Hi,
just a question... is there some sort of internal nginx DNS cache? I have a strange problem here...

basic scenario: i have multiple domains (like vhost 1) with different domains (my.domain.com, www.domainx.com etc., just example names). But all of them proxy_pass to the same intermediate vhost (vhost 2), which then sends the requests to the backends. A resolver.conf is used, using the providers DNS servers.

all configs a bit simplified...
vhost 1:
server {
listen 1.2.3.4:443 ssl;
server_name my.domain.com; # or www.domainx.com etc.
location / {
proxy_set_header proxy.otherdomain.com; # some other domains running on 2.3.4.5:443, so set the header here
proxy_pass https://proxy.otherdomain.com;
}
}

vhost 2:
server {
listen 2.3.4.5:443 ssl;
server_name proxy.otherdomain.com;
location / {
proxy_pass http://my-backends; # my-backends is an upstreamreferring to 2 identical backends
}
}

When i change the IP address of proxy.otherdomain.com in the providers DNS to e.g. 3.4.5.6 and create a vhost 3 (identical to vhost 2, but with this new IP address) on a different server (all the vhosts like vhost 1 remain unchanged), the operating system soon receives the changes (checked with ping, dig etc.) - but nginx somehow still uses the old IP (2.3.4.5 instead of 3.4.5.6) address, even after days (DNS ttl: 60s). nginx restart doesn't help.

Hope you were able to follow this long text... but is there some sort of nginx-internal DNS cache? DNS changes work (tested external and on the debian server), but only nginx doesn't seem to care and still uses an old IP.


thx,
Hubert