Fire and forget with reactor

Question

I have a method like below in my Spring boot app.

public Flux search(SearchRequest request) {
  Flux<         


        

Answer 1

Have you considered running the processing in separate threads using publishOn like in the example below? This may not be exactly what you are asking for but allows you to continue with other matters while the processing of the results in the flux is done by one or more threads, four in my example, from a dedicated scheduler (theFourThreadScheduler).

    @Test
    public void processingInSeparateThreadTest() {
        final Scheduler theFourThreadScheduler = Schedulers.newParallel("FourThreads", 4);
        final Flux theResultFlux = Flux.just("one", "two", "three", "four", "five", "six", "seven", "eight");

        theResultFlux.log()
            .collectList()
            .publishOn(theFourThreadScheduler)
            .subscribe(theStringList -> {
                doThisAsync(theStringList);
            });

        System.out.println("Subscribed to the result flux");

        for (int i = 0; i < 20; i++) {
            System.out.println("Waiting for completion: " + i);
            try {
                Thread.sleep(300);
            } catch (final InterruptedException theException) {
            }
        }
    }

    private void doThisAsync(final List inStringList) {
        for (final String theString : inStringList) {
            System.out.println("Processing in doThisAsync: " + theString);
            try {
                Thread.sleep(500);
            } catch (final InterruptedException theException) {
            }
        }
    }

Running the example produce the following output, showing that the processing performed in doThisAsync() is performed in the background.

Subscribed to the result flux
Waiting for completion: 0
Processing in doThisAsync: one
Waiting for completion: 1
Processing in doThisAsync: two
Waiting for completion: 2
Waiting for completion: 3
Processing in doThisAsync: three
Waiting for completion: 4
Waiting for completion: 5
Processing in doThisAsync: four
Waiting for completion: 6
Processing in doThisAsync: five
Waiting for completion: 7
Waiting for completion: 8
Processing in doThisAsync: six
Waiting for completion: 9
Processing in doThisAsync: seven
Waiting for completion: 10
Waiting for completion: 11
Processing in doThisAsync: eight
Waiting for completion: 12
Waiting for completion: 13
Waiting for completion: 14
Waiting for completion: 15
Waiting for completion: 16
Waiting for completion: 17
Waiting for completion: 18
Waiting for completion: 19

References: Reactor 3 Reference: Schedulers