此时,组中只有一个成员,即服务器 s1,其中包含一些数据。现在是通过添加之前配置的另外两个服务器来扩展组的时候了。
为了添加第二个实例,即服务器 s2,首先为其创建配置文件。该配置与用于服务器 s1 的配置类似,除了 server_id
等方面。
[mysqld]
#
# Disable other storage engines
#
disabled_storage_engines="MyISAM,BLACKHOLE,FEDERATED,ARCHIVE,MEMORY"
#
# Replication configuration parameters
#
server_id=2
gtid_mode=ON
enforce_gtid_consistency=ON
#
# Group Replication configuration
#
plugin_load_add='group_replication.so'
group_replication_group_name="aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa"
group_replication_start_on_boot=off
group_replication_local_address= "s2:33061"
group_replication_group_seeds= "s1:33061,s2:33061,s3:33061"
group_replication_bootstrap_group= off
类似于服务器 s1 的过程,配置文件到位后,您将启动服务器。然后配置分布式恢复凭据,如下所示。这些命令与设置 s1 作为服务器时使用的命令相同,因为用户在组内是共享的。此成员需要在 第 20.2.1.3 节,“分布式恢复的用户凭据” 中配置相同的复制用户。如果您依赖分布式恢复在所有成员上配置用户,当 s2 连接到种子 s1 时,复制用户会被复制或克隆到 s1。如果您在 s1 上配置用户凭据时没有启用二进制日志记录,并且没有使用远程克隆操作进行状态传输,则必须在 s2 上创建复制用户。在这种情况下,连接到 s2 并发出以下命令
SET SQL_LOG_BIN=0;
CREATE USER rpl_user@'%' IDENTIFIED BY 'password';
GRANT REPLICATION SLAVE ON *.* TO rpl_user@'%';
GRANT CONNECTION_ADMIN ON *.* TO rpl_user@'%';
GRANT BACKUP_ADMIN ON *.* TO rpl_user@'%';
GRANT GROUP_REPLICATION_STREAM ON *.* TO rpl_user@'%';
FLUSH PRIVILEGES;
SET SQL_LOG_BIN=1;
如果您使用 CHANGE REPLICATION SOURCE TO
提供用户凭据,请在执行完该语句后执行以下语句
CHANGE REPLICATION SOURCE TO SOURCE_USER='rpl_user', SOURCE_PASSWORD='password' \
FOR CHANNEL 'group_replication_recovery';
如果您使用的是缓存 SHA-2 身份验证插件(默认插件),请参阅 第 20.6.3.1.1 节,“使用缓存 SHA-2 身份验证插件的复制用户”。
如有必要,安装组复制插件,请参阅 第 20.2.1.4 节,“启动组复制”。
启动组复制,s2 开始加入组的过程。
mysql> START GROUP_REPLICATION;
或者,如果您在 START GROUP_REPLICATION
语句中提供分布式恢复的用户凭据
mysql> START GROUP_REPLICATION USER='rpl_user', PASSWORD='password';
与之前在 s1 上执行的相同步骤不同,这里有一个区别,即您 不需要 引导组,因为组已经存在。换句话说,在 s2 上 group_replication_bootstrap_group
设置为 OFF
,并且您不会在启动组复制之前发出 SET GLOBAL group_replication_bootstrap_group=ON;
,因为组已经由服务器 s1 创建和引导。此时,服务器 s2 只需要添加到现有的组中。
当组复制成功启动并且服务器加入组时,它会检查 super_read_only
变量。通过在成员的配置文件中将 super_read_only
设置为 ON,您可以确保因任何原因启动组复制失败的服务器不接受事务。如果服务器应作为读写实例加入组,例如作为单主组中的主服务器或多主组中的成员,当 super_read_only
变量设置为 ON 时,它将在加入组后设置为 OFF。
再次检查 performance_schema.replication_group_members
表显示组中现在有两个 ONLINE
服务器。
mysql> SELECT * FROM performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+----------------------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | MEMBER_ROLE | MEMBER_VERSION | MEMBER_COMMUNICATION_STACK |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+----------------------------+
| group_replication_applier | 395409e1-6dfa-11e6-970b-00212844f856 | s1 | 3306 | ONLINE | PRIMARY | 9.0.0 | XCom |
| group_replication_applier | ac39f1e6-6dfa-11e6-a69d-00212844f856 | s2 | 3306 | ONLINE | SECONDARY | 9.0.0 | XCom |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+----------------------------+
当 s2 尝试加入组时,第 20.5.4 节,“分布式恢复” 确保 s2 应用了与 s1 应用的相同事务。完成此过程后,s2 就可以作为成员加入组,此时它会被标记为 ONLINE
。换句话说,它一定已经自动赶上了服务器 s1。一旦 s2 处于 ONLINE
状态,它就会开始与组一起处理事务。验证 s2 是否确实已与服务器 s1 同步,如下所示。
mysql> SHOW DATABASES LIKE 'test';
+-----------------+
| Database (test) |
+-----------------+
| test |
+-----------------+
mysql> SELECT * FROM test.t1;
+----+------+
| c1 | c2 |
+----+------+
| 1 | Luis |
+----+------+
mysql> SHOW BINLOG EVENTS;
+---------------+------+----------------+-----------+-------------+--------------------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+---------------+------+----------------+-----------+-------------+--------------------------------------------------------------------+
| binlog.000001 | 4 | Format_desc | 2 | 123 | Server ver: 9.0.0-log, Binlog ver: 4 |
| binlog.000001 | 123 | Previous_gtids | 2 | 150 | |
| binlog.000001 | 150 | Gtid | 1 | 211 | SET @@SESSION.GTID_NEXT= 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:1' |
| binlog.000001 | 211 | Query | 1 | 270 | BEGIN |
| binlog.000001 | 270 | View_change | 1 | 369 | view_id=14724832985483517:1 |
| binlog.000001 | 369 | Query | 1 | 434 | COMMIT |
| binlog.000001 | 434 | Gtid | 1 | 495 | SET @@SESSION.GTID_NEXT= 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:2' |
| binlog.000001 | 495 | Query | 1 | 585 | CREATE DATABASE test |
| binlog.000001 | 585 | Gtid | 1 | 646 | SET @@SESSION.GTID_NEXT= 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:3' |
| binlog.000001 | 646 | Query | 1 | 770 | use `test`; CREATE TABLE t1 (c1 INT PRIMARY KEY, c2 TEXT NOT NULL) |
| binlog.000001 | 770 | Gtid | 1 | 831 | SET @@SESSION.GTID_NEXT= 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:4' |
| binlog.000001 | 831 | Query | 1 | 890 | BEGIN |
| binlog.000001 | 890 | Table_map | 1 | 933 | table_id: 108 (test.t1) |
| binlog.000001 | 933 | Write_rows | 1 | 975 | table_id: 108 flags: STMT_END_F |
| binlog.000001 | 975 | Xid | 1 | 1002 | COMMIT /* xid=30 */ |
| binlog.000001 | 1002 | Gtid | 1 | 1063 | SET @@SESSION.GTID_NEXT= 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:5' |
| binlog.000001 | 1063 | Query | 1 | 1122 | BEGIN |
| binlog.000001 | 1122 | View_change | 1 | 1261 | view_id=14724832985483517:2 |
| binlog.000001 | 1261 | Query | 1 | 1326 | COMMIT |
+---------------+------+----------------+-----------+-------------+--------------------------------------------------------------------+
如上所示,第二个服务器已添加到组中,并且它已自动复制了来自服务器 s1 的更改。换句话说,在 s2 加入组的时刻之前在 s1 上应用的事务已复制到 s2。
将更多实例添加到组中与添加第二个服务器的步骤基本相同,只是必须更改配置,就像对服务器 s2 所做的那样。为了总结所需的命令
创建配置文件。
[mysqld] # # Disable other storage engines # disabled_storage_engines="MyISAM,BLACKHOLE,FEDERATED,ARCHIVE,MEMORY" # # Replication configuration parameters # server_id=3 gtid_mode=ON enforce_gtid_consistency=ON # # Group Replication configuration # plugin_load_add='group_replication.so' group_replication_group_name="aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa" group_replication_start_on_boot=off group_replication_local_address= "s3:33061" group_replication_group_seeds= "s1:33061,s2:33061,s3:33061" group_replication_bootstrap_group= off
启动服务器并连接到它。创建用于分布式恢复的复制用户。
SET SQL_LOG_BIN=0; CREATE USER rpl_user@'%' IDENTIFIED BY 'password'; GRANT REPLICATION SLAVE ON *.* TO rpl_user@'%'; GRANT CONNECTION_ADMIN ON *.* TO rpl_user@'%'; GRANT BACKUP_ADMIN ON *.* TO rpl_user@'%'; GRANT GROUP_REPLICATION_STREAM ON *.* TO rpl_user@'%'; FLUSH PRIVILEGES; SET SQL_LOG_BIN=1;
如果您使用
CHANGE REPLICATION SOURCE TO
语句提供用户凭据,请在执行完该语句后执行以下语句mysql> CHANGE REPLICATION SOURCE TO SOURCE_USER='rpl_user', -> SOURCE_PASSWORD='password' -> FOR CHANNEL 'group_replication_recovery';
如有必要,安装组复制插件。
mysql> INSTALL PLUGIN group_replication SONAME 'group_replication.so';
启动组复制。
mysql> START GROUP_REPLICATION;
或者,如果您在
START GROUP_REPLICATION
语句中提供分布式恢复的用户凭据mysql> START GROUP_REPLICATION USER='rpl_user', PASSWORD='password';
此时,服务器 s3 已经启动并运行,已加入组并与组中的其他服务器同步。再次查看 performance_schema.replication_group_members
表可以确认这一点。
mysql> SELECT * FROM performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+----------------------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | MEMBER_ROLE | MEMBER_VERSION | MEMBER_COMMUNICATION_STACK |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+----------------------------+
| group_replication_applier | 395409e1-6dfa-11e6-970b-00212844f856 | s1 | 3306 | ONLINE | PRIMARY | 9.0.0 | XCom |
| group_replication_applier | 7eb217ff-6df3-11e6-966c-00212844f856 | s3 | 3306 | ONLINE | SECONDARY | 9.0.0 | XCom |
| group_replication_applier | ac39f1e6-6dfa-11e6-a69d-00212844f856 | s2 | 3306 | ONLINE | SECONDARY | 9.0.0 | XCom |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+----------------------------+
在服务器 s2 或服务器 s1 上执行相同的查询会得到相同的结果。此外,您还可以验证服务器 s3 已经同步完成。
mysql> SHOW DATABASES LIKE 'test';
+-----------------+
| Database (test) |
+-----------------+
| test |
+-----------------+
mysql> SELECT * FROM test.t1;
+----+------+
| c1 | c2 |
+----+------+
| 1 | Luis |
+----+------+
mysql> SHOW BINLOG EVENTS;
+---------------+------+----------------+-----------+-------------+--------------------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+---------------+------+----------------+-----------+-------------+--------------------------------------------------------------------+
| binlog.000001 | 4 | Format_desc | 3 | 123 | Server ver: 9.0.0-log, Binlog ver: 4 |
| binlog.000001 | 123 | Previous_gtids | 3 | 150 | |
| binlog.000001 | 150 | Gtid | 1 | 211 | SET @@SESSION.GTID_NEXT= 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:1' |
| binlog.000001 | 211 | Query | 1 | 270 | BEGIN |
| binlog.000001 | 270 | View_change | 1 | 369 | view_id=14724832985483517:1 |
| binlog.000001 | 369 | Query | 1 | 434 | COMMIT |
| binlog.000001 | 434 | Gtid | 1 | 495 | SET @@SESSION.GTID_NEXT= 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:2' |
| binlog.000001 | 495 | Query | 1 | 585 | CREATE DATABASE test |
| binlog.000001 | 585 | Gtid | 1 | 646 | SET @@SESSION.GTID_NEXT= 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:3' |
| binlog.000001 | 646 | Query | 1 | 770 | use `test`; CREATE TABLE t1 (c1 INT PRIMARY KEY, c2 TEXT NOT NULL) |
| binlog.000001 | 770 | Gtid | 1 | 831 | SET @@SESSION.GTID_NEXT= 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:4' |
| binlog.000001 | 831 | Query | 1 | 890 | BEGIN |
| binlog.000001 | 890 | Table_map | 1 | 933 | table_id: 108 (test.t1) |
| binlog.000001 | 933 | Write_rows | 1 | 975 | table_id: 108 flags: STMT_END_F |
| binlog.000001 | 975 | Xid | 1 | 1002 | COMMIT /* xid=29 */ |
| binlog.000001 | 1002 | Gtid | 1 | 1063 | SET @@SESSION.GTID_NEXT= 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:5' |
| binlog.000001 | 1063 | Query | 1 | 1122 | BEGIN |
| binlog.000001 | 1122 | View_change | 1 | 1261 | view_id=14724832985483517:2 |
| binlog.000001 | 1261 | Query | 1 | 1326 | COMMIT |
| binlog.000001 | 1326 | Gtid | 1 | 1387 | SET @@SESSION.GTID_NEXT= 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:6' |
| binlog.000001 | 1387 | Query | 1 | 1446 | BEGIN |
| binlog.000001 | 1446 | View_change | 1 | 1585 | view_id=14724832985483517:3 |
| binlog.000001 | 1585 | Query | 1 | 1650 | COMMIT |
+---------------+------+----------------+-----------+-------------+--------------------------------------------------------------------+