최신 파이썬 버전은 **“코루틴”**이라고 하는 것을 사용하는 **“비동기 코드”**를 **`async` 및 `await`** 문법과 함께 지원합니다.

아래 섹션들에서 해당 문장을 부분별로 살펴보겠습니다:

* **비동기 코드**
* **`async`와 `await`**
* **코루틴**

## 비동기 코드 { #asynchronous-code }

비동기 코드는 언어 💬 가 코드의 어느 한 부분에서 컴퓨터/프로그램 🤖 에게, 어느 시점에는 어딘가에서 *다른 무언가*가 끝날 때까지 기다려야 한다고 말할 수 있는 방법이 있다는 의미입니다. 그 *다른 무언가*를 "slow-file" 📝 이라고 해보겠습니다.

따라서 그 시간 동안 컴퓨터는 "slow-file" 📝 이 끝나는 동안 다른 작업을 하러 갈 수 있습니다.

import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicReference;
import org.jspecify.annotations.Nullable;

/**
 * Serializes execution of tasks, somewhat like an "asynchronous {@code synchronized} block." Each
 * {@linkplain #submit enqueued} callable will not be submitted to its associated executor until the

**Solution**:
- Split large files into smaller batches (e.g., 10,000 docs per file)
- Increase timeout in `system.properties`:
  ```properties
  crawler.document.request.timeout=600000
  ```
- Use asynchronous import via Admin UI instead of API

#### Issue: Special characters in documents not displaying correctly

**Solution**:
- Ensure source files are UTF-8 encoded
- Check `fess_config.properties`:

  /** http://tools.ietf.org/html/draft-ietf-httpbis-http2-17#section-5.1.1 */
  internal var nextStreamId = if (builder.client) 3 else 2

  private var isShutdown = false

  /** For scheduling everything asynchronous. */
  private val taskRunner = builder.taskRunner

  /** Asynchronously writes frames to the outgoing socket. */
  private val writerQueue = taskRunner.newQueue()

モダンな Python は **「非同期コード」** を **「コルーチン」** と呼ばれる仕組みでサポートしており、構文は **`async` と `await`** です。

以下のセクションで、このフレーズをパーツごとに見ていきます:

* **非同期コード**
* **`async` と `await`**
* **コルーチン**

## 非同期コード { #asynchronous-code }

非同期コードとは、言語 💬 がコードのどこかの時点で、コンピュータ/プログラム 🤖 に「どこか別のところで終わるまで、別の何か」を待つ必要があると伝える手段を持っている、ということです。その「別の何か」を「遅いファイル」📝 と呼ぶことにしましょう。

その間、コンピュータは「遅いファイル」📝 が終わるまで、他の作業を進められます。

  val directory: Path,
  private val appVersion: Int,
  internal val valueCount: Int,
  /** Returns the maximum number of bytes that this cache should use to store its data. */
  maxSize: Long,
  /** Used for asynchronous journal rebuilds. */
  taskRunner: TaskRunner,
) : Closeable,
  Flushable,
  Lockable {
  internal val fileSystem: FileSystem =
    object : ForwardingFileSystem(fileSystem) {
      override fun sink(

streaming                         (on|off)    set to 'on', to use streaming NATS server
streaming_async                   (on|off)    set to 'on', to enable asynchronous publish
streaming_max_pub_acks_in_flight  (number)    number of messages to publish without waiting for ACKs
streaming_cluster_id              (string)    unique ID for NATS streaming cluster

- Disabled the `SchedulerAsyncAPICalls` feature gate to mitigate a bug where its interaction with asynchronous preemption could degrade `kube-scheduler` performance, especially under high `kube-apiserver` load. ([#134400](https://github.com/kubernetes/kubernetes/pull/134400), [@macsko](https://github.com/macsko))

      this.routeDatabase = okHttpClient.routeDatabase
      this.taskRunner = okHttpClient.taskRunner
    }

    /**
     * Sets the dispatcher used to set policy and execute asynchronous requests. Must not be null.
     */
    fun dispatcher(dispatcher: Dispatcher) =
      apply {
        this.dispatcher = dispatcher
      }

    /**

 * article on <a href="https://github.com/google/guava/wiki/ListenableFutureExplained">{@code
 * ListenableFuture}</a>.
 *
 * <p>The main purpose of {@code ListenableFuture} is to help you chain together a graph of
 * asynchronous operations. You can chain them together manually with calls to methods like {@link
 * Futures#transform(ListenableFuture, Function, Executor) Futures.transform}, but you will often