'\" t
.\"     Title: pg_isready
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 2021
.\"    Manual: PostgreSQL 9.6.24 Documentation
.\"    Source: PostgreSQL 9.6.24
.\"  Language: English
.\"
.TH "PG_ISREADY" "1" "2021" "PostgreSQL 9.6.24" "PostgreSQL 9.6.24 Documentation"
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.SH "NAME"
pg_isready \- check the connection status of a PostgreSQL server
.SH "SYNOPSIS"
.HP \w'\fBpg_isready\fR\ 'u
\fBpg_isready\fR [\fIconnection\-option\fR...] [\fIoption\fR...]
.SH "DESCRIPTION"
.PP
pg_isready
is a utility for checking the connection status of a
PostgreSQL
database server\&. The exit status specifies the result of the connection check\&.
.SH "OPTIONS"
.PP
\fB\-d \fR\fB\fIdbname\fR\fR
.br
\fB\-\-dbname=\fR\fB\fIdbname\fR\fR
.RS 4
Specifies the name of the database to connect to\&. The
\fIdbname\fR
can be a
connection string\&. If so, connection string parameters will override any conflicting command line options\&.
.RE
.PP
\fB\-h \fR\fB\fIhostname\fR\fR
.br
\fB\-\-host=\fR\fB\fIhostname\fR\fR
.RS 4
Specifies the host name of the machine on which the server is running\&. If the value begins with a slash, it is used as the directory for the Unix\-domain socket\&.
.RE
.PP
\fB\-p \fR\fB\fIport\fR\fR
.br
\fB\-\-port=\fR\fB\fIport\fR\fR
.RS 4
Specifies the TCP port or the local Unix\-domain socket file extension on which the server is listening for connections\&. Defaults to the value of the
\fBPGPORT\fR
environment variable or, if not set, to the port specified at compile time, usually 5432\&.
.RE
.PP
\fB\-q\fR
.br
\fB\-\-quiet\fR
.RS 4
Do not display status message\&. This is useful when scripting\&.
.RE
.PP
\fB\-t \fR\fB\fIseconds\fR\fR
.br
\fB\-\-timeout=\fR\fB\fIseconds\fR\fR
.RS 4
The maximum number of seconds to wait when attempting connection before returning that the server is not responding\&. Setting to 0 disables\&. The default is 3 seconds\&.
.RE
.PP
\fB\-U \fR\fB\fIusername\fR\fR
.br
\fB\-\-username=\fR\fB\fIusername\fR\fR
.RS 4
Connect to the database as the user
\fIusername\fR
instead of the default\&.
.RE
.PP
\fB\-V\fR
.br
\fB\-\-version\fR
.RS 4
Print the
pg_isready
version and exit\&.
.RE
.PP
\fB\-?\fR
.br
\fB\-\-help\fR
.RS 4
Show help about
pg_isready
command line arguments, and exit\&.
.RE
.SH "EXIT STATUS"
.PP
pg_isready
returns
0
to the shell if the server is accepting connections normally,
1
if the server is rejecting connections (for example during startup),
2
if there was no response to the connection attempt, and
3
if no attempt was made (for example due to invalid parameters)\&.
.SH "ENVIRONMENT"
.PP
\fBpg_isready\fR, like most other
PostgreSQL
utilities, also uses the environment variables supported by
libpq
(see
Section 32.14, \(lqEnvironment Variables\(rq, in the documentation)\&.
.SH "NOTES"
.PP
It is not necessary to supply correct user name, password, or database name values to obtain the server status; however, if incorrect values are provided, the server will log a failed connection attempt\&.
.SH "EXAMPLES"
.PP
Standard Usage:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_isready\fR
/tmp:5432 \- accepting connections
$ \fBecho $?\fR
0
.fi
.if n \{\
.RE
.\}
.PP
Running with connection parameters to a
PostgreSQL
cluster in startup:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_isready \-h localhost \-p 5433\fR
localhost:5433 \- rejecting connections
$ \fBecho $?\fR
1
.fi
.if n \{\
.RE
.\}
.PP
Running with connection parameters to a non\-responsive
PostgreSQL
cluster:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_isready \-h someremotehost\fR
someremotehost:5432 \- no response
$ \fBecho $?\fR
2
.fi
.if n \{\
.RE
.\}
.sp