Re: Patch: Implement failover on libpq connect level.

On Thu, Oct 27, 2016 at 11:15 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> Thanks. Here's a new version with a fix for that issue and also a fix
> for PQconnectionNeedsPassword(), which was busted in v1.
I did some more testing of the patch for both URI and (host, port)
parameter pairs. I did test for ipv4, ipv6, UDS type of sockets, Also
tested different password using .pgpass. I did not see any major issue
with. All seems to work as defined. Tested the behaviors of API PQport,
PQhost, PQpass, PQreset all works as defined.

I also have following observation which can be considered if it is valid.

1. URI do not support UDS, where as (host,port) pair support same.
But there is one problem with this, instead of reporting it, we discard the
URI input (@conninfo_uri_parse_options) and try to connect to default unix
socket

[mithun(at)localhost bin]$ ./psql postgres:///home/mithun:5555,
127.0.0.1:5555/postgres -U mithun
psql: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.5432"?
server is running on both the sockets.

2. If we fail to connect we get an error message for each of the addrinfo
we tried to connect, wondering if we could simplify same. Just a suggestion.
[mithun(at)localhost bin]$ ./psql postgres://,,,,,,,/postgres
psql: could not connect to server: Connection refused
Is the server running on host "" (::1) and accepting
TCP/IP connections on port 5432?
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?
could not connect to server: Connection refused
Is the server running on host "" (::1) and accepting
TCP/IP connections on port 5432?
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?
could not connect to server: Connection refused
Is the server running on host "" (::1) and accepting
TCP/IP connections on port 5432?
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?
could not connect to server: Connection refused
Is the server running on host "" (::1) and accepting
TCP/IP connections on port 5432?
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?
could not connect to server: Connection refused
Is the server running on host "" (::1) and accepting
TCP/IP connections on port 5432?
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?
could not connect to server: Connection refused
Is the server running on host "" (::1) and accepting
TCP/IP connections on port 5432?
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?
could not connect to server: Connection refused
Is the server running on host "" (::1) and accepting
TCP/IP connections on port 5432?
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?
could not connect to server: Connection refused
Is the server running on host "" (::1) and accepting
TCP/IP connections on port 5432?
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?

--
Thanks and Regards
Mithun C Y
EnterpriseDB: http://www.enterprisedb.com