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.
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
galera_innodb_buffer_pool_sizeDefault is 3138M
galera_max_connectionsDefault is 20000
galera_innodb_read_io_threadsDefault is 8
galera_innodb_write_io_threadsDefault is 8
galera_wsrep_slave_threadsDefault is 8
galera_xtrabackup_parallelDefault is 4
galera_error_log_enabledDefault is true
galera_error_log_pathDefault 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_threadsgalera_innodb_write_io_threadsgalera_wsrep_slave_threadsUsage:
_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
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
salt-call state.sls mysql
Comment everything starting wsrep* (wsrep_provider, wsrep_cluster, wsrep_sst)
Service mysql start
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...
Service mysql stop
Uncomment all wsrep* lines except first server, where leave only in my.cnf wsrep_cluster_address=’gcomm://’;
Start first node
Start third node which is connected to first one
Start second node which is connected to third one
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';