====== MariaDB Galera Cluster ======

http://www.codership.com/wiki/doku.php?id=Galera%20Wiki
https://mariadb.com/kb/en/mariadb/getting-started-with-mariadb-galera-cluster/

===== Install =====

==== Adding the MariaDB YUM Repository ====
<code>
# vi /etc/yum.repos.d/MariaDB.repo
</code>

=== MariaDB 10.0 CentOS repository list ===
<code>
[mariadb]
name = MariaDB
baseurl = http://yum.mariadb.org/10.0/centos6-amd64
gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB
gpgcheck=1
</code>

=== MariaDB 5.5 CentOS repository list ===
<code>
[mariadb]
name = MariaDB
baseurl = http://yum.mariadb.org/5.5/centos6-amd64
gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB
gpgcheck=1
</code>

==== Installing MariaDB Galera Cluster with YUM ====
<code>
# yum install MariaDB-Galera-server MariaDB-client galera
</code>

==== Configure ====
https://mariadb.com/kb/en/mariadb/galera-cluster-system-variables/
http://galeracluster.com/documentation-webpages/performance.html
<code>
# vi /etc/my.cnf.d/server.cnf 
</code>

<code>
[galera]
# Mandatory settings
# 任意のクラスタ名、デフォルト「my_wsrep_cluster」
wsrep_cluster_name=DBCLUSTER
# ライブラリファイルをフルパスで指定
wsrep_provider='/usr/lib64/galera/libgalera_smm.so'
# 参加するクラスタ・ノードのIPを指定。
wsrep_cluster_address=gcomm://192.168.56.211,192.168.56.212,192.168.56.213
# 自分のIPアドレスを指定、デフォルトはeth0のIPアドレス
wsrep_node_address=192.168.56.211

# CPUコア数の2倍、書き込み接続数の1/4
wsrep_slave_threads=4
innodb_locks_unsafe_For_binlog=1

binlog_format=row
default_storage_engine=InnoDB
innodb_autoinc_lock_mode=2
bind-address=0.0.0.0
</code>

==== Start Services ====
初期ノード起動時は「bootstrap」を指定
<code>
[root@db01 ~]# /etc/init.d/mysql bootstrap
Bootstrapping the cluster.. Starting MySQL.. SUCCESS! 

[root@db02 ~]# /etc/init.d/mysql start
Starting MySQL.. SUCCESS! 

[root@db03 ~]# /etc/init.d/mysql start
Starting MySQL.. SUCCESS! 
</code>

==== Check statuses ====
<code>
# mysql -h db03

MariaDB [(none)]> show status like 'wsrep_%';

+----------------------------+--------------------------------------+
| Variable_name              | Value                                |
+----------------------------+--------------------------------------+
～省略～
| wsrep_local_state_comment  | Synced                               |
| wsrep_cert_index_size      | 0                                    |
| wsrep_causal_reads         | 0                                    |
| wsrep_incoming_addresses   | 192.168.56.213:3306,                 |
～省略～
+----------------------------+--------------------------------------+
40 rows in set (0.00 sec)
</code>