Re: Problem with libpq3 & postgresql8

Michael Fuhr wrote:
> On Wed, Sep 21, 2005 at 04:18:33PM +0300, Devrim GUNDUZ wrote:
>
>>On Wed, 21 Sep 2005, Alex R. Mosteo wrote:
>>
>>>I have a client program which worked ok, using libpq3 agains a 7.4
>>>database. Both linux versions. The client and server are in separate
>>>machines connecting via TCP/IP.
>>>
>>>I've just updated the database to 8.0, and the client program now can't
>>>connect. There's no error message, it simply gets stuck when doing the
>>>connection call and remains so indefinitely.
>>>
>>>Is this a known incompatibility? If not, any suggestions on what to try?
>>
>>libpq version was changed in 8.0.2.
>>
>>If you are using Red Hat / Fedora Core, install this package to solve the
>>problem:
>
>
> While it's a good idea to upgrade the libraries to match the server,
> a 7.4 libpq should nevertheless be able to connect to an 8.0 server
> (unless the server demands a client certificate, in which case the
> connection should fail instead of hanging).  What's your theory
> about why the 7.4 library is hanging on the connection attempt?
>
> Alex, are you sure it's the connection call that's stuck?  Have you
> used a debugger or added print statements immediately before and
> after the connection attempt?  Have you done a process trace or
> network sniff to see what's happening when the program hangs?

The most I've checked is adding print statements before and after the
call. There's an extra layer of error source, which is that the call is
done from Ada through a binding to the C library. So it could be that
the Ada layer is behaving wrongly with an unexpected error from the C
layer. But then, I would expect an exception and not a hang. I plan on
conducting some more detailed tests if upgrading libpq fails.

That said, the only thing that I've changed is the database, which is
now the one that ships with kubuntu 5.10 experimental, 8.0.3 according
to psql --version.

About the certificate thing, I'm not sure what you mean, but I've
configured the pg_hba.conf file useing hostnossl. I see this line in the
server log:

LOG:  no se pudo aceptar una conexión SSL: se detectó EOF

Which translates to: "Couldn't accept a SSL connection: EOF detected"

but this message only appears after I kill the client process, which
could mean that indeed the connection is alive and hung.

I don't understand where SSL comes into play. Is there any parameter
that I should be adding to the client connection string to disable it?
My connection string is like:

"host=xxxxx.homeip.net dbname=xxx user=xxxxx password=xxxxxx"

Thanks for your help,

Alex.