biggerBufMin = 32 << 10

	// This is the maximum size of bigger buffers.
	biggerBufMax = maxBufferSize

	// If there is a queue, merge up to this many messages.
	maxMergeMessages = 50

	// clientPingInterval will ping the remote handler every 15 seconds.
	// Clients disconnect when we exceed 2 intervals.
	clientPingInterval = 15 * time.Second

	// Deadline for single (non-streaming) requests to complete.

            for (ChannelInfo channel : channelGroup.getChannels()) {
                try {
                    // Simplified health check - in real implementation would ping the channel
                    boolean isHealthy = checkChannelHealth(channel);
                    channel.setHealthy(isHealthy);

                    if (!isHealthy) {

		if peer == nil {
			continue
		}
		peer.Listen(ctx, mergeCh, values)
	}

	var (
		emptyEventTicker <-chan time.Time
		keepAliveTicker  <-chan time.Time
	)

	if p := values.Get("ping"); p != "" {
		pingInterval, err := strconv.Atoi(p)
		if err != nil {
			writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidQueryParams), r.URL)
			return
		}
		if pingInterval < 1 {

pkg database/sql/driver, type NamedValue struct, Ordinal int
pkg database/sql/driver, type NamedValue struct, Value Value
pkg database/sql/driver, type Pinger interface { Ping }
pkg database/sql/driver, type Pinger interface, Ping(context.Context) error
pkg database/sql/driver, type QueryerContext interface { QueryContext }

    when pooled connections are evicted).

    If you have a configured ping interval, you should confirm that it is long
    enough for a roundtrip from client to server. If your ping interval is too
    short, slow connections may be misinterpreted as failed connections. A ping
    interval of 30 seconds is reasonable for most use cases.

{* ../../docs_src/server_sent_events/tutorial005_py310.py hl[14] *}

## 기술 세부사항 { #technical-details }

FastAPI는 일부 SSE 모범 사례를 기본으로 구현합니다.

- 메시지가 없을 때는 15초마다 **"keep alive" `ping` 주석**을 보내 일부 프록시가 연결을 종료하지 않도록 합니다. [HTML 사양: Server-Sent Events](https://html.spec.whatwg.org/multipage/server-sent-events.html#authoring-notes)에서 권장합니다.
- 스트림이 **캐시되지 않도록** `Cache-Control: no-cache` 헤더를 설정합니다.

## Détails techniques { #technical-details }

FastAPI met en œuvre certaines bonnes pratiques SSE prêtes à l’emploi.

{* ../../docs_src/server_sent_events/tutorial005_py310.py hl[14] *}

## 技术细节 { #technical-details }

FastAPI 开箱即用地实现了一些 SSE 的最佳实践。

- 当 15 秒内没有任何消息时，发送一个**保活 `ping` 注释**，以防某些代理关闭连接，正如 [HTML 规范：Server-Sent Events](https://html.spec.whatwg.org/multipage/server-sent-events.html#authoring-notes) 中建议的那样。
- 设置 `Cache-Control: no-cache` 响应头，**防止缓存**流。

      errorCode: ErrorCode,
    ) {
      check(type == -1)
      this.type = Http2.TYPE_RST_STREAM
      this.streamId = streamId
      this.errorCode = errorCode
    }

    override fun ping(
      ack: Boolean,
      payload1: Int,
      payload2: Int,
    ) {
      check(type == -1)
      type = Http2.TYPE_PING
      this.ack = ack
      this.payload1 = payload1

	}
	if n != len(p) {
		err = io.ErrShortWrite
		b.closeWithErr(err)
	}
	return n, err
}

func (b *streamingBitrotWriter) Close() error {
	// Close the underlying writer.
	// This will also flush the ring buffer if used.
	err := b.iow.Close()

	// Wait for all data to be written before returning else it causes race conditions.
	// Race condition is because of io.PipeWriter implementation. i.e consider the following