galera_maxscale

Table of Contents

1. Description
2. Setup - The basics of getting started with galera_maxscale
   • What galera_maxscale affects
   • Setup requirements
   • Beginning with galera_maxscale
3. Usage - Configuration options and additional functionality
4. Reference - An under-the-hood peek at what the module is doing and how
5. Limitations - OS compatibility, etc.
6. Development - Guide for contributing to the module

Description

This module sets up and bootstrap Galera cluster and MaxScale Proxy. The subsequent management of the Galera cluster is demanded to the script galera_wizard.yp. MaxScale Proxy will set up on 2 nodes with Keepalived

Setup

Beginning with galera_maxscale

To setup a galera cluster:

class { 'galera':
  root_password    => $root_password,
  sst_password     => $sst_password,
  monitor_password => $monitor_password,
  galera_hosts     => $galera_hosts,
  trusted_networks => $trusted_networks,
  lv_size          => $lv_size;
}

To setup MaxScale:

class { 'galera::maxscale::maxscale':
  trusted_networks => $trusted_networks,
  maxscale_hosts   => $maxscale_hosts,
  maxscale_vip     => $maxscale_vip,
  galera_hosts     => $galera_hosts;
}

Once you have run puppet on every node, you can manage or check the cluster using the script:

[root@test-galera01 ~]# galera_wizard.py -h
usage: galera_wizard.py [-h] [-cg] [-dr] [-je] [-be] [-jn] [-bn]

Use this script to bootstrap, join nodes within a Galera Cluster
----------------------------------------------------------------
  Avoid joining more than one node at once!

optional arguments:
  -h, --help                 show this help message and exit
  -cg, --check-galera        check if all nodes are healthy
  -dr, --dry-run             show SQL statements to run on this cluster
  -je, --join-existing       join existing Cluster
  -be, --bootstrap-existing  bootstrap existing Cluster
  -jn, --join-new            join existing Cluster
  -bn, --bootstrap-new       bootstrap new Cluster
  -f, --force                force bootstrap new or join new Cluster

Author: Massimiliano Adamo <maxadamo@gmail.com>

Usage

The module will fail with an even number of nodes, and with a number of nodes lower than 3.

To setup a Galera Cluster (and optionally a MaxScale cluster with Keepalived) we need a hash. If you use hiera it will be like this:

galera_hosts:
  test-galera01.example.net:
    ipv4: '192.168.0.83'
    ipv6: '2001:123:4::6b'
  test-galera02.example.net:
    ipv4: '192.168.0.84'
    ipv6: '2001:123:4::6c'
  test-galera03.example.net:
    ipv4: '192.168.0.85'
    ipv6: '2001:123:4::6d'
maxscale_hosts:
  test-maxscale01.example.net:
    ipv4: '192.168.0.86'
    ipv6: '2001:123:4::6e'
  test-maxscale02.example.net:
    ipv4: '192.168.0.87'
    ipv6: '2001:123:4::6f'
maxscale_vip:
  test-maxscale.example.net:
    ipv4: '192.168.0.88'
    ipv4_subnet: '22'
    ipv6: '2001:123:4::70'

If you don't use ipv6, just skip the ipv6 keys as following:

galera_hosts:
  test-galera01.example.net:
    ipv4: '192.168.0.83'
  test-galera02.example.net:
    ipv4: '192.168.0.84'
  test-galera03.example.net:
... and so on ..

you need an array of trusted networks/hosts (a list of ipv4/ipv6 networks/hosts allowed to connect to Galera socket):

trusted_networks:
  - 192.168.0.1/24
  - 2001:123:4::70/64
  - 192.168.1.44
... and so on ...

To setup a galera cluster:

class { 'galera':
  root_password    => $root_password,
  sst_password     => $sst_password,
  monitor_password => $monitor_password,
  galera_hosts     => $galera_hosts,
  trusted_networks => $trusted_networks,
  lv_size          => $lv_size;
}

To setup MaxScale:

class { 'galera::maxscale::maxscale':
  trusted_networks => $trusted_networks,
  maxscale_hosts   => $maxscale_hosts,
  maxscale_vip     => $maxscale_vip,
  galera_hosts     => $galera_hosts;
}

Reference

Limitations

• not fully tested on ipv4 only
• keepalived is missing configuration for ipv6
• init.pp is missing the full list of parameters
• not tested yet on Ubuntu

Development

Feel free to make pull requests and/or open issues on my GitHub Repository

Release Notes/Contributors/Etc. Optional