Usage

Usage

Galera Cluster for MySQL 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
  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
    sst:
      user: sstuser
      password: sstpassword
    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
    sst:
      user: sstuser
      password: sstpassword

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

When the following parameters are set to 0, their defaults will be calculated automatically based on the number of CPU cores:

  • galera_innodb_read_io_threads

  • galera_innodb_write_io_threads

  • galera_wsrep_slave_threads

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 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';