如何為期貨配置微調的線程池？

Question

Scala 的期貨線程池有多大？

我的 Scala 應用程序生成了數百萬個future {} ，我想知道我是否可以通過配置線程池來優化它們。

謝謝你。

Answer 1

這個答案來自monkjack，來自已接受答案的評論。 然而，人們可能會錯過這個很好的答案，所以我在這里重新發布。

implicit val ec = ExecutionContext.fromExecutor(Executors.newFixedThreadPool(10))

如果只需要更改線程池計數，只需使用全局執行器並傳遞以下系統屬性即可。

-Dscala.concurrent.context.numThreads=8 -Dscala.concurrent.context.maxThreads=8

Answer 2

您可以指定自己的期貨將在其中運行的 ExecutionContext，而不是導入全局隱式 ExecutionContext。

import java.util.concurrent.Executors
import scala.concurrent._

implicit val ec = new ExecutionContext {
    val threadPool = Executors.newFixedThreadPool(1000)

    def execute(runnable: Runnable) {
        threadPool.submit(runnable)
    }

    def reportFailure(t: Throwable) {}
}

Answer 3

在 Scala 期貨中指定線程池的最佳方法：

implicit val ec = new ExecutionContext {
      val threadPool = Executors.newFixedThreadPool(conf.getInt("5"));
      override def reportFailure(cause: Throwable): Unit = {};
      override def execute(runnable: Runnable): Unit = threadPool.submit(runnable);
      def shutdown() = threadPool.shutdown();
    }

Answer 4

class ThreadPoolExecutionContext(val executionContext: ExecutionContext)

object ThreadPoolExecutionContext {

  val executionContextProvider: ThreadPoolExecutionContext = {
    try {
      val executionContextExecutor: ExecutionContextExecutor = ExecutionContext.fromExecutor(Executors.newFixedThreadPool(25))
      new ThreadPoolExecutionContext(executionContextExecutor)
    } catch {
      case exception: Exception => {
        Log.error("Failed to create thread pool", exception)
        throw exception
      }
    }
  }
}