galera

This role configures Galera/MariaDB 5.5 cluster.

Requirements

All requirements are listed in metadata file.

Role Variables

The variables that can be passed to this role and a brief description about them are as follows.

# MariaDB root user password
galera_root_password: 1qa2ws3ed

# MariaDB debian-sys-maint user password
galera_maintenance_password: 1qa2ws3ed

# Galera cluster authorization credentials
galera_cluster_user: replicator
galera_cluster_password: 1qa2ws3ed

# Address MariaDB will listen on
galera_bind_address: 127.0.0.1

# Nodes with this parameter set to zero will be configured as standalone,
# i.e. wsrep_cluster_address=gcomm://
galera_bootstrap: 0

# Unique Galera cluster identifier
galera_cluster_name: mycluster

# Addresses of cluster nodes to connect to
galera_cluster_members: [10.0.0.1, 10.0.0.2]

# Setup apt repository sources or not
galera_setup_repository: yes

# Install packages or not
galera_install_packages: yes

# Install ClusterCheck or not
galera_install_clustercheck: yes

So you can deploy multiple cluster within single inventory grouped by galera_cluster_name and setup interconnection by galera_cluster_members variable.

Examples

Install Galera cluster with default settings.

- hosts: cluster_one
  vars:
    - galera_cluster_name: cluster_one
    - galera_cluster_members: [10.0.0.1, 10.0.0.2]
  roles:
    - role: galera
      become: yes

- hosts: cluster_two
  vars:
    - galera_cluster_name: cluster_two
    - galera_cluster_members: [10.0.1.1, 10.0.1.2]
  roles:
    - role: galera
      become: yes

Example inventory file:

[cluster_one]
10.0.0.1 galera_bootstrap=1
10.0.0.2

[cluster_two]
10.0.1.1 galera_bootstrap=1
10.0.1.2

Helpers

Variable shows current node state:

mysql -e "SHOW STATUS LIKE 'wsrep_local_state_comment';"

Variable shows if node is ready to accept queries:

mysql -e "SHOW STATUS LIKE 'wsrep_ready';"

Variable shows if the node is connected to the cluster:

mysql -e "SHOW STATUS LIKE 'wsrep_connected';"

Variable shows status of the cluster component:

mysql -e "SHOW STATUS LIKE 'wsrep_cluster_status';"

Dependencies

None

License

LGPL

Author Information

• Alexey Medvedchikov, 2GIS, LLC
• Sergey Antipov, 2GIS, LLC