Re: Patch: Implement failover on libpq connect level.

From: pgsql-hackers-owner@postgresql.org
> [mailto:pgsql-hackers-owner@postgresql.org] On Behalf Of Robert Haas
> Great, committed.  There's still potentially more work to be done here,
> because my patch omits some features that were present in Victor's original
> submission, like setting the failover timeout, optionally randomizing the
> order of the hosts, and distinguishing between master and standby servers;
> Victor, or anyone, please feel free to submit separate patches for those
> things.

The attached patch fixes some bugs and make a clarification for doc.  Could you check and test the authentication stuff
asI don't have an environment at hand?
 

(1) fe-connect.c
There was a memory leak.

(2) fe-secure_openssl.c, fe-auth.c
GSSAPI/SSPI/SSL authentication requires the target host name, but the code uses conn->pghost which contains a
comma-separatedlist of host names.
 

(3) libpq.sgml
Added sentences to clarify connect_timeout when it is used with multiple hosts.

BTW, let me two questions.

Q1: Is there any reason why hostaddr doesn't accept multiple IP addresses?

Q2: pg_isready (and hence PQping() family) reports success when one host is alive and other hosts are down.  Is this
intended? I think this behavior is correct.
 
e.g. host1 is down and host2 is alive.
$ pg_isready -h host1,host2
host1,host2:5450 - accepting connections
$ echo $?
0

Regards
Takayuki Tsunakawa