///

And when working with containers, the same system you use to start and manage them would already have internal tools to transmit the **network communication** (e.g. HTTP requests) from that **load balancer** (that could also be a **TLS Termination Proxy**) to the container(s) with your app.

- 🔒 Secure password hashing by default.
- 🔑 JWT (JSON Web Token) authentication.
- 📫 Email based password recovery.
- ✅ Tests with [Pytest](https://pytest.org).
- 📞 [Traefik](https://traefik.io) as a reverse proxy / load balancer.
- 🚢 Deployment instructions using Docker Compose, including how to set up a frontend Traefik proxy to handle automatic HTTPS certificates.

* type hints: аннотации типов
* type annotations: аннотации типов
* context manager: менеджер контекста
* code base: кодовая база
* instantiate: создать экземпляр (avoid "инстанцировать")
* load balancer: балансировщик нагрузки
* load balance: балансировка нагрузки
* worker process: воркер-процесс (or `процесс воркера`)
* worker: воркер

            Optional comment line(s).

            Comment lines start with `:` in the SSE wire format and are ignored by
            `EventSource` clients. Useful for keep-alive pings to prevent
            proxy/load-balancer timeouts.
            """
        ),
    ] = None

    @model_validator(mode="after")
    def _check_data_exclusive(self) -> "ServerSentEvent":
        if self.data is not None and self.raw_data is not None:

 * Sessions are stored in memory with automatic expiration.
 *
 * <p><b>Note:</b> Sessions are stored in a local in-memory ConcurrentHashMap.
 * In multi-instance deployments (e.g., behind a load balancer), sessions are
 * not shared between instances. Use sticky sessions or an external session
 * store if session affinity across instances is required.</p>
 *
 * @author FessProject
 */
public class ChatSessionManager {

在這些情況下，你大概會想要如[上面所述](#dockerfile)從零開始建置一個 Docker 映像，安裝你的相依，並且只執行「單一 Uvicorn 行程」，而不是使用多個 Uvicorn workers。

### 負載平衡器 { #load-balancer }

使用容器時，通常會有某個元件在「主埠口」上監聽。它也可能是另一個同時做為「TLS 終止代理」的容器來處理「HTTPS」，或類似的工具。

由於這個元件會承接請求的「負載」，並將其分配給 workers，使其（希望）「平衡」，因此也常被稱為「負載平衡器（Load Balancer）」。

/// tip | 提示

用於 HTTPS 的同一個「TLS 終止代理」元件通常也會是「負載平衡器」。

///

그런 경우에는 [위에서 설명한 대로](#dockerfile) 의존성을 설치하고, 여러 Uvicorn 워커를 사용하는 대신 **단일 Uvicorn 프로세스**를 실행하는 **처음부터 만든 Docker 이미지**를 사용하는 것이 좋을 것입니다.

### 로드 밸런서 { #load-balancer }

컨테이너를 사용할 때는 보통 **메인 포트에서 대기(listening)하는** 컴포넌트가 있습니다. **HTTPS**를 처리하기 위한 **TLS 종료 프록시** 역할을 하는 다른 컨테이너일 수도 있고, 유사한 도구일 수도 있습니다.

이 컴포넌트가 요청의 **부하(load)**를 받아 워커들에 (가능하면) **균형 있게** 분산한다면, 보통 **로드 밸런서**라고 부릅니다.

### 프록시 전달 헤더가 동작하는 방식 { #how-proxy-forwarded-headers-work }

다음은 **프록시**가 클라이언트와 **애플리케이션 서버** 사이에서 전달 헤더를 추가하는 과정을 시각적으로 나타낸 것입니다:

```mermaid
sequenceDiagram
    participant Client
    participant Proxy as Proxy/Load Balancer
    participant Server as FastAPI Server

    Client->>Proxy: HTTPS Request<br/>Host: mysuperapp.com<br/>Path: /items

    Note over Proxy: Proxy adds forwarded headers

Here's a visual representation of how the **proxy** adds forwarded headers between the client and the **application server**:

```mermaid
sequenceDiagram
    participant Client
    participant Proxy as Proxy/Load Balancer
    participant Server as FastAPI Server

    Client->>Proxy: HTTPS Request<br/>Host: mysuperapp.com<br/>Path: /items

    Note over Proxy: Proxy adds forwarded headers

 *           // Services have been initialized and are healthy, start accepting requests...
 *         }
 *         public void failure(Service service) {
 *           // Something failed, at this point we could log it, notify a load balancer, or take
 *           // some other action.  For now we will just exit.
 *           System.exit(1);
 *         }
 *       },
 *       MoreExecutors.directExecutor());
 *