ngx_http_upstream_dynamic_module

This module provides the functionality to resolve domain names into IP addresses in an upstream at run-time.

Examples

upstream backend {
    dynamic_resolve fallback=stale fail_timeout=30s;
    server a.com;
    server b.com;
}
server {
    ...
    location / {
        proxy_pass http://backend;
    }
}

Directive

Syntax: dynamic_resolve [fallback=stale|next|shutdown] [fail_timeout=time]
Default: -
Context: upstream.

Enable dynamic DNS resolving functionality in an upstream.

The 'fallback' parameter specifies what action to take if a domain name can not be resolved into an IP address:

The 'fail_timeout' parameter specifies how long time tengine considers the DNS server as unavailiable if a DNS query fails for a server in the upstream. In this period of time, all requests comming will follow what 'fallback' specifies.