

This supposes that the application control flow matters (i.e threads) although what really matters is the application request flow (e.g the incoming HTTP request).

We improved Vert.x 4 to reify the request flow, making it possible to integrate popular tracing tools such as Zipkin or Opentracing. Vert.x performance is legendary and we made sure that this does not have any overhead out of the box (disabled).

We provide support for these two popular libraries under the Vert.x Tracing umbrella.

Groovy simplification

Groovy has been simplified in Vert.x 4 to remove any code generation.

Finally

This is the first milestone of Vert.x 4, we aim to release Vert.x 4 by the end of this year and you can of course expect more milestones to outline the progress of the effort.

The deprecations and breaking changes can be found on the wiki.

For this release there are no Docker images.,

The release artifacts have been deployed to Maven Central and you can get the distribution on Maven Central.

Most importantly the documentation has been deployed on this preview web-site https://vertx-ci.github.io/vertx-4-preview/docs/

That's it! Happy coding and see you soon on our user or dev channels.