/// tip

先別擔心這裡提到的「容器」、Docker 或 Kubernetes 如果現在還不太懂。

我會在未來的章節進一步說明容器映像、Docker、Kubernetes 等等：[容器中的 FastAPI - Docker](docker.md)。

///

## 啟動前的前置步驟 { #previous-steps-before-starting }

很多情況下，你會希望在應用「啟動之前」先執行一些步驟。

例如，你可能想先執行「資料庫遷移」。

但在多數情況下，你會希望這些步驟只執行「一次」。

所以，你會希望用「單一行程」來執行那些「前置步驟」，在啟動應用之前完成。

    /**
     * Default constructor.
     */
    public CoordinatorHelper() {
        // Default constructor
    }

    /**
     * Initializes the coordinator by sending an initial heartbeat and starting the poll loop.
     */
    @PostConstruct
    public void init() {
        instanceId = ComponentUtil.getSystemHelper().getInstanceId();
        lastEventCheckTime = System.currentTimeMillis();

            throw new FessSystemException("DataService is null. IndexUpdater cannot proceed without a DataService instance.");
        }

        if (logger.isDebugEnabled()) {
            logger.debug("Starting indexUpdater.");
        }

        executeTime = 0;
        documentSize = 0;

        final FessConfig fessConfig = ComponentUtil.getFessConfig();

(Cleanup or Flake)

- DRA device taint eviction: the controller might have reported "1 pod needs to be evicted in 1 namespace. 1 pod evicted since starting the controller." when only a single pod is involved, depending on timing (pod evicted, informer cache not updated yet). It would eventually arrive at the correct "1 pod evicted since starting the controller.", but now it tries harder to avoid the confusing intermediate state by delaying the status update after eviction. ([#137047](https://...

Te contaré más sobre imágenes de contenedores, Docker, Kubernetes, etc. en un capítulo futuro: [FastAPI en Contenedores - Docker](docker.md).

///

## Pasos Previos Antes de Iniciar { #previous-steps-before-starting }

Hay muchos casos en los que quieres realizar algunos pasos **antes de iniciar** tu aplicación.

Por ejemplo, podrías querer ejecutar **migraciones de base de datos**.

Software Foundation; we sometimes make exceptions for this.  Our
decision will be guided by the two goals of preserving the free status
of all derivatives of our free software and of promoting the sharing
and reuse of software generally.

                            NO WARRANTY

  15. BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO
WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW.

   * from the remote peer. Existing streams are not impacted. This is intended to permit an endpoint
   * to gracefully stop accepting new requests without harming previously established streams.
   */
  @Throws(IOException::class)
  fun shutdown(statusCode: ErrorCode) {
    writer.withLock {
      val lastGoodStreamId: Int
      withLock {
        if (isShutdown) {

/// tip | 提示

如果这些关于 **容器**、Docker 或 Kubernetes 的内容还没有多大意义，请不要担心。

我将在以后的章节中向您详细介绍容器镜像、Docker、Kubernetes 等：[容器中的 FastAPI - Docker](docker.md)。

///

## 启动之前的步骤 { #previous-steps-before-starting }

在很多情况下，您希望在**启动**应用程序之前执行一些步骤。

例如，您可能想要运行**数据库迁移**。

但在大多数情况下，您只想执行这些步骤**一次**。

因此，在启动应用程序之前，您将需要一个**单个进程**来执行这些**前面的步骤**。

    } finally {
      this.socketAddress_ = boundSocketAddress
    }

    taskRunner.newQueue().execute(toString(), cancelable = false) {
      try {
        logger.fine("$this starting to accept connections")
        acceptConnections()
      } catch (e: Throwable) {
        logger.log(Level.WARNING, "$this failed unexpectedly", e)
      }

Если вы запускаете **несколько процессов в контейнере**, нужно убедиться, что их суммарное потребление **не превысит доступную память**.

## Предварительные шаги перед запуском и контейнеры { #previous-steps-before-starting-and-containers }

Если вы используете контейнеры (например, Docker, Kubernetes), есть два основных подхода.

### Несколько контейнеров { #multiple-containers }