There are situations in which the upstream server cannot respond to a request. In these cases, NGINX can be configured to supply a document from its local disk:
server {
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root share/examples/nginx/html;
}
}Or it can also be configured from an external site:
server {
error_page 500 http://www.example.com/maintenance.html;
}When proxying to a set of upstream servers, you may want to define an extra upstream as being a fallback server, to handle requests when the others cannot. This is useful in scenarios when the fallback server is able to deliver a customized response based on the requested URI:
upstream app {
server 127.0.0.1:9000;
server 127.0.0.1:9001;
server 127.0.0.1:9002;
}
server {
location / {
error_page 500 502 503 504 = @fallback;
proxy_pass http://app;
}
location @fallback {
proxy_pass http://127.0.0.1:8080;
}
}The =...