请教一个 nginx 请求方面的问题

我用 gunicorn+django 部署了一个项目。前端页面调接口 nginx 提示 error:

[alert] 8#8: *12811 zero size buf in writer t:1 r:1 f:0 000056152536F2F0 000056152536F2F0-000056152536F2F0 0000000000000000 0-0 while sending to client

nginx 配置如下：

   ssl_certificate   conf.d/letsencrypt/3481255__bolineyecare.com.pem;
    ssl_certificate_key  conf.d/letsencrypt/3481255__bolineyecare.com.key;
    ssl_session_timeout 5m;
    ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE:ECDH:AES:HIGH:!NULL:!aNULL:!MD5:!ADH:!RC4;
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_prefer_server_ciphers on;
    charset utf-8;
    expires +0d;
    add_header Pragma "no-cache";

    root  /usr/share/nginx/html/collets_web/dist;
    client_max_body_size    2000m;
    client_body_buffer_size 2000m;
    proxy_read_timeout  20m;

    gzip on;
    gzip_min_length 4k;
    gzip_buffers 4 16k;
    gzip_comp_level 6;
    gzip_types text/plain application/x-javascript text/css application/xml application/javascript application/json;
    gzip_vary on;
    gzip_http_version 1.1;

   # rewrite ^/$ /admin/ last;
    location /api/purchasing/ {
       proxy_pass    http://127.0.0.1:9527/api/purchasing/;
        proxy_redirect    off;
        proxy_set_header    Host    $host;
        proxy_set_header    X-Real-IP    $remote_addr;
        proxy_set_header    X-Forwarded-For    $proxy_add_x_forwarded_for;
        add_header    Cache-Control no-store;
        client_max_body_size    2000m;
    }

这两天 baidu 、google 都还没有找到问题。有一种说法是数据的问题。