Apache proxypass - show local file if exist - apache

Question

i use apache proxypass to show content from other server to my base server
i use this code
<VirtualHost *:80>
ServerAdmin webmaster#example.com
DocumentRoot /var/www/html/2
ServerName 2.example.com
ProxyPass /tv http://t1.example.com/tv/
ProxyPassReverse /tv http://t1.example.com/tv/
ErrorLog logs/errorlive_log
CustomLog logs/access_live common
</VirtualHost>
so is there a way first to check if file exist on 2.example.com (/var/www/html/2) if file exist show from this server and if file dont exist then request and server from t1.example.com/tv/
-and i have second question:
if server2 serve a video which is located in server1 and on server 2 are watching 10 users (10mbps) , so from which server will be taken 10mbps from server 2 or server 1 or both servers will have 10mbps load

Answer 1

In apache doc,you can see Ordering ProxyPass and RewriteRule Directives
RewriteRule directives are evaluated before ProxyPass ones.
So, you can add a rewrite rule which test if file exist
<VirtualHost *:80>
ServerAdmin webmaster#example.com
DocumentRoot /var/www/html/2
ServerName 2.example.com
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} -f
RewriteRule .* - [L]
ProxyPass /tv http://t1.example.com/tv/
ProxyPassReverse /tv http://t1.example.com/tv/
ErrorLog logs/errorlive_log
CustomLog logs/access_live common
</VirtualHost>
RewiteCond test if %{REQUEST_FILENAME} is a regular file and then rewriteRule rewrites to the file. It can be a html, image, php file, etc ...
Now, you can adapt to your need.
EDIT
For second question, I forgot to answer. Sorry, my bad.
According to Apache mod_proxy documentation :
"A reverse proxy (or gateway), by contrast, appears to the client just like an ordinary web server. No special configuration on the client is necessary. The client makes ordinary requests for content in the namespace of the reverse proxy. The reverse proxy then decides where to send those requests and returns the content as if it were itself the origin."
So, both server are loaded.