[Pgpool-hackers] removing backend_socket_dir parameter ?

[Tatsuo Ishii]

> Le 04/01/2011 15:38, Jehan-Guillaume (ioguix) de Rorthais a écrit :
>> Le 04/01/2011 15:13, Guillaume Lelarge a écrit :
>>> Hi,
>> 
>>> Le 04/01/2011 14:27, Jehan-Guillaume (ioguix) de Rorthais a écrit :
>>>> [...]
>>>> pgPool is currently using the parameter "backend_socket_dir" to define where it
>>>> can find the backend unix socket files.
>>>>
>>>> However, from the libpq world, we just use one parameter for both unix or inet
>>>> socket: host. If this parameter starts with '/', then this is a unix socket. All
>>>> other values are inet connections. See:
>>>>
>>>> http://www.postgresql.org/docs/9.0/static/libpq-connect.html#LIBPQ-CONNECT-HOST
>>>>
>>>> Back in pgPool world, the equivalent parameter is "backend_hostnameN". So, when
>>>> I was setting up a dev environment yesterday, I naturally set this parameter  to
>>>> my unix path (I'm using Debian) and end up with a hostname resolution error.
>>>>
>>>> So you'll find in attachment a patch to remove the "backend_socket_dir"
>>>> parameter and use the libpq policy. Moreover, on empty "backend_hostnameN"
>>>> value, the patch fall back to DEFAULT_SOCKET_DIR.
>>>>
>> 
>>> This patch is really interesting. This is something I had on my todo
>>> list for quite some time.
>> 
>> Glad to hear that :)
>> I wasn't the only one wondering about this then :)
>> 
>>>> I realize it will break compatibility with older configuration file. But in a
>>>> first step, I prefer something clean and start discussing this issue with you if
>>>> you really mind this.
>>>>
>> 
>>> On the configuration file, compatibility of configuration file is never
>>> garantied. So I don't think this is such an issue. We need to make it
>>> clear that the parameter has a new mail.
>> 
>> s/new mail/new name/
>> 
>> well, it's not a new name, we just drop one and promote an existing one to deal
>> with both unix and inet socket :)
>> 
>>> If we really want to maintain the compatibility on this issue, we could
>>> still support the old parameter during two or three major releases. I
>>> guess we need to put a warning in the log to say "hey guy, you're still
>>> using that old obsolete configuration parameter, you should better
>>> change with this one".
>> 
>> Yeah. What I have in mind is :
>>   if backend_hostnameN == ''
>>     if not backend_socket_dir
>>       backend_hostnameN = DEFAULT_SOCKET_DIR
>>     else
>>       log « please stop using that »
>>       backend_hostnameN = backend_socket_dir
>> 
>> But really, I would prefer to drop backend_socket_dir and keep the code clean.
>> 
> 
> You can't have it both ways. Either you please your users, or you please
> your developpers. I think we should do the former.

Agreed. I learned it in a hard way:-)

Now I think the idea is great and am looking forward to accepting for
the next release.
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp