Update SCALING.md

rtfm/SCALING.md

@@ -1,6 +1,6 @@
 # How to scale PictShare
 
-If your library is huge then you might want to think about scaling your instances. Pictshare (v2+) was rebuilt with scaling in mind but instead of built-in scaling features we use a smarter system
+If your library is huge then you might want to think about scaling your instances. Pictshare (v2+) was rebuilt with scaling in mind but instead of built-in scaling features we rely on OS level solutions.
 
 # The "ALT_FOLDER" setting
 You can set the config var ```ALT_FOLDER``` to point to a directory on the same server where pictshare will look for content and put new uploads.
@@ -9,4 +9,46 @@ This allows you to have a shared or even a mounted ftp/nfs folder that will act
 
 The main site https://pictshare.net uses this technique to scale across many servers in multiple countries.
 
-Using this method you can have multiple servers for the same domain (with a reverse proxy)
+Using this method you can have multiple servers for the same domain (with a reverse proxy)
+
+# Fast, read only instances
+PictShare needs strong hardware for video conversion but using smart Nginx configurations you can host an instance on a weak but fast server and relay all uploads to another server with stronger hardware running PictShare
+
+**Example Nginx config for a small VPS that relay all uploads to a faster but private server**
+
+```
+server {
+        listen 80;
+        server_name your.awesome.domain.name;
+
+        client_max_body_size 50M; # Set the max file upload size. This needs to be equal or larger than the size you specified in your php.ini
+
+        root /var/www/pictshare; # or where ever you put it
+        index index.php;
+
+    location / {
+        try_files $uri $uri/ /index.php?url=$request_uri;
+    }
+    
+    # Magic begins here. Since all uploads have to be made via some script in the /api/ folder we can just redirect
+    # these requests to another server that doesn't need to be public facing
+    location ^~ /api/ {
+        proxy_pass          http://10.12.0.3/; #set to the hostname or ip or url of the powerful server
+        include /etc/nginx/proxy_params;
+    }
+
+    location ~ \.php {
+        fastcgi_pass unix:/var/run/php/php7.3-fpm.sock; #may be slightly different depending on your php version
+        fastcgi_index index.php;
+        include fastcgi_params;
+        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
+        fastcgi_param PATH_INFO $fastcgi_script_name;
+    }
+
+    location ~ /(data|tmp|bin|content-controllers|inc|interfaces|storage-controllers|templates|tools) {
+       deny all;
+       return 404;
+    }
+
+}
+```