pg_autoctl run(1)

Usage

This commands starts the processes needed to run a monitor node or a keeper node, depending on the configuration file that belongs to the --pgdata option or PGDATA environment variable.

usage: pg_autoctl run  [ --pgdata --name --hostname --pgport ]
--pgdata      path to data directory
--name        pg_auto_failover node name
--hostname    hostname used to connect from other nodes
--pgport      PostgreSQL's port number

Overview

When registering Postgres nodes to the pg_auto_failover monitor using the pg_autoctl create postgres command, the nodes are registered with metadata: the node name, hostname and Postgres port.

The node name is used mostly in the logs and pg_autoctl show state commands and helps human administrators of the formation.

The node hostname and pgport are used by other nodes, including the pg_auto_failover monitor, to open a Postgres connection.

Both the node name and the node hostname and port can be changed after the node registration by using either this command (pg_autoctl run) or the pg_autoctl config set command.

Options

--pgdata: Location of the Postgres node being managed locally. Defaults to the environment variable PGDATA. Use --monitor to connect to a monitor from anywhere, rather than the monitor URI used by a local Postgres node managed with pg_autoctl.

--name

Node name used on the monitor to refer to this node. The hostname is a technical information, and given Postgres requirements on the HBA setup and DNS resolution (both forward and reverse lookups), IP addresses are often used for the hostname.

The --name option allows using a user-friendly name for your Postgres nodes.

--hostname

Hostname or IP address (both v4 and v6 are supported) to use from any other node to connect to this node.

When not provided, a default value is computed by running the following algorithm.

1.: We get this machine's "public IP" by opening a connection to the given monitor hostname or IP address. Then we get TCP/IP client address that has been used to make that connection.

2.: We then do a reverse DNS lookup on the IP address found in the previous step to fetch a hostname for our local machine.

3.: If the reverse DNS lookup is successful , then pg_autoctl does a forward DNS lookup of that hostname.

When the forward DNS lookup response in step 3. is an IP address found in one of our local network interfaces, then pg_autoctl uses the hostname found in step 2. as the default --hostname. Otherwise it uses the IP address found in step 1.

You may use the --hostname command line option to bypass the whole DNS lookup based process and force the local node name to a fixed value.

--pgport: Postgres port to use, defaults to 5432.

Releases

2 releases since Debian 12 (Bookworm); the text changed 1 time.

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