Postgresql – posgresql9.4 remote connection fail

The line in your netstat report shows that the database is only listening on localhost:5432 (127.0.0.1) for incoming tcp connections.

Proto Recv-Q Send-Q Local Address   Foreign Address  State   PID/Program name
tcp        0      0 127.0.0.1:5432  0.0.0.0:*        LISTEN  3561/postgres

So it can only accept local tcp connections regardless of what permissions you've specified in pg_hba.conf. pg_hba.conf only specifies allowed connections, but does not specify what interfaces your service will listen to.

The addresses the server listens on is specified with the listen_addresses GUC in postgresql.conf. If you want the server to listen for remote connections you should specify the ip(s) you want it to listen on or * to listen on all available interfaces on the host.

To have your postgresql server listen on all interfaces on the host, you should have the following line in postgresql.conf:

listen_addresses = '*'

No buffer space available corresponds to a network error where the client is not enable to allocate the resources to initiate a connection.

Generally, this means that there are other programs holding too many connection handles (sockets).

According to a post on IBM developerWorks:

This error can occur on Windows, particularly around socket operations. The error is translated from the Winsock error code WSAENOBUFS, 10055. The most common cause of this error is that Windows is configured for the default maximum of 5,000 in-use ports. This can be monitored by watching netstat or perfmon and can be changed with the MaxUserPort registry parameter.

A more advanced cause for this error is non-paged pool exhaustion[...]

Uninstalling software will solve the problem for good only if that software was responsible for consuming too many simultaneous connections in the first place. Otherwise, getting back some of these resources may happen as a side-effect of say, rebooting, or just waiting a bit so that TCP connections in TIME_WAIT state disappear, or individually terminating programs that held these connections open.