Hibernate goes Reactive - What Does That Mean?

 Hibernate Reactive Version 1.00 fosters non-blocking I/O access to the database plus reactive extensions. Let's get under the covers and find our why this helps.

First a definition of the problem. JPA/JDBC was always blocking, meaning that any operation that touches the database through JDBC operations will block on socket IO, and when that's happening the thread it is running on will be blocked.

So that means that when I make a call to the database from my main thread, the thread will block until the driver returns the results of the query. Then what about wrapping that call in a CompletableFuture to make the call asynchronous and wait on the Future instead, calling my callback when the database operation completes? That way don't I need a non-blocking driver after all?Perhaps, but since the stack is not non-blocking all the way down, there are certain disadvantages.

But why should the stack be non-blocking all the way down?

full article on i-programmer:

https://www.i-programmer.info/news/80-java/15025-hibernate-goes-reactive-but-what-does-that-mean.html