PG_AUTOCTL_CREATE_COORDINATOR(1)

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version 2.1 · 2 versions
, in fedora 43, fedora 44

💖 PG_AUTOCTL CREATE COORDINATOR — bestie edition 💖

okay so real quick, this whole thing lives in the pg_auto_failover manual, and it's about one very specific little guy: pg_autoctl create coordinator. she's the boss of the Citus formation and she's about to tell you exactly how to summon her ✨

✨ NAME ✨

pg_autoctl create coordinator — pg_autoctl create coordinator

pg_autoctl create coordinator — Initialize a pg_auto_failover coordinator node

🦋 SYNOPSIS 🦋

The command pg_autoctl create coordinator initializes a pg_auto_failover Coordinator node for a Citus formation. The coordinator is special in a Citus formation: that's where the client application connects to either to manage the formation and the sharding of the tables, or for its normal SQL traffic.

The coordinator also has to register every worker in the formation.

  usage: pg_autoctl create coordinator

    --pgctl           path to pg_ctl
    --pgdata          path to data directory
    --pghost          PostgreSQL's hostname
    --pgport          PostgreSQL's port number
    --hostname        hostname by which postgres is reachable
    --listen          PostgreSQL's listen_addresses
    --username        PostgreSQL's username
    --dbname          PostgreSQL's database name
    --name            pg_auto_failover node name
    --formation       pg_auto_failover formation
    --monitor         pg_auto_failover Monitor Postgres URL
    --auth            authentication method for connections from monitor
    --skip-pg-hba     skip editing pg_hba.conf rules
    --citus-secondary when used, this worker node is a citus secondary
    --citus-cluster   name of the Citus Cluster for read-replicas
    --ssl-self-signed setup network encryption using self signed certificates (does NOT protect against MITM)
    --ssl-mode        use that sslmode in connection strings
    --ssl-ca-file     set the Postgres ssl_ca_file to that file path
    --ssl-crl-file    set the Postgres ssl_crl_file to that file path
    --no-ssl          don't enable network encryption (NOT recommended, prefer --ssl-self-signed)
    --server-key      set the Postgres ssl_key_file to that file path
    --server-cert     set the Postgres ssl_cert_file to that file path

🌸 DESCRIPTION 🌸

So this command does literally everything pg_autoctl create postgres does (same energy, same vibes), and then it does these three extra little side quests:

  1. adds shared_preload_libraries = citus to the local PostgreSQL instance configuration.
  2. enables the whole local area network to connect to the coordinator, by adding an entry for e.g. 192.168.1.0/24 in the PostgreSQL HBA configuration.
  3. creates the extension citus in the target database.
IMPORTANT, bestie, pls read this one 🙈: The default --dbname is the same as the current system user name, which in many case is going to be postgres. Please make sure to use the --dbname option with the actual database that you're going to use with your application. Citus does not support multiple databases, you have to use the database where Citus is created. When using Citus, that is essential to the well behaving of worker failover.

💅 OPTIONS 💅

See the manual page for pg_autoctl create postgres for the common options. This section now lists the options that are specific to pg_autoctl create coordinator:

  • --citus-secondary — Use this option to create a coordinator dedicated to a Citus Secondary cluster.

See Citus Secondaries and read-replica for more information.

  • --citus-cluster — Use this option to name the Citus Secondary cluster that this coordinator node belongs to. Use the same cluster name again for the worker nodes that are part of this cluster.

See Citus Secondaries and read-replica for more information.

👑 AUTHOR 👑

Microsoft

Copyright (c) Microsoft Corporation. All rights reserved.

okay that's the whole page, you ate that 🫶 this was version 2.1, dated Jan 18, 2025 — go forth and create your coordinator, no cap 💜✨

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