UnixDomain sockets support was added in Jetty 9.4.0, back in 2015, based on the JNR UnixSocket library.

The support for UnixDomain sockets with JNR was experimental, and has remained so until now.

In Jetty 10.0.7/11.0.7 we re-implemented support for UnixDomain sockets based on JEP 380, which shipped with Java 16.

We have kept the source compatibility at Java 11 and used a little bit of Java reflection to access the new APIs introduced by JEP 380, so that Jetty 10/11 can still be built with Java 11.
However, if you run Jetty 10.0.7/11.0.7 or later with Java 16 or later, then you will be able to use UnixDomain sockets based on JEP 380.

The UnixDomain implementation from Java 16 is very stable, so we have switched our own website to use it.
The page that you are reading right now has been requested by your browser and processed on the server by Jetty using Jetty’s HttpClient to send the request via UnixDomain sockets to our local WordPress.

We have therefore deprecated the old Jetty modules based on JNR in favor of the new Jetty modules based on JEP 380.

Note that since UnixDomain sockets are an alternative to TCP network sockets, any TCP-based protocol can be carried via UnixDomain sockets: HTTP/1.1, HTTP/2 and FastCGI.

We have improved the documentation to detail how to use the new APIs introduced to support JEP 380, for the client and for the server.
If you are configuring Jetty behind a load balancer (or Apache HTTPD or Nginx) you can now use UnixDomain sockets to communicate from the load balancer to Jetty, as explained in this section of the documentation.