ha/citus

13-node Citus distributed PostgreSQL cluster, 1 coordinator + 5 worker groups with HA

The ha/citus template deploys a Citus distributed PostgreSQL cluster. It has 1 infrastructure node, 1 coordinator group, and 5 worker groups. The coordinator and worker groups contain 12 Citus nodes in total. The cluster distributes data into shards and supports horizontal scaling.

Overview

Config Name: ha/citus
Node Count: 13 nodes (1 infra + 1 coordinator×2 + 5 workers×2)
Description: Citus distributed PostgreSQL HA cluster
OS Distro: el8, el9, el10, d12, d13, u22, u24, u26
OS Arch: x86_64
Related: meta, ha/trio

Usage:

./configure -c ha/citus

Note: 13-node template, modify IP addresses after generation

Content

Source: pigsty/conf/ha/citus.yml

---
#==============================================================#
# File      :   citus.yml
# Desc      :   13-node Citus (6-group Distributive) Config Template
# Ctime     :   2020-05-22
# Mtime     :   2025-01-20
# Docs      :   https://pigsty.io/docs/conf/citus
# License   :   Apache-2.0 @ https://pigsty.io/docs/about/license/
# Copyright :   2018-2026  Ruohang Feng / Vonng ([email protected])
#==============================================================#

# This is the config template for Citus Distributive Cluster
# tutorial: https://pigsty.io/docs/pgsql/kernel/citus
# we will use the local repo for cluster bootstrapping
#
# Topology:
#   - pg-citus0: coordinator (10.10.10.10)         VIP: 10.10.10.19
#   - pg-citus1: worker group 1 (10.10.10.21, 22)  VIP: 10.10.10.29
#   - pg-citus2: worker group 2 (10.10.10.31, 32)  VIP: 10.10.10.39
#   - pg-citus3: worker group 3 (10.10.10.41, 42)  VIP: 10.10.10.49
#   - pg-citus4: worker group 4 (10.10.10.51, 52)  VIP: 10.10.10.59
#   - pg-citus5: worker group 5 (10.10.10.61, 62)  VIP: 10.10.10.69
#   - pg-citus6: worker group 6 (10.10.10.71, 72)  VIP: 10.10.10.79
#
# Usage:
#   curl https://repo.pigsty.io/get | bash
#   ./configure -c citus
#   ./deploy.yml

all:
  children:
    infra: { hosts: { 10.10.10.10: { infra_seq: 1 }}}
    etcd:  { hosts: { 10.10.10.10: { etcd_seq: 1  }}, vars: { etcd_cluster: etcd }}
    pg-meta:
      hosts: { 10.10.10.10: { pg_seq: 1, pg_role: primary } }
      vars:
        pg_cluster: pg-meta
        pg_users:
          - { name: dbuser_meta ,password: DBUser.Meta   ,pgbouncer: true ,roles: [dbrole_admin   ] ,comment: pigsty admin user }
        pg_databases:
          - name: meta
            baseline: cmdb.sql
            comment: "pigsty meta database"
            schemas: [pigsty]
            extensions: [ postgis, vector ]
        pg_crontab: [ '00 01 * * * /pg/bin/pg-backup full' ] # make a full backup every day 1am

    #----------------------------------------------------------#
    # pg-citus: 6 cluster groups, 12 nodes total
    #----------------------------------------------------------#
    pg-citus:
      hosts:

        # coordinator (group 0) on infra node
        10.10.10.21: { pg_group: 0, pg_cluster: pg-citus1 ,pg_vip_address: 10.10.10.29/24 ,pg_seq: 1, pg_role: primary }
        10.10.10.22: { pg_group: 0, pg_cluster: pg-citus1 ,pg_vip_address: 10.10.10.29/24 ,pg_seq: 2, pg_role: replica }

        # worker group 2
        10.10.10.31: { pg_group: 1, pg_cluster: pg-citus2 ,pg_vip_address: 10.10.10.39/24 ,pg_seq: 1, pg_role: primary }
        10.10.10.32: { pg_group: 1, pg_cluster: pg-citus2 ,pg_vip_address: 10.10.10.39/24 ,pg_seq: 2, pg_role: replica }

        # worker group 3
        10.10.10.41: { pg_group: 2, pg_cluster: pg-citus3 ,pg_vip_address: 10.10.10.49/24 ,pg_seq: 1, pg_role: primary }
        10.10.10.42: { pg_group: 2, pg_cluster: pg-citus3 ,pg_vip_address: 10.10.10.49/24 ,pg_seq: 2, pg_role: replica }

        # worker group 4
        10.10.10.51: { pg_group: 3, pg_cluster: pg-citus4 ,pg_vip_address: 10.10.10.59/24 ,pg_seq: 1, pg_role: primary }
        10.10.10.52: { pg_group: 3, pg_cluster: pg-citus4 ,pg_vip_address: 10.10.10.59/24 ,pg_seq: 2, pg_role: replica }

        # worker group 5
        10.10.10.61: { pg_group: 4, pg_cluster: pg-citus5 ,pg_vip_address: 10.10.10.69/24 ,pg_seq: 1, pg_role: primary }
        10.10.10.62: { pg_group: 4, pg_cluster: pg-citus5 ,pg_vip_address: 10.10.10.69/24 ,pg_seq: 2, pg_role: replica }

        # worker group 6
        10.10.10.71: { pg_group: 5, pg_cluster: pg-citus6 ,pg_vip_address: 10.10.10.79/24 ,pg_seq: 1, pg_role: primary }
        10.10.10.72: { pg_group: 5, pg_cluster: pg-citus6 ,pg_vip_address: 10.10.10.79/24 ,pg_seq: 2, pg_role: replica }

      vars:
        pg_mode: citus                            # pgsql cluster mode: citus
        pg_shard: pg-citus                        # citus shard name: pg-citus
        pg_primary_db: citus                      # primary database used by citus
        pg_dbsu_password: DBUser.Postgres         # enable dbsu password access for citus
        pg_extensions: [ citus, postgis, pgvector, topn, pg_cron, hll ]
        pg_libs: 'citus, pg_cron, pg_stat_statements'
        pg_users: [{ name: dbuser_citus ,password: DBUser.Citus ,pgbouncer: true ,roles: [ dbrole_admin ] }]
        pg_databases: [{ name: citus ,owner: dbuser_citus ,extensions: [ citus, vector, topn, pg_cron, hll ] }]
        pg_parameters:
          cron.database_name: citus
          citus.node_conninfo: 'sslrootcert=/pg/cert/ca.crt sslmode=verify-full'
        pg_hba_rules:
          - { user: 'all' ,db: all  ,addr: 127.0.0.1/32  ,auth: ssl ,title: 'all user ssl access from localhost' }
          - { user: 'all' ,db: all  ,addr: intra         ,auth: ssl ,title: 'all user ssl access from intranet'  }
        pg_vip_enabled: true
        pg_crontab: [ '00 01 * * * /pg/bin/pg-backup full' ] # make a full backup every day 1am

  vars:
    #----------------------------------------------#
    # INFRA : https://pigsty.io/docs/infra/param
    #----------------------------------------------#
    version: v4.5.0
    admin_ip: 10.10.10.10
    region: default
    infra_portal:
      home : { domain: i.pigsty }

    #----------------------------------------------#
    # NODE : https://pigsty.io/docs/node/param
    #----------------------------------------------#
    nodename_overwrite: true
    node_repo_modules: node,infra,pgsql
    node_tune: oltp

    #----------------------------------------------#
    # PGSQL : https://pigsty.io/docs/pgsql/param
    #----------------------------------------------#
    pg_version: 18  # PostgreSQL 14-18
    pg_conf: oltp.yml
    pg_packages: [ pgsql-main, pgsql-common ]

    #----------------------------------------------#
    # PASSWORD : https://pigsty.io/docs/setup/security/
    #----------------------------------------------#
    grafana_admin_password: pigsty
    grafana_view_password: DBUser.Viewer
    pg_admin_password: DBUser.DBA
    pg_monitor_password: DBUser.Monitor
    pg_replication_password: DBUser.Replicator
    patroni_password: Patroni.API
    haproxy_admin_password: pigsty
    minio_secret_key: S3User.MinIO
    etcd_root_password: Etcd.Root
...

Topology

Cluster	Nodes	IP Addresses	VIP	Role
pg-meta	1	10.10.10.10	-	Infra + CMDB
pg-citus1	2	10.10.10.21, 22	10.10.10.29	Coordinator (group 0)
pg-citus2	2	10.10.10.31, 32	10.10.10.39	Worker (group 1)
pg-citus3	2	10.10.10.41, 42	10.10.10.49	Worker (group 2)
pg-citus4	2	10.10.10.51, 52	10.10.10.59	Worker (group 3)
pg-citus5	2	10.10.10.61, 62	10.10.10.69	Worker (group 4)
pg-citus6	2	10.10.10.71, 72	10.10.10.79	Worker (group 5)

Architecture:

pg-meta: Infra node running Grafana, VictoriaMetrics, etcd, plus a standalone CMDB
pg-citus1: Coordinator group 0 with 1 primary and 1 replica. It receives queries and routes them to workers.
pg-citus2~6: Worker groups 1~5 store sharded data. Patroni manages 1 primary and 1 replica in each group.
VIP: Each group has L2 VIP managed by vip-manager for transparent failover

Explanation

Use ha/citus to deploy a production Citus cluster that can scale across multiple worker groups.

Key Features:

Horizontal Scaling: 5 worker groups for linear storage/compute scaling
High Availability: Each group with 1 primary + 1 replica, auto-failover
L2 VIP: Virtual IP per group, transparent failover to clients
SSL Encryption: Inter-node communication uses SSL certificates
Transparent Sharding: Data auto-distributed across workers

Pre-installed Extensions:

pg_extensions: [ citus, postgis, pgvector, topn, pg_cron, hll ]
pg_libs: 'citus, pg_cron, pg_stat_statements'

Security:

pg_dbsu_password enabled for Citus inter-node communication
HBA rules require SSL authentication
Inter-node uses certificate verification: sslmode=verify-full

Deployment

# 1. Download Pigsty
curl -fsSL https://repo.pigsty.io/get | bash; cd ~/pigsty

# 2. Use ha/citus template
./configure -c ha/citus

# 3. Modify IPs and passwords
vi pigsty.yml

# 4. Deploy entire cluster
./deploy.yml

Verify after deployment:

-- Connect to coordinator
psql -h 10.10.10.29 -U dbuser_citus -d citus

-- Check worker nodes
SELECT * FROM citus_get_active_worker_nodes();

-- Check shard distribution
SELECT * FROM citus_shards;

Examples

Create Distributed Table:

-- Create table
CREATE TABLE events (
    tenant_id INT,
    event_id BIGSERIAL,
    event_time TIMESTAMPTZ DEFAULT now(),
    payload JSONB,
    PRIMARY KEY (tenant_id, event_id)
);

-- Distribute by tenant_id
SELECT create_distributed_table('events', 'tenant_id');

-- Insert (auto-routed to correct shard)
INSERT INTO events (tenant_id, payload)
VALUES (1, '{"type": "click"}');

-- Query (parallel execution)
SELECT tenant_id, count(*)
FROM events
GROUP BY tenant_id;

Create Reference Table (replicated to all nodes):

CREATE TABLE tenants (
    tenant_id INT PRIMARY KEY,
    name TEXT
);

SELECT create_reference_table('tenants');

Use Cases

Multi-tenant SaaS: Shard by tenant_id for data isolation and parallel queries
Real-time Analytics: Large-scale event data aggregation
Timeseries Data: Combine with TimescaleDB for massive timeseries
Horizontal Scaling: When single-table data exceeds single-node capacity

Notes

PostgreSQL Version: Citus supports PG 14~18, this template defaults to PG18
Distribution Column: Select this column for the workload, typically tenant_id or timestamp. This choice is critical for performance.
Cross-shard Limits: Foreign keys must include the distribution column. Some DDL operations also have restrictions.
Network: pg_vip_interface defaults to auto. For unusual network environments, explicitly select an interface.
Architecture: Citus extension does not support ARM64