Provided by: postgresql-client-9.5_9.5.2-1_amd64 bug


       pg_isready - check the connection status of a PostgreSQL server


       pg_isready [connection-option...] [option...]


       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.


       -d dbname
           Specifies the name of the database to connect to.

           If this parameter contains an = sign or starts with a valid URI prefix (postgresql://
           or postgres://), it is treated as a conninfo string. See Section 31.1.1, “Connection
           Strings”, in the documentation for more information.

       -h 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
           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.

           Do not display status message. This is useful when scripting.

       -t 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
           Connect to the database as the user username instead of the default.

           Print the pg_isready version and exit.

           Show help about pg_isready command line arguments, and exit.


       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).


       pg_isready, like most other PostgreSQL utilities, also uses the environment variables
       supported by libpq (see Section 31.14, “Environment Variables”, in the documentation).


       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.


       Standard Usage:

           $ pg_isready
           /tmp:5432 - accepting connections
           $ echo $?

       Running with connection parameters to a PostgreSQL cluster in startup:

           $ pg_isready -h localhost -p 5433
           localhost:5433 - rejecting connections
           $ echo $?

       Running with connection parameters to a non-responsive PostgreSQL cluster:

           $ pg_isready -h someremotehost
           someremotehost:5432 - no response
           $ echo $?