location /download/ {
    alias /var/www/downloads;
    proxy_pass http://localhost:8080;
    proxy_buffering off;           # ?? 關鍵！禁用緩沖，啟用流式傳輸
    proxy_cache off;               # ?? 禁用緩存
    proxy_read_timeout 300s;       # ?? 延長后端讀取超時
    proxy_send_timeout 300s;       # ?? 延長后端發(fā)送超時
    send_timeout 600s;             # ?? 延長向客戶端發(fā)送響應的超時
    client_max_body_size 10G;      # ?? 允許上傳大文件
    keepalive_timeout 300s;        # ?? 保持長連接
}

location /download/ {
    alias /var/www/downloads;
    proxy_pass http://localhost:8080;
    proxy_buffering on;
    proxy_buffer_size 128k;        # ?? 單個緩沖區(qū)大小
    proxy_buffers 8 128k;          # ?? 緩沖區(qū)數(shù)量 × 大小
    proxy_busy_buffers_size 256k;  # ?? 忙碌時允許使用的緩沖區(qū)上限
    proxy_temp_file_write_size 256k;
    proxy_temp_path /tmp/nginx_proxy_temp;

    proxy_read_timeout 600s;
    proxy_send_timeout 600s;
    send_timeout 1200s;
    client_max_body_size 20G;
    keepalive_timeout 300s;
}

upstream java_backend {
    server localhost:8080;
    keepalive 32;                  # ?? 保持 32 個空閑連接
    keepalive_timeout 300s;        # ?? 連接空閑超時
    keepalive_requests 1000;       # ?? 每個連接最多處理 1000 個請求
}

location /download/ {
    proxy_pass http://java_backend;
    proxy_http_version 1.1;        # ?? 必須啟用 HTTP/1.1 才能使用 keepalive
    proxy_set_header Connection "";
}

client_header_buffer_size 16k;
large_client_header_buffers 4 16k;

net.core.somaxconn = 65535
net.ipv4.tcp_max_syn_backlog = 65535
net.ipv4.tcp_fin_timeout = 30
net.ipv4.tcp_keepalive_time = 120
net.ipv4.tcp_keepalive_intvl = 30
net.ipv4.tcp_keepalive_probes = 3

sudo sysctl -p

gzip on;
gzip_vary on;
gzip_min_length 1024;
gzip_types text/plain application/json application/xml text/css application/javascript;

package com.example.downloads;
import org.springframework.core.io.InputStreamResource;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
@RestController
public class FileDownloadController {
    private static final String DOWNLOAD_DIR = "/var/www/downloads/";
    @GetMapping("/download/{filename}")
    public ResponseEntity<Resource> downloadFile(@PathVariable String filename) throws IOException {
        Path filePath = Paths.get(DOWNLOAD_DIR, filename);
        File file = filePath.toFile();
        if (!file.exists() || !file.isFile()) {
            return ResponseEntity.notFound().build();
        }
        // ?? 關鍵：使用 InputStreamResource 實現(xiàn)流式傳輸
        InputStreamResource resource = new InputStreamResource(new FileInputStream(file));
        // ?? 設置響應頭：告訴客戶端這是一個大文件下載
        HttpHeaders headers = new HttpHeaders();
        headers.add(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + filename + "\"");
        headers.add(HttpHeaders.CONTENT_LENGTH, String.valueOf(file.length()));
        headers.add(HttpHeaders.ACCEPT_RANGES, "bytes"); // ?? 支持斷點續(xù)傳
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        // ?? 使用 ResponseEntity 返回流，不加載整個文件到內(nèi)存
        return ResponseEntity.ok()
                .headers(headers)
                .contentLength(file.length())
                .body(resource);
    }
}

@GetMapping("/download/{filename}")
public ResponseEntity<Resource> downloadFileWithRange(@PathVariable String filename, 
                                                      HttpServletRequest request) throws IOException {
    Path filePath = Paths.get(DOWNLOAD_DIR, filename);
    File file = filePath.toFile();
    if (!file.exists() || !file.isFile()) {
        return ResponseEntity.notFound().build();
    }
    long fileSize = file.length();
    long start = 0;
    long end = fileSize - 1;
    // ?? 解析 Range 請求頭
    String rangeHeader = request.getHeader("Range");
    if (rangeHeader != null && rangeHeader.startsWith("bytes=")) {
        String[] range = rangeHeader.substring(6).split("-");
        start = Long.parseLong(range[0]);
        if (range.length > 1 && !range[1].isEmpty()) {
            end = Long.parseLong(range[1]);
        }
    }
    long contentLength = end - start + 1;
    InputStreamResource resource = new InputStreamResource(new FileInputStream(file)) {
        @Override
        public InputStream getInputStream() throws IOException {
            FileInputStream fis = new FileInputStream(file);
            fis.skip(start); // ?? 跳過前面字節(jié)
            return fis;
        }
    };
    HttpHeaders headers = new HttpHeaders();
    headers.add(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + filename + "\"");
    headers.add(HttpHeaders.CONTENT_RANGE, "bytes " + start + "-" + end + "/" + fileSize);
    headers.add(HttpHeaders.ACCEPT_RANGES, "bytes");
    headers.add(HttpHeaders.CONTENT_LENGTH, String.valueOf(contentLength));
    headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
    // ?? 根據(jù)是否是部分請求返回 206 或 200
    if (rangeHeader != null) {
        return ResponseEntity.status(206) // Partial Content
                .headers(headers)
                .body(resource);
    } else {
        return ResponseEntity.ok()
                .headers(headers)
                .contentLength(fileSize)
                .body(resource);
    }
}

curl -v -o /dev/null http://localhost:8080/download/large-file.zip

< Content-Length: 2147483648
< Content-Disposition: attachment; filename="large-file.zip"
< Accept-Ranges: bytes

Files.copy(Paths.get("file.zip"), response.getOutputStream()); // ? 錯誤！

tail -f /var/log/nginx/error.log | grep -i "upstream timed out\|client intended to send too large body"

docker run -d -p 9113:9113 --name nginx-exporter \
  -e NGINX_PLUS=false \
  -e NGINX_SCRAPE_URI=http://localhost:80/nginx_status \
  nginx/nginx-prometheus-exporter:0.10.0

location /nginx_status {
    stub_status on;
    access_log off;
    allow 127.0.0.1;
    deny all;
}

- alert: NginxProxyTimeoutHigh
  expr: rate(nginx_http_requests_total{status="504"}[5m]) > 0.1
  for: 10m
  labels:
    severity: critical
  annotations:
    summary: "Nginx 504 超時率超過 10% / 分鐘"
    description: "請檢查 proxy_read_timeout 和后端響應速度"

long startTime = System.currentTimeMillis();
try {
    // ... 下載邏輯
} finally {
    long duration = System.currentTimeMillis() - startTime;
    log.info("Download completed: {} bytes in {} ms", fileSize, duration);
}

import io.minio.MinioClient;
import io.minio.PutObjectArgs;
MinioClient minioClient = MinioClient.builder()
    .endpoint("http://localhost:9000")
    .credentials("minioadmin", "minioadmin")
    .build();
minioClient.putObject(
    PutObjectArgs.builder()
        .bucket("downloads")
        .object("large-file.zip")
        .stream(inputStream, fileSize, -1)
        .contentType("application/octet-stream")
        .build()
);

location /download/ {
    internal;
    alias /var/www/downloads;
}
location /files/ {
    set $target "";
    if (-f /var/www/downloads/$request_uri) {
        set $target http://minio-server:9000/downloads/$request_uri;
    }
    if ($http_user_agent ~* "(curl|wget|IDM)") {
        return 302 $target;
    }
    # 瀏覽器直接訪問，返回 Nginx 代理（用于權限校驗）
    proxy_pass http://java-backend;
}

# /etc/nginx/sites-available/large-file-download

server {
    listen 80;
    server_name files.example.com;

    # 大文件下載目錄
    location /download/ {
        alias /var/www/downloads;
        proxy_pass http://localhost:8080;
        proxy_buffering off;
        proxy_cache off;
        proxy_read_timeout 900s;
        proxy_send_timeout 900s;
        send_timeout 1800s;
        client_max_body_size 50G;
        keepalive_timeout 300s;
        proxy_http_version 1.1;
        proxy_set_header Connection "";

        # 安全頭
        add_header X-Content-Type-Options nosniff;
        add_header X-Frame-Options DENY;
        add_header X-XSS-Protection "1; mode=block";
    }

    # Nginx 狀態(tài)頁（僅內(nèi)網(wǎng)訪問）
    location /nginx_status {
        stub_status on;
        access_log off;
        allow 192.168.0.0/16;
        deny all;
    }

    # 錯誤頁面
    error_page 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/html;
    }
}

# 全局配置
http {
    client_header_buffer_size 16k;
    large_client_header_buffers 4 16k;
    tcp_nodelay on;
    tcp_nopush on;
    sendfile on;
    keepalive_timeout 300s;
    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_types text/plain application/json application/xml text/css application/javascript;
}