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pg_isready
pg_isready is a core utility which checks the connection status of a PostgreSQL server.
pg_isready was added in PostgreSQL 9.3 .
Usage
pg_isready uses the provided connection details to initiate a server connection, and determine the server status from the server's response (or lack thereof).
Note that pg_isready never actually connects to the database and does not require a valid database, user or password to be provided to check the server's response. However the server will log the validity of the connection attempt.
Change history
- PostgreSQL 9.3
- added (commit ac2e9673)
pg_isready has not been substantially modified since it was introduced in PostgreSQL 9.3.
Examples
Basic usage example for pg_isready:
postgres $ pg_isready -d 'user=postgres dbname=postgres host=localhost port=5432' localhost:5432 - accepting connections postgres $ echo $? 0
The log file will contain an entry like the following (assuming log_connections is set to on):
2022-09-02 10:02:25.015 UTC [31325] LOG: connection received: host=127.0.0.1 port=36628 2022-09-02 10:02:25.015 UTC [31325] LOG: connection authorized: user=postgres database=postgres application_name=pg_isready
Attempting to connect to a server with an invalid username and/or database name:
postgres $ pg_isready -d 'user=nosuchuser dbname=nosuchdb host=localhost port=5432' localhost:5432 - accepting connections postgres $ echo $? 0
The log file will contain an entry like the following:
2022-09-01 10:12:18.711 UTC [32711] LOG: connection authorized: user=nosuchuser database=nosuchdb application_name=pg_isready 2022-09-01 10:12:18.711 UTC [32711] FATAL: role "nosuchuser" does not exist
Attempting to connect to a port where a server is not currently running:
postgres $ pg_isready -d 'user=postgres dbname=postgres host=localhost port=9999' localhost:9999 - no response postgres $ echo $? 2
References
- PostgreSQL documentation: pg_isready