Eclipse Vert.x 4.0.0 Release Review

Vert.x 4 provides the following new important features

• Asynchronous future based programming model in addition of the asynchronous callback based model of Vert.x 3. This is an evolution that continues to provide the callback model and also provides Future returning method variants
• Support for tracing. Distributed tracing is challenging for asynchronous runtimes multiplexing several continuations on the same Java thread. Vert.x 4 provides a solution to that with an easy to support and reliable support for tracing
• HTTP client improvements that make it easier to use than before
• Improved clustering support
• Context affinity for non Vert.x thread, the same Vert.x context instance will be used when a non Vert.x thread will need to use a Context. This eliminates a kind of race conditions in user applications.
• Generic client metrics, allowing any client to report pooling and request/response metrics