Nginx reverse proxy crash when dns unavailable

Gabriel Ramuglia gabe at
Fri Oct 23 00:10:53 MSD 2009

I would say I'm seeing a similar issue. I don't know if it hard locks
after one failed request or if it takes several, but, I do see a
continued lockup on an nginx worker if that worker encounters a
failure condition once. One would hope the worker would become
responsive again once the upstream service (apache or dns) becomes
responsive again, but it does not.

However, in your case, if Nginx tries to start before it has an ip
address to bind to, yes, you can expect it not to work. At the very
least, nginx can only bind to the addresses on the system, so you'll
need to start / restart nginx after you've completed DHCP.

On Thu, Oct 22, 2009 at 12:53 PM, masom <nginx-forum at> wrote:
> But shoulnd't nginx start anyway if the end point is not responding and just try to reach it anyway?
> I can't really see why it would need to stop or crash when either the endpoint (apache) or the dns system is unavailable.
> Yes it should display 5xx errors saying the endpoint is unreachable (dns or server failure / not-responding) but nginx should not "lock up" after 1 bad answer.
> Current problem:
> unit starts
> dhcp kicks in
> nginx get started before dhcp process is completed
> nginx realize that is not reachable (dns settings are not yet set by dhcp)
> nginx exits
> Browser on unit starts, says address is unreachable (as nginx did not start).
> Shouldn't nginx just attempt to connect to the end point as requests are coming in?
> The solution we consider is the hosts file that would always point to a static ip for the content server, but would be a little management problem as we are deploying in several different location with different networks.
> Posted at Nginx Forum:,15995,16042#msg-16042

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