Upload big Size File SSL_write() failed (32: Broken pipe) error

[Koichi]

Because the error message "Maximum number of external links per post exceeded"
I Change websiete to websiete.
[ec2-user@ip-xxx-xxx-xxx-xxx ~]$ cat /etc/os-release

NAME="Amazon Linux"
VERSION="2"
ID="amzn"
ID_LIKE="centos rhel fedora"
VERSION_ID="2"
PRETTY_NAME="Amazon Linux 2"
ANSI_COLOR="0;33"
CPE_NAME="cpe:2.3:o:amazon:amazon_linux:2"
HOME_URL="websiete://amazonlinux.com/"

I have problems with nginx.
I upload a big-size file of more than 800MB.
And I got an error:

2023/02/07 20:53:54 [error] 27686#27686: *15265 SSL_write() failed (32: Broken pipe) while sending request to upstream, client: xxx.xxx.xxx.xxx, server: mysite.xyz, request: "POST /management-upload HTTP/1.1", upstream: "websiete://127.0.0.1:9993/management-upload", host: "mysite.xyz", referrer: "websiete://mysite.xyz/console/index.html"
2023/02/07 20:53:54 [debug] 27686#27686: *15265 chain writer out: FFFFFFFFFFFFFFFF
2023/02/07 20:53:54 [debug] 27686#27686: *15265 http next upstream, 2
2023/02/07 20:53:54 [debug] 27686#27686: *15265 free rr peer 1 4
2023/02/07 20:53:54 [debug] 27686#27686: *15265 finalize http upstream request: 502
2023/02/07 20:53:54 [debug] 27686#27686: *15265 finalize http proxy request
2023/02/07 20:53:54 [debug] 27686#27686: *15265 SSL_shutdown: 1
2023/02/07 20:53:54 [debug] 27686#27686: *15265 close http upstream connection: 15
2023/02/07 20:53:54 [debug] 27686#27686: *15265 free: 0000AAAAF61E0130
2023/02/07 20:53:54 [debug] 27686#27686: *15265 free: 0000AAAAF56026A0
2023/02/07 20:53:54 [debug] 27686#27686: *15265 free: 0000AAAAF55E8AF0
2023/02/07 20:53:54 [debug] 27686#27686: *15265 free: 0000AAAAF5612160, unused: 0
2023/02/07 20:53:54 [debug] 27686#27686: *15265 event timer del: 15: 812062421
2023/02/07 20:53:54 [debug] 27686#27686: *15265 reusable connection: 0
2023/02/07 20:53:54 [debug] 27686#27686: *15265 http finalize request: 502, "/management-upload?" a:1, c:1
2023/02/07 20:53:54 [debug] 27686#27686: *15265 http special response: 502, "/management-upload?"
2023/02/07 20:53:54 [debug] 27686#27686: *15265 HTTP/1.1 502 Bad Gateway
Server: nginx/1.22.0
Date: Tue, 07 Feb 2023 11:53:54 GMT
Content-Type: text/html
Content-Length: 559
Connection: keep-alive

cat nginx.conf

# For more information on configuration, see:
#   * Official English Documentation: http://nginx.org/en/docs/
#   * Official Russian Documentation: http://nginx.org/ru/docs/

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log debug;
pid /run/nginx.pid;

# Load dynamic modules. See /usr/share/doc/nginx/README.dynamic.
include /usr/share/nginx/modules/*.conf;

events {
    worker_connections 1024;
}

http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile            on;
    tcp_nopush          on;
    tcp_nodelay         on;
    keepalive_timeout   120;
    types_hash_max_size 4096;

    include             /etc/nginx/mime.types;
    default_type        application/octet-stream;

    # Load modular configuration files from the /etc/nginx/conf.d directory.
    # See http://nginx.org/en/docs/ngx_core_module.html#include
    # for more information.
    include /etc/nginx/conf.d/*.conf;


upstream backend {
    server localhost:8080;
}

#upstream mgtcon {
#    server localhost:9990;
#}

upstream mgtcon{
    server localhost:9993;
}
server {
    listen         80;
    server_name    mysite.xyz;
    add_header     Strict-Transport-Security "max-age=31536000; includeSubdomains";

    location ^~ /.well-known {
        root /usr/share/nginx/html;
    }

    location / {
        return 301 websiete://$host$request_uri;
    }
}
server {
    listen         443 ssl;
    server_name    mysite.xyz;
    client_max_body_size 1000m;
    ssl_session_timeout 1d;
    ssl_session_cache shared:SSL:10m;
    ssl_session_tickets off;
    ssl_buffer_size 3000k;

    ssl_dhparam /etc/nginx/ssl/dhparam.pem;

    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384;
    ssl_prefer_server_ciphers on;
    ssl_certificate /etc/letsencrypt/live/mysite.xyz/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/mysite.xyz/privkey.pem; # managed by Certbot

#        root         /usr/share/nginx/html;

    location / {
        include conf.d/proxy_headers.conf;
        proxy_pass http://backend/;
    }


    location /management {
        include conf.d/proxy_headers.conf;
        proxy_pass websiete://mgtcon/management;
    }
    location /console {
        include conf.d/proxy_headers.conf;
        proxy_pass websiete://mgtcon/console;
    }
    location /logout {
        include conf.d/proxy_headers.conf;
        proxy_pass websiete://mgtcon/logout;
    }
    location /error {
        include conf.d/proxy_headers.conf;
        proxy_pass websiete://mgtcon;
    }

  }
}

cat conf.d/proxy_headers.conf

proxy_set_header Host $host;
proxy_set_header X-Forwarded-Proto $scheme;

proxy_buffering on;
proxy_busy_buffers_size 4000k;
proxy_buffer_size 4000k;
proxy_buffers 8 1000k;
#proxy_set_header X-Forwarded-Proto https;
#proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
add_header Front-End-Https on;
add_header Cache-Control no-cache;


client_body_buffer_size 20971520k;

#proxy_request_buffering on;
#add_header Front-End-websiete on;