Re: duplicate connection failure messages

Magnus Hagander wrote:
> On Fri, Nov 12, 2010 at 15:02, Bruce Momjian <bruce@momjian.us> wrote:
> > Tom Lane wrote:
> >> Bruce Momjian <bruce@momjian.us> writes:
> >> > I have developed the attached patch to report whether IPv4 or IPv6 are
> >> > being used.
> >>
> >> What's the use of that exactly? ?It doesn't really respond to Peter's
> >> concern, I think.
> >
> > Peter liked:
> >
> >> And I agree it's not very friendly in this specific case - I
> >> wonder if we should log it as "localhost (127.0.0.1) and "localhost
> >> (::1)" (and similar for any other case that returns more than one
> >> address).
> >
> > What this will show is:
> >
> > ? ? ? ?localhost (IPv4)
> > ? ? ? ?localhost (IPv6)
> >
> > Is that good? ?I can't figure out how to do ::1 because when you supply
> > a host _name_, there is no reverse mapping done. ?Looking at the code,
> > we test for a host name, then a host ip, and don't assume they are both
> > set.
> 
> The address is in conn->raddr, no? When you've put in a host name, we
> do a forward lookup, so conn->raddr should contain ::1 already? You
> only need the reverse mapping to get the "localhost" part, if I read
> the code correctly?

OK, I found out how to get the IP address with the attached patch.  The
problem is that only pghost is set, never pghostaddr.  I am not even
sure how that would get set for this code because my tests show it is
not:

	$ psql -h localhost test
	pghost = localhost
-->	pghostaddr = (null)
	psql: could not connect to server: Connection refused
	        Is the server running on host "localhost" (127.0.0.1) and accepting
	        TCP/IP connections on port 5432?
	
	$ psql -h 127.0.0.1 test
	pghost = 127.0.0.1
	pghostaddr = (null)
	psql: could not connect to server: Connection refused
	        Is the server running on host "127.0.0.1" and accepting
	        TCP/IP connections on port 5432?

To get this to work, I compared pghost with the raddr value, and printed
the IP address if it was not already printed.  There is still a problem
about threading that I can fix.

Is this what we want?

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +