Usage

Galera Cluster for MySQL or Mariadb is a true Multimaster Cluster based on synchronous replication. Galera Cluster is an easy-to-use, high-availability solution, which provides high system uptime, no data loss and scalability for future growth.

Sample pillars

Galera cluster master node

galera:
  version:
    mysql: 5.6
    galera: 3
  engine: mysql or mariadb
  master:
    enabled: true
    name: openstack
    bind:
      address: 192.168.0.1
      port: 3306
    members:
    - host: 192.168.0.1
      port: 4567
    - host: 192.168.0.2
      port: 4567
    admin:
      user: root
      password: pass
    database:
      name:
        encoding: 'utf8'
        users:
        - name: 'username'
          password: 'password'
          host: 'localhost'
          rights: 'all privileges'
          database: '*.*'

Galera cluster slave node

galera:
  slave:
    enabled: true
    name: openstack
    bind:
      address: 192.168.0.2
      port: 3306
    members:
    - host: 192.168.0.1
      port: 4567
    - host: 192.168.0.2
      port: 4567
    admin:
      user: root
      password: pass

Enable TLS support:

galera:
   slave or master:
     ssl:
      enabled: True
      ciphers:
        DHE-RSA-AES128-SHA:
          enabled: True
        DHE-RSA-AES256-SHA:
          enabled: True
        EDH-RSA-DES-CBC3-SHA:
          name: EDH-RSA-DES-CBC3-SHA
          enabled: True
        AES128-SHA:AES256-SHA:
          name: AES128-SHA:AES256-SHA
          enabled: True
        DES-CBC3-SHA:
          enabled: True
      # path
      cert_file: /etc/mysql/ssl/cert.pem
      key_file: /etc/mysql/ssl/key.pem
      ca_file: /etc/mysql/ssl/ca.pem

      # content (not required if files already exists)
      key: << body of key >>
      cert: << body of cert >>
      cacert_chain: << body of ca certs chain >>

Additional mysql users:

mysql:
  server:
    users:
      - name: clustercheck
        password: clustercheck
        database: '*.*'
        grants: PROCESS
      - name: inspector
        host: 127.0.0.1
        password: password
        databases:
          mydb:
            - database: mydb
            - table: mytable
            - grant_option: True
            - grants:
              - all privileges

Additional mysql SSL grants:

mysql:
  server:
    users:
      - name: clustercheck
        password: clustercheck
        database: '*.*'
        grants: PROCESS
        ssl_option:
          - SSL: True
          - X509: True
          - SUBJECT: <subject>
          - ISSUER: <issuer>
          - CIPHER: <cipher>

Additional check params:

galera:
  clustercheck:
    - enabled: True
    - user: clustercheck
    - password: clustercheck
    - available_when_donor: 0
    - available_when_readonly: 1
    - port 9200

Configurable soft parameters

• galera_innodb_buffer_pool_size

  Default is 3138M

• galera_max_connections

  Default is 20000

• galera_innodb_read_io_threads

  Default is 8

• galera_innodb_write_io_threads

  Default is 8

• galera_wsrep_slave_threads

  Default is 8

• galera_xtrabackup_parallel

  Default is 4

• galera_error_log_enabled

  Default is true

• galera_error_log_path

  Default is /var/log/mysql/error.log

Usage:

_param:
  galera_innodb_buffer_pool_size: 1024M
  galera_max_connections: 200
  galera_innodb_read_io_threads: 16
  galera_innodb_write_io_threads: 16
  galera_wsrep_slave_threads: 8
  galera_xtrabackup_parallel: 2
  galera_error_log_enabled: true
  galera_error_log_path: /var/log/mysql/error.log

Usage

MySQL/Mariadb Galera check sripts

mysql> SHOW STATUS LIKE 'wsrep%';

mysql> SHOW STATUS LIKE 'wsrep_cluster_size' ;"

Galera monitoring command, performed from extra server

garbd -a gcomm://ipaddrofone:4567 -g my_wsrep_cluster -l /tmp/1.out -d

1. salt-call state.sls mysql

2. Comment everything starting wsrep* (wsrep_provider, wsrep_cluster, wsrep_sst)

3. service mysql start

4. run on each node mysql_secure_install and filling root password.

   Enter current password for root (enter for none):
   OK, successfully used password, moving on...
   
   Setting the root password ensures that nobody can log into the MySQL
   root user without the proper authorisation.
   
   Set root password? [Y/n] y
   New password:
   Re-enter new password:
   Password updated successfully!
   Reloading privilege tables..
    ... Success!
   
   By default, a MySQL installation has an anonymous user, allowing anyone
   to log into MySQL without having to have a user account created for
   them.  This is intended only for testing, and to make the installation
   go a bit smoother.  You should remove them before moving into a
   production environment.
   
   Remove anonymous users? [Y/n] y
    ... Success!
   
   Normally, root should only be allowed to connect from 'localhost'.  This
   ensures that someone cannot guess at the root password from the network.
   
   Disallow root login remotely? [Y/n] n
    ... skipping.
   
   By default, MySQL comes with a database named 'test' that anyone can
   access.  This is also intended only for testing, and should be removed
   before moving into a production environment.
   
   Remove test database and access to it? [Y/n] y
    - Dropping test database...
    ... Success!
    - Removing privileges on test database...
    ... Success!
   
   Reloading the privilege tables will ensure that all changes made so far
   will take effect immediately.
   
   Reload privilege tables now? [Y/n] y
    ... Success!
   
   Cleaning up...

5. service mysql stop

6. uncomment all wsrep* lines except first server, where leave only in my.cnf wsrep_cluster_address='gcomm://';

7. start first node

8. Start third node which is connected to first one

9. Start second node which is connected to third one

10. After starting cluster, it must be change cluster address at first starting node without restart database and change config my.cnf.

    mysql> SET GLOBAL wsrep_cluster_address='gcomm://10.0.0.2';

Read more

• https://github.com/CaptTofu/ansible-galera
• http://www.sebastien-han.fr/blog/2012/04/15/active-passive-failover-cluster-on-a-mysql-galera-cluster-with-haproxy-lsb-agent/
• http://opentodo.net/2012/12/mysql-multi-master-replication-with-galera/
• http://www.codership.com/wiki/doku.php
• http://www.sebastien-han.fr/blog/2012/04/01/mysql-multi-master-replication-with-galera/

Documentation and bugs

• http://salt-formulas.readthedocs.io/

  Learn how to install and update salt-formulas

• https://github.com/salt-formulas/salt-formula-galera/issues In the unfortunate event that bugs are discovered, report the issue to the appropriate issue tracker. Use the Github issue tracker for a specific salt formula

• https://launchpad.net/salt-formulas

  For feature requests, bug reports, or blueprints affecting the entire ecosystem, use the Launchpad salt-formulas project

• https://launchpad.net/~salt-formulas-users

  Join the salt-formulas-users team and subscribe to mailing list if required

• https://github.com/salt-formulas/salt-formula-galera

  Develop the salt-formulas projects in the master branch and then submit pull requests against a specific formula

• #salt-formulas @ irc.freenode.net

  Use this IRC channel in case of any questions or feedback which is always welcome