java - Schedulers.newElastic 和 Schedulers.elastic 方法有什么区别？

Question

我正在研究 Flux 和 Mono，并在多线程环境中使用它们，并使用提供工作线程的 Schedular。

有很多选项可以使用 elastic、parallel 和 newElastic 来启动 Schedular。

这是我使用的代码:

    System.out.println("------ elastic ---------  ");
    Flux.range(1, 10)
      .map(i -> i / 2)
      .publishOn(Schedulers.elastic()).log()
      .blockLast();
    
    System.out.println("------ new elastic ---------  ");
    Flux.range(1, 10)
      .map(i -> i / 2).log()
      .publishOn(Schedulers.newElastic("my")).log()
      .blockLast();

并且他们都有相同的文档:

Scheduler that dynamically creates ExecutorService-based Workers and caches the thread pools, reusing them once the Workers have been shut down.

The maximum number of created thread pools is unbounded.

The default time-to-live for unused thread pools is 60 seconds, use the appropriate factory to push a different value.

This scheduler is not restartable.

这是他们两个的日志:

------ elastic ---------  
[ INFO] (main) | onSubscribe([Fuseable] FluxPublishOn.PublishOnSubscriber)
[ INFO] (main) | request(unbounded)
[ INFO] (elastic-2) | onNext(0)
[ INFO] (elastic-2) | onNext(1)
[ INFO] (elastic-2) | onNext(1)
[ INFO] (elastic-2) | onNext(2)
[ INFO] (elastic-2) | onNext(2)
[ INFO] (elastic-2) | onNext(3)
[ INFO] (elastic-2) | onNext(3)
[ INFO] (elastic-2) | onNext(4)
[ INFO] (elastic-2) | onNext(4)
[ INFO] (elastic-2) | onNext(5)
[ INFO] (elastic-2) | onComplete()
------ new elastic ---------  
[ INFO] (main) | onSubscribe([Fuseable] FluxMapFuseable.MapFuseableSubscriber)
[ INFO] (main) | onSubscribe([Fuseable] FluxPublishOn.PublishOnSubscriber)
[ INFO] (main) | request(unbounded)
[ INFO] (main) | request(256)
[ INFO] (main) | onNext(0)
[ INFO] (main) | onNext(1)
[ INFO] (my-4) | onNext(0)
[ INFO] (main) | onNext(1)
[ INFO] (my-4) | onNext(1)
[ INFO] (main) | onNext(2)
[ INFO] (my-4) | onNext(1)
[ INFO] (my-4) | onNext(2)
[ INFO] (main) | onNext(2)
[ INFO] (main) | onNext(3)
[ INFO] (my-4) | onNext(2)
[ INFO] (main) | onNext(3)
[ INFO] (my-4) | onNext(3)
[ INFO] (my-4) | onNext(3)
[ INFO] (main) | onNext(4)
[ INFO] (my-4) | onNext(4)
[ INFO] (main) | onNext(4)
[ INFO] (main) | onNext(5)
[ INFO] (my-4) | onNext(4)
[ INFO] (main) | onComplete()
[ INFO] (my-4) | onNext(5)
[ INFO] (my-4) | onComplete()

两者有什么区别？

Answer 1

elastic() 函数返回一个共享调度器实例。这意味着对该函数的多次调用将返回相同的调度程序。

以new 为前缀的函数将始终创建一个新的调度程序实例。

在此处检查 Scheduler 类的文档:https://projectreactor.io/docs/core/release/api/