pg_autoctl show state

pg_autoctl show state - Prints monitor’s state of nodes in a given formation and group

Synopsis

This command outputs the current state of the formation and groups registered to the pg_auto_failover monitor:

usage: pg_autoctl show state  [ --pgdata --formation --group ]

--pgdata      path to data directory
--monitor     pg_auto_failover Monitor Postgres URL
--formation   formation to query, defaults to 'default'
--group       group to query formation, defaults to all
--local       show local data, do not connect to the monitor
--watch       display an auto-updating dashboard
--json        output data in the JSON format

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.

--monitor

Postgres URI used to connect to the monitor. Must use the autoctl_node username and target the pg_auto_failover database name. It is possible to show the Postgres URI from the monitor node using the command pg_autoctl show uri.

--formation

List the events recorded for nodes in the given formation. Defaults to default.

--group

Limit output to a single group in the formation. Default to including all groups registered in the target formation.

--local

Print the local state information without connecting to the monitor.

--watch

Take control of the terminal and display the current state of the system and the last events from the monitor. The display is updated automatically every 500 milliseconds (half a second) and reacts properly to window size change.

Depending on the terminal window size, a different set of columns is visible in the state part of the output. See pg_autoctl watch.

--json

Output a JSON formated data instead of a table formatted list.

Description

The pg_autoctl show state output includes the following columns:

  • Name

    Name of the node.

  • Node

    Node information. When the formation has a single group (group zero), then this column only contains the nodeId.

    Only Citus formations allow several groups. When using a Citus formation the Node column contains the groupId and the nodeId, separated by a colon, such as 0:1 for the first coordinator node.

  • Host:Port

    Hostname and port number used to connect to the node.

  • TLI: LSN

    Timeline identifier (TLI) and Postgres Log Sequence Number (LSN).

    The LSN is the current position in the Postgres WAL stream. This is a hexadecimal number. See pg_lsn for more information.

    The current timeline is incremented each time a failover happens, or when doing Point In Time Recovery. A node can only reach the secondary state when it is on the same timeline as its primary node.

  • Connection

    This output field contains two bits of information. First, the Postgres connection type that the node provides, either read-write or read-only. Then the mark ! is added when the monitor has failed to connect to this node, and ? when the monitor didn’t connect to the node yet.

  • Current State

    The current FSM state as reported to the monitor by the pg_autoctl process running on the Postgres node.

  • Assigned State

    The assigned FSM state on the monitor. When the assigned state is not the same as the reported start, then the pg_autoctl process running on the Postgres node might have not retrieved the assigned state yet, or might still be implementing the FSM transition from the current state to the assigned state.

Examples

$ pg_autoctl show state
 Name |  Node |      Host:Port |       TLI: LSN |   Connection |       Current State |      Assigned State
------+-------+----------------+----------------+--------------+---------------------+--------------------
node1 |     1 | localhost:5501 |   1: 0/4000678 |   read-write |             primary |             primary
node2 |     2 | localhost:5502 |   1: 0/4000678 |    read-only |           secondary |           secondary
node3 |     3 | localhost:5503 |   1: 0/4000678 |    read-only |           secondary |           secondary

$ pg_autoctl show state --local
 Name |  Node |      Host:Port |       TLI: LSN |   Connection |       Current State |      Assigned State
------+-------+----------------+----------------+--------------+---------------------+--------------------
node1 |     1 | localhost:5501 |   1: 0/4000678 | read-write ? |             primary |             primary

$ pg_autoctl show state --json
[
    {
        "health": 1,
        "node_id": 1,
        "group_id": 0,
        "nodehost": "localhost",
        "nodename": "node1",
        "nodeport": 5501,
        "reported_lsn": "0/4000678",
        "reported_tli": 1,
        "formation_kind": "pgsql",
        "candidate_priority": 50,
        "replication_quorum": true,
        "current_group_state": "primary",
        "assigned_group_state": "primary"
    },
    {
        "health": 1,
        "node_id": 2,
        "group_id": 0,
        "nodehost": "localhost",
        "nodename": "node2",
        "nodeport": 5502,
        "reported_lsn": "0/4000678",
        "reported_tli": 1,
        "formation_kind": "pgsql",
        "candidate_priority": 50,
        "replication_quorum": true,
        "current_group_state": "secondary",
        "assigned_group_state": "secondary"
    },
    {
        "health": 1,
        "node_id": 3,
        "group_id": 0,
        "nodehost": "localhost",
        "nodename": "node3",
        "nodeport": 5503,
        "reported_lsn": "0/4000678",
        "reported_tli": 1,
        "formation_kind": "pgsql",
        "candidate_priority": 50,
        "replication_quorum": true,
        "current_group_state": "secondary",
        "assigned_group_state": "secondary"
    }
]