</Para>

<Para>

If your site administrator has not set things up in the default way,

you may have some more work to do. For example, if the database server

machine is a remote machine, you will need to set the

<Acronym>PGHOST</Acronym> environment variable to the name of the

database server machine. The environment variable

<Acronym>PGPORT</Acronym> or <envar>PGUNIXSOCKET</envar> may also have

to be set. The bottom line is this: if you try to start an application

program and it complains that it cannot connect to the

<Application>postmaster</Application>, you should immediately consult

your site administrator to make sure that your environment is properly

set up. </Para>

If your site administrator has not set things up in the

default way, you may have some more work to do. For example, if the database

server machine is a remote machine, you

will need to set the <Acronym>PGHOST</Acronym> environment variable to the name

of the database server machine. The environment variable

<Acronym>PGPORT</Acronym> may also have to be set. The bottom line is this: if

you try to start an application program and it complains

that it cannot connect to the <Application>postmaster</Application>,

you should immediately consult your site administrator to make sure that your

environment is properly set up.

</Para>

</Chapter>

<!--

$Header: /cvsroot/pgsql/doc/src/sgml/Attic/libpq++.sgml,v 1.19 2000/11/22 01:41:12 momjian Exp $

$Header: /cvsroot/pgsql/doc/src/sgml/Attic/libpq++.sgml,v 1.20 2000/11/30 23:20:50 tgl Exp $

-->

<chapter id="libpqplusplus">

<listitem>

<para>

<envar>PGHOST</envar> sets the default server name.

If it begins with a slash, it is used

as the directory for the unix domain socket.

If this begins with a slash, it specifies Unix-domain communication

rather than TCP/IP communication; the value is the name of the

directory in which the socket file is stored (default "/tmp").

</para>

</listitem>

<listitem>

<para>

<envar>PGPORT</envar> sets the default port or local Unix domain socket

file extension for communicating with the <productname>Postgres</productname>

backend.

</para>

</listitem>

<listitem>

<para>

<envar>PGUNIXSOCKET</envar> sets the Unix domain socket

directory for communicating with the <productname>Postgres</productname>

backend.

<envar>PGPORT</envar> sets the default TCP port number or Unix-domain

socket file extension for communicating with the

<productname>Postgres</productname> backend.

</para>

</listitem>

<listitem>

<!--

$Header: /cvsroot/pgsql/doc/src/sgml/libpq.sgml,v 1.50 2000/11/3018:34:36 petere Exp $

$Header: /cvsroot/pgsql/doc/src/sgml/libpq.sgml,v 1.51 2000/11/3023:20:50 tgl Exp $

-->

<chapter id="libpq-chapter">

<listitem>

<para>

Name of host to connect to.

Using this parameter causes a hostname look-up. See hostaddr.

If it begins with a slash, it is used

as the directory for the unix domain socket.

If this begins with a slash, it specifies Unix-domain communication

rather than TCP/IP communication; the value is the name of the

directory in which the socket file is stored.

The default is to connect to a Unix-domain socket in

<filename>/tmp</filename>.

</para>

</listitem>

</varlistentry>

machine at hostaddr.

</para>

<para>

Withoutboth a host nameand host address, libpq will connect using a

Withouteither a host nameor host address, libpq will connect using a

local Unix domain socket.

</para>

</listitem>

<listitem>

<para>

<envar>PGHOST</envar> sets the default server name.

If it beings with a slash, it is used as the directory for the unix domain

socket.

If this begins with a slash, it specifies Unix-domain communication

rather than TCP/IP communication; the value is the name of the

directory in which the socket file is stored (default "/tmp").

</para>

</listitem>

<listitem>

<para>

<envar>PGPORT</envar> sets the default port for communicating with

the <productname>Postgres</productname> backend.

<envar>PGPORT</envar> sets the default TCP port number or Unix-domain

socket file extension for communicating with the

<productname>Postgres</productname> backend.

</para>

</listitem>

<listitem>

<!--

$Header: /cvsroot/pgsql/doc/src/sgml/ref/pg_dump.sgml,v 1.25 2000/11/22 01:41:13 momjian Exp $

$Header: /cvsroot/pgsql/doc/src/sgml/ref/pg_dump.sgml,v 1.26 2000/11/30 23:20:50 tgl Exp $

Postgres documentation

-->

<varlistentry>

<term><computeroutput>

Connection to database 'template1' failed.

connectDB() failed: Is the postmaster running and accepting connections

at 'UNIX Socket' on port '<replaceable class="parameter">port</replaceable>'?

connectDBStart() -- connect() failed: No such file or directory

Is the postmaster running locally

and accepting connections on Unix socket '/tmp/.s.PGSQL.5432'?

</computeroutput></term>

<listitem>

<para>

<!--

$Header: /cvsroot/pgsql/doc/src/sgml/ref/pg_dumpall.sgml,v 1.15 2000/11/22 01:41:13 momjian Exp $

$Header: /cvsroot/pgsql/doc/src/sgml/ref/pg_dumpall.sgml,v 1.16 2000/11/30 23:20:50 tgl Exp $

Postgres documentation

-->

<varlistentry>

<term><computeroutput>

Connection to database 'template1' failed.

connectDB() failed: Is the postmaster running and accepting connections at 'UNIX Socket' on port '<replaceable class="parameter">port</replaceable>'?

connectDBStart() -- connect() failed: No such file or directory

Is the postmaster running locally

and accepting connections on Unix socket '/tmp/.s.PGSQL.5432'?

</computeroutput></term>

<listitem>

<para>

<varlistentry>

<term><computeroutput>

Connection to database 'template1' failed.

connectDB() failed: Is the postmaster running and accepting connections

at 'UNIX Socket' on port '<replaceable class="parameter">port</replaceable>'?

connectDBStart() -- connect() failed: No such file or directory

Is the postmaster running locally

and accepting connections on Unix socket '/tmp/.s.PGSQL.5432'?

</computeroutput></term>

<listitem>

<para>

<!--

$Header: /cvsroot/pgsql/doc/src/sgml/ref/postmaster.sgml,v 1.17 2000/11/28 23:27:54 tgl Exp $

$Header: /cvsroot/pgsql/doc/src/sgml/ref/postmaster.sgml,v 1.18 2000/11/30 23:20:50 tgl Exp $

Postgres documentation

-->

<refentry id="APP-POSTMASTER">

<docinfo>

<date>2000-11-12</date>

<date>2000-11-30</date>

</docinfo>

<refmeta>

<arg>-F</arg>

<arg>-h <replaceable>hostname</replaceable></arg>

<arg>-i</arg>

<arg>-k <replaceable>filename</replaceable></arg>

<arg>-k <replaceable>directory</replaceable></arg>

<arg>-l</arg>

<arg>-N <replaceable>max-connections</replaceable></arg>

<arg>-o <replaceable>extra-options</replaceable></arg>

starts it needs to know the location of the database cluster files

(<quote>data area</quote>). This is done with the

<option>-D</option> invocation option or the <envar>PGDATA</envar>

environment variable, there is no default. More than one

environment variable; there is no default. More than one

postmaster process can run on a system at one time, as long as they

use different data areas and differentport numbers (see below). A

data area is created with <xref linkend="app-initdb"

use different data areas and differentcommunication ports (see below).

Adata area is created with <xref linkend="app-initdb"

endterm="app-initdb-title">.

</para>

<para>

Specifies the TCP/IP hostname or address on which the

<application>postmaster</application> is to listen for

connections from client applications. Defaults to the value

of the <envar>PGHOST</envar> environment variable, or if

<envar>PGHOST</envar> is not set, it defaults to listening on

all configured addresses (including localhost).

connections from client applications. Defaults to

listening on all configured addresses (including localhost).

</para>

</listitem>

</varlistentry>

</varlistentry>

<varlistentry>

<term>-k <replaceable class="parameter">filename</replaceable></term>

<term>-k <replaceable class="parameter">directoryname</replaceable></term>

<listitem>

<para>

Specifies the directoryfor Unixdomain socket on which the

Specifies the directoryof the Unix-domain socket on which the

<application>postmaster</application> is to listen for

connections from client applications. Defaults to the value

of the <envar>PGUNIXSOCKET</envar> environment variable, or if

<envar>PGUNIXSOCKET</envar> is not set, then defaults to a

file in <filename>/tmp</filename>.

connections from client applications. The default is normally

<filename>/tmp</filename>, but can be changed at build time.

</para>

</listitem>

</varlistentry>

<!--

$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.39 2000/11/2520:33:47 tgl Exp $

$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.40 2000/11/30 23:20:50 tgl Exp $

-->

<Chapter Id="runtime">

<para>

<screen>

connectDB() -- connect() failed: Connection refused

Is the postmaster running (with -i) at 'server.joe.com' and accepting connections on TCP/IP port'5432'?

Is the postmaster running (with -i) at 'server.joe.com' and accepting connections on TCP/IP port 5432?

</screen>

This is the generic <quote>I couldn't find a server to talk

to</quote> failure. It looks like the above when TCP/IP

Unix-socket communication to a local postmaster:

<screen>

connectDB() -- connect() failed: No such file or directory

Is the postmaster runningat 'localhost'and accepting connections on Unix socket '5432'?

Is the postmaster runninglocallyand accepting connections on Unix socket '/tmp/.s.PGSQL.5432'?

</screen>

</para>

</varlistentry>

<varlistentry>

<term>UNIXSOCKET (<type>string</type>)</term>

<term>UNIX_SOCKET_DIRECTORY (<type>string</type>)</term>

<listitem>

<para>

Specifies the directory of the Unixdomain socket on which the

Specifies the directory of the Unix-domain socket on which the

<application>postmaster</application> is to listen for

connections from client applications. Defaults to the value

of the <envar>PGUNIXSOCKET</envar> environment variable, or if

<envar>PGUNIXSOCKET</envar> is not set, then defaults to

<filename>/tmp</filename>.

connections from client applications. The default is normally

<filename>/tmp</filename>, but can be changed at build time.

</para>

</listitem>

</varlistentry>

<para>

Specifies the TCP/IP hostname or address on which the

<application>postmaster</application> is to listen for

connections from client applications. Defaults to the value

of the <envar>PGHOST</envar> environment variable, or if

<envar>PGHOST</envar> is not set, it defaults to listening on

all configured addresses (including localhost).

</para>

<para>

If you use a hostname do not try to run multiple instances of

<application>postmaster</application> on the same IP address

but different ports. Doing so will result in them attempting

(incorrectly) to use the same shared memory segments. Also,

if you use a hostname, all of the host's IP addresses on which

<application>postmaster</application> instances are listening

must be distinct in the two last octets.

</para>

<para>

If you do not use this option, then each instance must listen

on a different port.

connections from client applications. Defaults to

listening on all configured addresses (including localhost).

</para>

</listitem>

</varlistentry>

<entry>tcpip_socket = on</entry>

<entry></entry>

</row>

<row>

<entry>-k <replaceable>x</replaceable></entry>

<entry>unix_socket_directory = <replaceable>x</replaceable></entry>

<entry></entry>

</row>

<row>

<entry>-l</entry>

<entry>ssl = on</entry>

<!--

$Header: /cvsroot/pgsql/doc/src/sgml/start.sgml,v 1.14 2000/11/13 15:18:07 momjian Exp $

$Header: /cvsroot/pgsql/doc/src/sgml/start.sgml,v 1.15 2000/11/30 23:20:50 tgl Exp $

-->

<chapter id="start">

will need to set the <acronym>PGHOST</acronym> environment

variable to the name

of the database server machine. The environment variable

<acronym>PGPORT</acronym>or <acronym>PGUNIXSOCKET</acronym>may also have to be set.

<acronym>PGPORT</acronym> may also have to be set.

The bottom line is this: if

you try to start an application program and it complains

that it cannot connect to the <application>postmaster</application>,

<programlisting>

% psql template1

Connection to database 'postgres' failed.

connectDB() failed:Is the postmaster runningand accepting connections

at 'UNIX Socket'onport '5432'?

psql: connectDBStart() -- connect() failed: No such file or directory

Is the postmaster runninglocally

and accepting connectionsonUnix socket '/tmp/.s.PGSQL.5432'?

</programlisting>

or

<programlisting>

% psql -h localhost template1

Connection to database 'postgres' failed.

connectDB() failed:Is the postmaster runningand accepting TCP/IP

(with -i) connections at 'localhost'on port'5432'?

psql: PQconnectPoll() -- connect() failed: Connection refused

Is the postmaster running(with -i) at 'localhost'

and accepting connectionsonTCP/IPport 5432?

</programlisting>

it is usually because

NetServer= true;

break;

case'k':

UnixSocketDir=optarg;

break;

printf(" -F turn fsync off\n");

printf(" -h HOSTNAME host name or IP address to listen on\n");

printf(" -i enable TCP/IP connections\n");

printf(" -kFILENAMEUnixdomain socket location\n");

printf(" -kDIRECTORY Unix-domain socket location\n");

printf(" -l enable SSL connections\n");