Re: TCP keepalive support for libpq

>>> ISTM that the default behavior should be keep alives disabled, as it is
>>> now, and those wanting it can just set it in their apps:
>>>
>>> setsockopt(PQsocket(conn), SOL_SOCKET, SO_KEEPALIVE, ...)
>> I disagree. I have clients who have problems with leftover client connections
>> due to server host failures. They do not write apps in C. For a non-default
>> change to be effective we would need to have all the client drivers, eg JDBC,
>> psycopg, DBD-DBI, and the apps like psql make changes to turn it on. Adding
>> this option as a non-default will not really help.
> 
> Yes, that's definitely the use-case. PQsocket() will work fine for C apps only.
> 
> But it should work fine as an option, no? As long as you can specify
> it on the connection string - I don't think there are any interfaces
> that won't take a connection string?
> 

Perl and python appear to have the same abilities as C.  I don't use either of 
these drivers but I *think* the below would work:

DBD:DBI
setsockopt($dbh->pg_socket(), ...);

psycopg
conn.cursor().socket().setsockopt(...);

Although, I think Dave's comments have made me change my mind about this patch.  Looks like it serves a good purpose.
Thatsaid, there is no guarentee the 
 
driver will implement the new feature ... JDBC seems to lack the ability to get 
the backing Socket object but java can set socket options.  Maybe a JDBC kong fu 
master knows how to do this.

-- 
Andrew Chernow
eSilo, LLC
every bit counts
http://www.esilo.com/