Why might the nginx proxy not work?

Question

Nginx

Good afternoon! We had an owncloud corporate cloud, and it fell in one day! I set a senior task to make nginx on the proxy server and apache on the backend. Found an article , did everything, set it up, everything worked. The authorities were impatient to upload 10G files to the cloud, then apache began to eat resources. There is a task to transfer the backend to nginx made from here . I translated it, but now the problem is that the frontend completely redirects to one of the backend servers, but is not a proxy server. All this miracle works on centos 7, nginx 1.6.3, php-fpm - PHP 5.4.16 (fpm-fcgi). Tell me what I am stupid or what I do not understand. Thank you all in advance.
nginx.conf config on the proxy server:

server {
        listen       80;
        listen       443 ssl;
        server_name  10.0.0.61;
        ssl_certificate     /etc/nginx/certs/owncloud.crt;     
        ssl_certificate_key /etc/nginx/certs/owncloud.key;
        include /etc/nginx/default.d/*.conf;
        if ( $scheme = "http" ) {
        rewrite ^/(.*)$ https://$host/$1 permanent;
}

location / {
        root /usr/share/nginx/html/;
        index index.html;       
}

virtual host config /etc/nginx/conf.d/owncloud.server.com.conf

upstream myCloud {
    ip_hash;
    server 10.0.0.63:80
    server 10.0.0.64:80;
}
server {
    listen       443 ssl;		
    server_name  10.0.0.61;
    ssl_certificate     /etc/nginx/certs/owncloud.crt;    
    ssl_certificate_key /etc/nginx/certs/owncloud.key;
    client_max_body_size 10G; # максимальный файл для загрузки
    location / {
    proxy_pass   http://myCloud;
    proxy_set_header   Host   $host;
    proxy_set_header   X-Real-IP  $remote_addr;
    proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
       }
 }

nginx.conf config of one of the backends

server {
        listen 80;
        server_name 10.0.0.64;  
      include /etc/nginx/default.d/*.conf;
        location / {
        root /usr/share/nginx/html/;
        index index.html index.htm;
       }
        error_page 404 /404.html;
            location = /40x.html {
        }
        error_page 500 502 503 504 /50x.html;
           location = /50x.html {
        }
    }

virtual host config /etc/nginx/conf.d/owncloud.conf

upstream php-handler {
    server 127.0.0.1:9000;
}
server {
        listen 80;
        server_name 10.0.0.64;
       client_max_body_size 10G; # set max uIpload size
        fastcgi_buffers 64 4K;
         location = / {
        root /usr/share/nginx/html/owncloud/;
        index index.php;
        rewrite ^/caldav(.*)$ /remote.php/caldav$1 redirect;
        rewrite ^/carddav(.*)$ /remote.php/carddav$1 redirect;
        rewrite ^/webdav(.*)$ /remote.php/webdav$1 redirect;
        error_page 403 /core/templates/403.php;
        error_page 404 /core/templates/404.php;
}
        location = /robots.txt {
            allow all;
            log_not_found off;
            access_log off;
        }
        location ~ ^/(data|config|\.ht|db_structure\.xml|README) {
                deny all;
        }

        location / {
                  rewrite ^/.well-known/host-meta /public.php?service=host-meta last;
                rewrite ^/.well-known/host-meta.json /public.php?service=host-meta-json last;
                rewrite ^/.well-known/carddav /remote.php/carddav/ redirect;
                rewrite ^/.well-known/caldav /remote.php/caldav/ redirect;
                rewrite ^(/core/doc/[^\/]+/)$ $1/index.html;
                try_files $uri $uri/ index.php;
        }
 location ~ ^(.+?\.php)(/.*)?$ {
                try_files $1 = 404;
                include fastcgi_params;
                fastcgi_param SCRIPT_FILENAME $document_root$1;
                fastcgi_param PATH_INFO $2;
                fastcgi_pass php-handler;
        }
       location ~* ^.+\.(jpg|jpeg|gif|bmp|ico|png|css|js|swf)$ {
               expires 30d;
               access_log off;
       }

}

Answer 1

when owcloud + rouncube was integrated due to incorrect proxy settings, the senior said to remove the proxy, leave one server with nginx and php-fpm. Thank you all for your help

Answer 2

Open the phrase

Translated, but now the problem is that the frontend completely redirects to one of the backend servers, but is not a proxy server
You have proxying for all uris in your config:

location / {
proxy_pass http://myCloud;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}

That is, all requests are proxied to the myCloud upstream. The
blanching inside the upstream goes according to ip_hash, that is, one client will always go to one server.

upstream myCloud {
ip_hash;
server 10.0.0.63:80
server 10.0.0.64:80;
}

If this is not the expected behavior, change it.

Answer 3

it seems to me that instead of a redirect,
rewrite ^/(.*)$ https://$host/$1 permanent;
do
return 301 https://$server_name$request_uri;
since it is quite possible that after the first request to the back $host will change