daemon["Gradle daemon"]
        gradle --> daemon
        gradlew --> daemon
        tapi --> daemon
        
        worker["Worker process"]
        daemon --> worker

        worker2["Worker process"]
        daemon --> worker2

        worker3["Worker process"]
        daemon --> worker3
    
```

These are all Java processes. Each process has a corresponding "runtime".

Insbesondere wenn die Anwendung auf **Kubernetes** läuft, werden Sie wahrscheinlich **keine** Worker verwenden wollen, und stattdessen **einen einzelnen Uvicorn-Prozess pro Container** ausführen wollen, aber ich werde Ihnen später in diesem Kapitel mehr darüber erzählen.

///

## Mehrere Worker { #multiple-workers }

Sie können mehrere Worker mit der `--workers`-Befehlszeilenoption starten:

//// tab | `fastapi`

En particular, cuando corras en **Kubernetes** probablemente **no** querrás usar workers y en cambio correr **un solo proceso de Uvicorn por contenedor**, pero te contaré sobre eso más adelante en ese capítulo.

///

## Múltiples Workers { #multiple-workers }

Puedes iniciar múltiples workers con la opción de línea de comando `--workers`:

//// tab | `fastapi`

Si usas el comando `fastapi`:

<div class="termy">

In particular, when running on **Kubernetes** you will probably **not** want to use workers and instead run **a single Uvicorn process per container**, but I'll tell you about it later in that chapter.

///

## Multiple Workers { #multiple-workers }

You can start multiple workers with the `--workers` command line option:

//// tab | `fastapi`

If you use the `fastapi` command:

<div class="termy">

```

</div>

////

这里唯一的新选项是 `--workers` 告诉 Uvicorn 启动 4 个工作进程。

您还可以看到它显示了每个进程的 **PID**，父进程（这是**进程管理器**）的 PID 为`27365`，每个工作进程的 PID 为：`27368`、`27369`， `27370`和`27367`。

## 部署概念

在这里，您学习了如何使用多个**工作进程（workers）**来让应用程序的执行**并行化**，充分利用 CPU 的**多核性能**，并能够处理**更多的请求**。

从上面的部署概念列表来看，使用worker主要有助于**复制**部分，并对**重新启动**有一点帮助，但您仍然需要照顾其他部分：

* **安全 - HTTPS**
* **启动时运行**

///

## Несколько воркеров { #multiple-workers }

Можно запустить несколько воркеров с помощью опции командной строки `--workers`:

//// tab | `fastapi`

Если вы используете команду `fastapi`:

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> run --workers 4 <u style="text-decoration-style:solid">main.py</u>

		// If the channel reaches above half capacity
		// we spawn more workers. The workers spawned
		// from this main worker routine will exit
		// once the channel drops below half capacity
		// and when it's been at least 30 seconds since
		// we launched a new worker.
		if mainWorker && len(h.logCh) > cap(h.logCh)/2 {
			nWorkers := h.workers.Load()
			if nWorkers < h.maxWorkers {
				if time.Since(h.lastStarted).Milliseconds() > 10 {

COPY ./app /code/app

# (1)!
CMD ["fastapi", "run", "app/main.py", "--port", "80", "--workers", "4"]
```

1. Hier verwenden wir die `--workers` Befehlszeilenoption, um die Anzahl der Worker auf 4 festzulegen.

Hier sind einige Beispiele, wann das sinnvoll sein könnte:

#### Eine einfache Anwendung { #a-simple-app }

	if (checkOld > 0 && len(p.workers) != checkOld) || n == len(p.workers) || n < 1 {
		// Either already satisfied or worker count changed while we waited for the lock.
		return
	}
	for len(p.workers) < n {
		input := make(chan ReplicationWorkerOperation, 10000)
		p.workers = append(p.workers, input)

		go p.AddWorker(input, &p.activeWorkers)
	}
	for len(p.workers) > n {
		worker := p.workers[len(p.workers)-1]

		workers = workers[:len(workers)-1]
		worker <- expiryOp(nil)
		es.stats.workers.Add(-1)
	}
	// Atomically replace workers.
	es.workers.Store(&workers)
}

// Worker handles 4 types of expiration tasks.
// 1. Expiry of objects, includes regular and transitioned objects
// 2. Expiry of noncurrent versions due to NewerNoncurrentVersions