此时,组中只有一个成员,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,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
等内容。
[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
与服务器 s1 的过程类似,在配置文件到位后,您启动服务器。然后配置分布式恢复凭据,如下所示。这些命令与在将服务器 s1 设置为主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,“用于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,复制用户将被复制或克隆到 s1。如果您在服务器 s1 上配置用户凭据时未启用二进制日志,并且未对状态传输使用远程克隆操作,则必须在服务器 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;
如果您使用的是 CHANGE REPLICATION SOURCE TO
提供用户凭据,请在之后发出以下语句
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(默认值),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
语句中提供用于分布式恢复的用户凭据
mysql> START GROUP_REPLICATION USER='rpl_user', PASSWORD='password';
与在 s1 上执行的相同步骤不同,这里有所不同,因为您 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;
,因为该组已经由服务器 s1 创建并引导。此时,服务器 s2 只需要添加到已经存在的组中。
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,您可以确保在启动组复制时由于任何原因而发生故障的服务器不会接受事务。如果服务器应该作为读写实例加入组,例如作为单主组中的主服务器或作为多主组的成员,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 | 8.4.0 | XCom |
| group_replication_applier | ac39f1e6-6dfa-11e6-a69d-00212844f856 | s2 | 3306 | ONLINE | SECONDARY | 8.4.0 | 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。此过程完成后,s2 可以作为成员加入组,此时它被标记为 ONLINE
。换句话说,它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: 8.4.0-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服务器 s1 的更改。换句话说,在 s2 加入组之前在 s1 上应用的事务已复制到 s2。
将其他实例添加到组中与添加第二个服务器的步骤基本相同,只是配置必须与 s2 类似进行更改。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;
如果您使用的是
CHANGE REPLICATION SOURCE TO
语句提供用户凭据,请在之后发出以下语句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
语句中提供用于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 已启动并运行,已加入组并赶上了组中的其他服务器。再次查看 performance_schema.replication_group_members
表确认了这种情况。
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 | 8.4.0 | XCom |
| group_replication_applier | 7eb217ff-6df3-11e6-966c-00212844f856 | s3 | 3306 | ONLINE | SECONDARY | 8.4.0 | XCom |
| group_replication_applier | ac39f1e6-6dfa-11e6-a69d-00212844f856 | s2 | 3306 | ONLINE | SECONDARY | 8.4.0 | XCom |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+----------------------------+
在服务器 s2 或服务器 s1 上发出相同的查询会得到相同的结果。此外,您可以验证服务器 s3 已经赶上来了。
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: 8.4.0-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 |
+---------------+------+----------------+-----------+-------------+--------------------------------------------------------------------+