我在rails服务器中面临nginx网关超时。当我们重新启动rails服务器时，它会工作一段时间，之后会显示504网关超时。我还增加了nginx.config上的超时，但它不工作。请帮助！！
nginx.config

user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

events {
        worker_connections 768;
        # multi_accept on;
}

http {

        ##
        # Basic Settings
        ##
        sendfile on;
        tcp_nopush on;
        tcp_nodelay on;
        keepalive_timeout 65;
        fastcgi_buffers 8 16k;
        fastcgi_buffer_size 32k;
        client_max_body_size 250M;
        types_hash_max_size 2048;
        # server_tokens off;

        # server_names_hash_bucket_size 64;
        # server_name_in_redirect off;

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

        ##
        # SSL Settings
        ##

        ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3; # Dropping SSLv3, ref: 

POODLE
        ssl_prefer_server_ciphers on;

        ##
        # Logging Settings
        ##

        access_log /var/log/nginx/access.log;
        error_log /var/log/nginx/error.log;

        ##
        # Gzip Settings
        ##

        gzip on;

        # gzip_vary on;
        # gzip_proxied any;
        # gzip_comp_level 6;
        # gzip_buffers 16 8k;
        # gzip_http_version 1.1;
        # gzip_types text/plain text/css application/json 

application/javascript text/xml application/xml application/xml+rss 

text/javascript;

        ##
        # Virtual Host Configs
        ##

        include /etc/nginx/conf.d/*.conf;
        include /etc/nginx/sites-enabled/*;
}

# mail {

# # See sample authentication script at:

# # http://wiki.nginx.org/ImapAuthenticateWithApachePhpScript

# 

# # auth_http localhost/auth.php;

# # pop3_capabilities "TOP" "USER";

# # imap_capabilities "IMAP4rev1" "UIDPLUS";

# 

# server {

# listen     localhost:110;

# protocol   pop3;

# proxy      on;

# }

# 

# server {

# listen     localhost:143;

# protocol   imap;

# proxy      on;

# }

# }

站点启用/默认

## 

# You should look at the following URL's in order to grasp a solid understanding

# of Nginx configuration files in order to fully unleash the power of Nginx.

# https://www.nginx.com/resources/wiki/start/

# https://www.nginx.com/resources/wiki/start/topics/tutorials/config_pitfalls/

# https://wiki.debian.org/Nginx/DirectoryStructure

# 

# In most cases, administrators will remove this file from sites-enabled/ and

# leave it as reference inside of sites-available where it will continue to be

# updated by the nginx packaging team.

# 

# This file will automatically load configuration files provided by other

# applications, such as Drupal or Wordpress. These applications will be made

# available underneath a path with that package name, such as /drupal8.

# 

# Please see /usr/share/doc/nginx-doc/examples/ for more detailed examples.

## 

# Default server configuration

# 

# upstream rails_app {

# server app:3000;

# }

upstream app {
  # Path to Puma SOCK file, as defined previously
  server unix:/var/www/bleat_server/tmp/sockets/puma.sock;
  # server 127.0.0.1:3000 fail_timeout=0;
}

server {
        listen 80;

# listen [::]:80 default_server;

        # SSL configuration
        #
        # listen 443 ssl default_server;
        # listen [::]:443 ssl default_server;
        #
        # Note: You should disable gzip for SSL traffic.
         # See: https://bugs.debian.org/773332
        #
        # Read up on ssl_ciphers to ensure a secure configuration.
        # See: https://bugs.debian.org/765782
        #
        # Self signed certs generated by the ssl-cert package
        # Don't use them in a production server!
        #
        # include snippets/snakeoil.conf;

        root /var/www/bleat_server/public;

        # Add index.php to the list if you are using PHP

# index index.html;

        server_name 35.224.174.127;

        location ^~ /assets/ {
            gzip_static on;
            expires max;
            add_header Cache-Control public;
          }

        try_files $uri/index.html $uri @app;

# location / {

# try_files $uri @app;

# }

        location @app {

# proxy_set_header  X-Real-IP  $remote_addr;

            proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header Host $http_host;
            proxy_redirect off;
            proxy_pass http://app;
        }

                                                                                                                                   58,1-8        41%
 client_max_body_size 10M;
        keepalive_timeout 10;

        #location / {
                # First attempt to serve request as file, then
                # as directory, then fall back to displaying a 404.
        #       try_files $uri $uri/ =404;
        #}

# location / {

# proxy_pass http://app;

# proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

# proxy_set_header Host $http_host;

# proxy_redirect off;

# }

        # pass PHP scripts to FastCGI server
        #
        #location ~ \.php$ {
        #       include snippets/fastcgi-php.conf;
        #
        #       # With php-fpm (or other unix sockets):
        #       fastcgi_pass unix:/var/run/php/php7.4-fpm.sock;
        #       # With php-cgi (or other tcp sockets):
        #       fastcgi_pass 127.0.0.1:9000;
        #}

        # deny access to .htaccess files, if Apache's document root
        # concurs with nginx's one
        #
        #location ~ /\.ht {
        #       deny all;
        #}
}

# Virtual Host configuration for example.com

# 

# 

# You can move that to a different file under sites-available/ and symlink that

# to sites-enabled/ to enable it.

# 

# server {

# listen 80;

# listen [::]:80;

# 

# server_name example.com;

# 

# root /var/www/example.com;

# index index.html;

# 

# location / {

# try_files $uri $uri/ =404;

# }

# }

nginx/error.log

2021/07/12 05:15:01 [error] 75827#75827: *1651 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 171.76.253.232, server: admin.bleatfleet.com, request: "POST /users/sign_in HTTP/1.1", upstream: "http://127.0.0.1:3000/users/sign_in", host: "admin.bleatfleet.com", referrer: "http://admin.bleatfleet.com/users/sign_up"

2021/07/12 07:18:17 [crit] 75827#75827: *1696 connect() to unix:/var/www/bleat_server/tmp/sockets/puma.sock failed (2: No such file or directory) while connecting to upstream, client: 192.241.219.165, server: 35.224.174.127, request: "GET / HTTP/1.1", upstream: "http://unix:/var/www/bleat_server/tmp/sockets/puma.sock:/", host: "35.224.174.127"