mariadb 可以看做是常见的数据库,负责连接应用(web, API 等)
单纯的 mariadb 无法实现多个主服务器数据同步
多台数据库中数据同步由 wsrep 接口实现
最终目标,实现多个 MySQL 同时读写
wsrep API 是一种数据库插件接口,比较类似一种应用程序,主要针对写复制
该程序主要用于定义应用程序如何调用复制库实现回写
wsrep API 由支持改库的应用程序动态装载
wsrep API 描述下面复制模型,一个应用程序,如数据库当前的一个对象,当前被客户端修改,对象改变导致事务产生一系列的原子性改变, 在集群中所有的节点都具备相同的对象,并由同步复制应用都各自节点,按照相同的顺序产生相同变化从而实现数据同步
一个 UUID 作为对象标识及经历改变的序号,序号会发生连续的改变
GTID 允许比较应用程序状态,建立对象改变的顺序,决定对象的变化是否需要更新 GTID
node-1:192.168.200.4 mariadb:10.1.30 galera:25.3.22
node-2:192.168.200.5 mariadb:10.1.30 galera:25.3.22
[root@node-1 ~]# yum install MariaDB-server galera
[root@node-2 ~]# yum install MariaDB-server galera
[root@node-1 ~]# vi /etc/my.cnf
[mysqld]
max_connect_errors=1000
[root@node-1 ~]# vi /etc/my.cnf.d/server.cnf
[galera]
wsrep_on=ON
wsrep_provider=/usr/lib64/galera/libgalera_smm.so
wsrep_cluster_address=gcomm://
binlog_format=row
default_storage_engine=InnoDB
innodb_autoinc_lock_mode=2
bind-address=0.0.0.0
wsrep_cluster_name="MariaDB_Cluster"
wsrep_node_address="192.168.200.4"
wsrep_sst_method=rsyn
[root@node-2 ~]# vi /etc/my.cnf
[mysqld]
max_connect_errors=1000
[root@node-2 ~]# vi /etc/my.cnf.d/server.cnf
[galera]
# Mandatory settings
wsrep_on=ON
wsrep_provider=/usr/lib64/galera/libgalera_smm.so
wsrep_cluster_address="gcomm://192.168.200.4,192.168.200.5"
binlog_format=row
default_storage_engine=InnoDB
innodb_autoinc_lock_mode=2
bind-address=0.0.0.0
wsrep_node_address="192.168.200.5"
wsrep_cluster_name="MariaDB_Cluster"
wsrep_sst_method=rsync
[root@node-1 ~]# /bin/galera_new_cluster
[root@node-2 ~]# systemctl start mariadb
[root@node-1 ~]# mysql -uroot -p
MariaDB [(none)]> show status like "wsrep_%";
+------------------------------+-----------------------------------------------+
| Variable_name | Value |
+------------------------------+-----------------------------------------------+
| wsrep_apply_oooe | 0.000000 |
| wsrep_apply_oool | 0.000000 |
| wsrep_apply_window | 0.000000 |
| wsrep_causal_reads | 0 |
| wsrep_cert_deps_distance | 0.000000 |
| wsrep_cert_index_size | 0 |
| wsrep_cert_interval | 0.000000 |
| wsrep_cluster_conf_id | 2 |
| wsrep_cluster_size | 2 |
| wsrep_cluster_state_uuid | 3fa7ddbb-6839-11e9-a6f5-2b4eac1b9da2 |
| wsrep_cluster_status | Primary |
| wsrep_commit_oooe | 0.000000 |
| wsrep_commit_oool | 0.000000 |
| wsrep_commit_window | 0.000000 |
| wsrep_connected | ON |
| wsrep_desync_count | 0 |
| wsrep_evs_delayed | |
| wsrep_evs_evict_list | |
| wsrep_evs_repl_latency | 0.000522839/0.0016527/0.00400798/0.00117158/6 |
| wsrep_evs_state | OPERATIONAL |
| wsrep_flow_control_paused | 0.000000 |
| wsrep_flow_control_paused_ns | 0 |
| wsrep_flow_control_recv | 0 |
| wsrep_flow_control_sent | 0 |
| wsrep_gcomm_uuid | 3fa68225-6839-11e9-9abe-478e95b9264a |
| wsrep_incoming_addresses | 192.168.200.4:3306,192.168.200.5:3306 |
| wsrep_last_committed | 0 |
| wsrep_local_bf_aborts | 0 |
| wsrep_local_cached_downto | 18446744073709551615 |
| wsrep_local_cert_failures | 0 |
| wsrep_local_commits | 0 |
| wsrep_local_index | 0 |
| wsrep_local_recv_queue | 0 |
| wsrep_local_recv_queue_avg | 0.166667 |
| wsrep_local_recv_queue_max | 2 |
| wsrep_local_recv_queue_min | 0 |
| wsrep_local_replays | 0 |
| wsrep_local_send_queue | 0 |
| wsrep_local_send_queue_avg | 0.000000 |
| wsrep_local_send_queue_max | 1 |
| wsrep_local_send_queue_min | 0 |
| wsrep_local_state | 4 |
| wsrep_local_state_comment | Synced |
| wsrep_local_state_uuid | 3fa7ddbb-6839-11e9-a6f5-2b4eac1b9da2 |
| wsrep_protocol_version | 7 |
| wsrep_provider_name | Galera |
| wsrep_provider_vendor | Codership Oy |
| wsrep_provider_version | 25.3.22(r3764) |
| wsrep_ready | ON |
| wsrep_received | 6 |
| wsrep_received_bytes | 414 |
| wsrep_repl_data_bytes | 0 |
| wsrep_repl_keys | 0 |
| wsrep_repl_keys_bytes | 0 |
| wsrep_repl_other_bytes | 0 |
| wsrep_replicated | 0 |
| wsrep_replicated_bytes | 0 |
| wsrep_thread_count | 2 |
+------------------------------+-----------------------------------------------+
58 rows in set (0.00 sec)
#如果 "wsrep_local_state_comment" is "Synced" 则表明集群创建成功。
#在node-1创建数据库
[root@node-1 ~]# mysql -uroot -p
MariaDB [(none)]> create database galera_test;
Query OK, 1 row affected (0.06 sec)
MariaDB [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| galera_test |
| information_schema |
| mysql |
| performance_schema |
| test |
+--------------------+
5 rows in set (0.00 sec)
#在node-2上查询
[root@node-2 ~]# mysql -uroot -p
MariaDB [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| galera_test |
| information_schema |
| mysql |
| performance_schema |
| test |
+--------------------+
5 rows in set (0.00 sec)
#可以查询到galera_test数据库,说明数据库同步没问题。
转载于:https://blog.51cto.com/9103824/2385079