pg_isready
pg_isready
pg_isready - check the connection status of a PostgreSQL server
Synopsis
pg_isready
[
connection-option
...] [
option
...]
Description
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.
Options
-
-d
dbname
--dbname=
dbname
-
Specifies the name of the database to connect to. The
dbname
can be a connection string . If so, connection string parameters will override any conflicting command line options. -
-h
hostname
--host=
hostname
-
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.
-
-p
port
--port=
port
-
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
PGPORT
environment variable or, if not set, to the port specified at compile time, usually 5432. -
-q
--quiet
-
Do not display status message. This is useful when scripting.
-
-t
seconds
--timeout=
seconds
-
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.
-
-U
username
--username=
username
-
Connect to the database as the user
username
instead of the default. -
-V
--version
-
Print the pg_isready version and exit.
-
-?
--help
-
Show help about pg_isready command line arguments, and exit.
Exit Status
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).
Environment
pg_isready
, like most other
PostgreSQL
utilities,
also uses the environment variables supported by
libpq
(see
Section 32.15
).
The environment variable
PG_COLOR
specifies whether to use
color in diagnostic messages. Possible values are
always
,
auto
and
never
.
Notes
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.
Examples
Standard Usage:
$
pg_isready
/tmp:5432 - accepting connections
$
echo $?
0
Running with connection parameters to a PostgreSQL cluster in startup:
$
pg_isready -h localhost -p 5433
localhost:5433 - rejecting connections
$
echo $?
1
Running with connection parameters to a non-responsive PostgreSQL cluster:
$
pg_isready -h someremotehost
someremotehost:5432 - no response
$
echo $?
2