Hazelcast Jet 4.0 is released!

[Can Gencer]

Slightly delayed announcement, but I'm happy to announce that Hazelcast Jet 4.0 is released. 

You can also find a more in-depth write up on our new website: https://jet-start.sh/blog/2020/03/02/jet-40-is-released

See a summary of the new features below:

* Jet now supports calling user-defined Python function from within a

  pipeline using the mapUsingPython transform.

* Snapshots now offer support for distributed two-phase commit (2PC),

  which enables end-to-end exactly-once processing support for sinks and

  sources such as JMS and files.

* Debezium-Jet connector is now available in hazelcast-jet-contrib. The

  connector makes it possible to stream changes from a database into Jet,

  also known as Change Data Capture (CDC).

* Clients can now collect the results of jobs they have submitted via

  Rx-style Observables.

* Users can now collect custom metrics from a Pipeline, by using the Metrics class.

* The distribution has been improved with support for daemon mode and

  rolling file based logging.

* Snapshot statistics (keys & bytes saved) and job lifecycle-statistics

  (no. of jobs submitted, terminated and so on) can be tracked via

  metrics now.

* A Kafka Connect adapter is added which enables using any Kafka Connect

  source inside Jet.

* It is now possible to specify the main class when submitting jobs from

  CLI.

* Updated Hazelcast IMDG version to 4.0, which brings many new features

  such as a revamped metrics system, improved performance.