What happens when all the servers are busy

Hello,

I want to know il it is possible to configure Nginx to keep in memory a incoming request when all server are busy.
When a server become available, Nginx gives it the pending request.

When I say server, I am telling about socket declared like this in Nginx configuration :

upstream fastcgi_authorizer_servers {
server unix:/var/tmp/nginx/fastcgi-authorizer-1.socket max_conns=1;
server unix:/var/tmp/nginx/fastcgi-authorizer-2.socket max_conns=1;
server unix:/var/tmp/nginx/fastcgi-authorizer-3.socket max_conns=1;
server unix:/var/tmp/nginx/fastcgi-authorizer-4.socket max_conns=1;
server unix:/var/tmp/nginx/fastcgi-authorizer-5.socket max_conns=1;
server unix:/var/tmp/nginx/fastcgi-authorizer-6.socket max_conns=1;
server unix:/var/tmp/nginx/fastcgi-authorizer-7.socket max_conns=1;
server unix:/var/tmp/nginx/fastcgi-authorizer-8.socket max_conns=1;
}

Thanks