# demo/mysql

> Native MySQL 8.4 pilot template with a standalone instance and a three-node InnoDB Cluster

---

LLMS index: [llms.txt](/llms.txt)

---

`demo/mysql` is the four-node example for the native MySQL 8.4 LTS pilot module. It is distinct from [`conf/mysql.yml`](/docs/conf/mysql/), which provides MySQL protocol compatibility through the OpenHalo PostgreSQL kernel.


--------

## Overview

- Config Name: `demo/mysql`
- Node Count: 4
- `my-meta`: Standalone MySQL 8.4 instance
- `my-test`: Three-node, single-primary InnoDB Cluster with MySQL Router on every member
- Module Status: MYSQL PILOT; not included in the stable module count
- Platform Boundary: Supported declared x86_64 RPM/DEB platforms and EL9/EL10 aarch64. Oracle APT currently has no arm64 component, so preflight rejects Debian/Ubuntu ARM.

Replace every `CHANGE_ME` value in the template. Real deployment also requires explicit approval. Start with read-only preflight checks:

```bash
ansible-playbook -i conf/demo/mysql.yml mysql.yml -l my-meta --check
ansible-playbook -i conf/demo/mysql.yml mysql.yml -l my-test --check
```

After explicitly approving an active-inventory update, run `./configure -c demo/mysql`, then run both `node.yml` and `mysql.yml` with `--check` and real convergence against the same complete cluster scope. The three-node cluster does not accept a partial-member scope.


--------

## Content

Source: [`pigsty/conf/demo/mysql.yml`](https://github.com/pgsty/pigsty/blob/main/conf/demo/mysql.yml)

```yaml
---
#==============================================================#
# File      :   mysql.yml
# Desc      :   MySQL 8.4 LTS standalone and three-node HA template
# Ctime     :   2026-07-16
# Mtime     :   2026-07-19
# Docs      :   https://pigsty.io/docs/mysql
# License   :   Apache-2.0 @ https://pigsty.io/docs/about/license/
# Copyright :   2018-2026  Ruohang Feng / Vonng (rh@vonng.com)
#==============================================================#

# Canonical four-node MySQL platform example:
#   my-meta: one standalone member
#   my-test: three-member InnoDB Cluster in single-primary mode
#
# This file is a template, not the active deployment inventory. Replace every
# CHANGE_ME value and review the target addresses before configure or playbooks;
# MySQL preflight rejects any canonical CHANGE_ME credential left in place.
# Native Oracle 8.4 packages are admitted on x86_64 and EL9/EL10 aarch64. Oracle's
# APT repository currently has no arm64 component, so Ubuntu/Debian ARM is rejected.
#
# Read-only template preview (does not rewrite active pigsty.yml):
#   ansible-playbook -i conf/demo/mysql.yml mysql.yml -l my-meta --check
#   ansible-playbook -i conf/demo/mysql.yml mysql.yml -l my-test --check
# Each limit must include every declared member of the selected cluster group;
# partial HA member limits are rejected before any package or service change.
# After explicit approval to update active inventory, run ./configure -c demo/mysql,
# then repeat node.yml/mysql.yml --check with the same explicit limits.
# node.yml owns the shared trusted CA at /etc/pki/ca.crt; mysql.yml installs
# only MySQL/Router leaf certificates and requires node_ca to be complete.
#
# Real playbooks install/start services and require explicit approval.

all:
  children:
    infra:
      hosts:
        10.10.10.10: { infra_seq: 1 }

    my-meta:
      hosts:
        10.10.10.10: { mysql_seq: 1 }
      vars: { mysql_cluster: my-meta, node_cluster: my-meta }

    my-test:
      hosts:
        10.10.10.11: { mysql_seq: 1 }
        10.10.10.12: { mysql_seq: 2 }
        10.10.10.13: { mysql_seq: 3 }
      vars: { mysql_cluster: my-test, node_cluster: my-test }

  vars:
    version: v4.5.0
    admin_ip: 10.10.10.10
    region: default                    # default | china; china uses USTC for MySQL

    repo_enabled: false               # use signed upstream repositories directly
    node_repo_modules: node,infra,mysql
    # For a Pigsty local/offline repository, enable repo and cache the complete
    # atomic platform set before provisioning targets:
    # repo_enabled: true
    # repo_extra_packages: [mysql]

    nodename_overwrite: false
    node_tune: oltp

    mysql_root_password: CHANGE_ME_MYSQL_ROOT
    mysql_monitor_password: CHANGE_ME_MYSQL_MONITOR
    mysql_cluster_password: CHANGE_ME_MYSQL_CLUSTER
    # Fixed MySQL 8.4, auto-tuned memory, daily local backup, and exporter are defaults.

    # Pigsty infrastructure credentials; replace before deployment.
    grafana_admin_password: CHANGE_ME_GRAFANA_ADMIN
    grafana_view_password: CHANGE_ME_GRAFANA_VIEW
    haproxy_admin_password: CHANGE_ME_HAPROXY
...
```


--------

## Explanation

- MySQL server, client, Shell, Router, and XtraBackup are fixed to the 8.4 platform; this is not an arbitrary-version installer.
- The standalone instance uses `3306`. The three-node cluster also uses Group Replication on `33061`, with Router RW on `6446` and RO on `6447` on each member.
- A daily local full XtraBackup and `mysqld_exporter` are enabled by default. The current pilot does not provide continuous binlog archiving, PITR, or automatic recovery.
- `node.yml` installs the shared trust anchor at `/etc/pki/ca.crt`; the MySQL role only issues and installs leaf certificates.

See the [native MySQL pilot documentation](/docs/mysql/) for complete constraints and the confirmed removal workflow.