mysql5.7 MGR配置
1. 规划
2 连接master报错， 使用主机名连接，所有需要修改主机 /etc/hosts
cat /etc/hosts
127.0.0.1 localhost
172.18.12.2 master
172.18.12.3 slave1
172.18.12.4 slave2
172.18.12.5 slave3
172.18.12.6 slave4
3.设置mysql启动参数
#关于group replication 一些参数
master_info_repository = TABLE relay_log_info_repository = TABLE relay_log_recovery=1 gtid_mode = on enforce_gtid_consistency = 1 log_slave_updates = ON
binlog_checksum=NONE
slave_preserve_commit_order = ON #开启并行复制相关
server_id=1 #第一个节点是1 ，第二个节点是2 ......
slave_parallel_type=LOGICAL_CLOCK
slave_parallel_workers=2-8 #根据cpu数量 transaction_write_set_extraction=XXHASH64 loose-group_replication_group_name="aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa" loose-group_replication_start_on_boot=off loose-group_replication_local_address="172.18.12.2:23306" loose-group_replication_group_seeds="172.18.12.2:23306,172.18.12.3:23306,172.18.12.4:23306,172.18.12.5:23306,172.18.12.6:23306" loose-grup_replication_bootstrap_group=off
4.初始化：
mysqld --initialize
5.第一个节点启动
mysqld --defaults-file=/etc/my.cnf &
6. 登录到mysql， 创建一个账户，不记录到binlog中
mysql -u root -p
set sql_log_bin=0;
create user 'feng'@'172.18.12.%'; grant replication slave on *.* to 'feng'@'172.18.12.%' identified by '123456'; set sql_log_bin=1;
7. channel 的名字不能改变
root@localhost 03:07: [(none)]> change master to master_user='feng', master_password='123456' FOR CHANNEL 'group_replication_recovery';
8. 安装 加载group_replication插件
install plugin group_replication soname 'group_replication.so'; show plugins;
9. 查看group相关参数
root@localhost 03:11: [(none)]> show global variables like '%group%';
10. 设置第一个节点启动为on
set global group_replication_bootstrap_group=on; #只在第一个节点使用
11. 启动group_replication
start group_replication;
#启动后报错
2020-03-25T13:31:11.636568+08:00 6 [Warning] Plugin group_replication reported: 'Group Replication requires slave-preserve-commit-order to be set to ON when using more than 1 applier threads.'
slave_preserve_commit_order=on #并行复制相关
12. 查看是否加入到组中
select * from performance_schema.replication_group_members;
root@localhost 05:50: [performance_schema]> select * from replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | a59bc963-5772-11ea-93aa-0242ac120c02 | master | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
二、加入二个节点172.18.12.3 节点
2.设置mysql启动参数
#关于group replication 一些参数
master_info_repository = TABLE
relay_log_info_repository = TABLE
relay_log_recovery=1
gtid_mode = on
enforce_gtid_consistency = 1
log_slave_updates = ON
server_id=2 #第一个节点是1 ，第二个节点是2 ......
binlog_checksum=NONE
slave_preserve_commit_order = ON #开启并行复制相关
slave_parallel_type=LOCIGCAL_CLOCK
slave_parallel_workers=2-8 #根据cpu数量
transaction_write_set_extraction=XXHASH64
loose-group_replication_group_name="aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa"
loose-group_replication_start_on_boot=off
loose-group_replication_local_address="172.18.12.3:23306"
loose-group_replication_group_seeds="172.18.12.2:23306,172.18.12.3:23306,172.18.12.4:23306,172.18.12.5:23306,172.18.12.6:23306"
loose-grup_replication_bootstrap_group=off
初始化mysql，启动mysql
mysql --initialize
mysqld --defaults-file=/etc/my.cnf &
5. 登录到mysql， 创建一个账户，不记录到binlog中
mysql -u root -p
set sql_log_bin=0; create user 'feng'@'172.18.12.%'; grant replication slave on *.* to 'feng'@'172.18.12.%' identified by '123456'; set sql_log_bin=1;
6. channel 的名字不能改变
root@localhost 03:07: [(none)]> change master to master_user='feng', master_password='123456' FOR CHANNEL 'group_replication_recovery';
7. 安装 加载group_replication插件
install plugin group_replication soname 'group_replication.so';
show plugins;
10. 启动group_replication
set global group_replication_allow_local_disjoint_gtids_join=ON;
start group_replication;
11. 查看状态：
root@localhost 07:12: [(none)]> show slave status for channel 'group_replication_recovery' \G; *************************** 1. row *************************** Slave_IO_State: Master_Host: master Master_User: rpl_user Master_Port: 3306 Connect_Retry: 60 Master_Log_File: Read_Master_Log_Pos: 4 Relay_Log_File: slave1-relay-bin-group_replication_recovery.000001 Relay_Log_Pos: 4 Relay_Master_Log_File: Slave_IO_Running: No Slave_SQL_Running: Yes Replicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0 Last_Error: Skip_Counter: 0 Exec_Master_Log_Pos: 0 Relay_Log_Space: 1534 Until_Condition: SQL_VIEW_ID Until_Log_File: Until_Log_Pos: 0 Master_SSL_Allowed: No Master_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: 0 Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 2005 Last_IO_Error: error connecting to master 'rpl_user@master:3306' - retry-time: 60 retries: 1 Last_SQL_Errno: 0 Last_SQL_Error: Replicate_Ignore_Server_Ids: Master_Server_Id: 0 Master_UUID: Master_Info_File: mysql.slave_master_info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates Master_Retry_Count: 1 Master_Bind: Last_IO_Error_Timestamp: 200225 07:15:55 Last_SQL_Error_Timestamp: Master_SSL_Crl: Master_SSL_Crlpath: Retrieved_Gtid_Set: Executed_Gtid_Set: Auto_Position: 1 Replicate_Rewrite_DB: Channel_Name: group_replication_recovery Master_TLS_Version: 1 row in set (0.00 sec) ERROR: No query specified
再次查看：
root@localhost 07:20: [(none)]> show slave status for channel 'group_replication_recovery' \G; *************************** 1. row *************************** Slave_IO_State: Master_Host: <NULL> Master_User: rpl_user Master_Port: 0 Connect_Retry: 60 Master_Log_File: Read_Master_Log_Pos: 4 Relay_Log_File: slave1-relay-bin-group_replication_recovery.000001 Relay_Log_Pos: 4 Relay_Master_Log_File: Slave_IO_Running: No Slave_SQL_Running: No Replicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0 Last_Error: Skip_Counter: 0 Exec_Master_Log_Pos: 0 Relay_Log_Space: 496 Until_Condition: None Until_Log_File: Until_Log_Pos: 0 Master_SSL_Allowed: No Master_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: NULL Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 0 Last_SQL_Error: Replicate_Ignore_Server_Ids: Master_Server_Id: 0 Master_UUID: Master_Info_File: mysql.slave_master_info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Master_Retry_Count: 1 Master_Bind: Last_IO_Error_Timestamp: Last_SQL_Error_Timestamp: Master_SSL_Crl: Master_SSL_Crlpath: Retrieved_Gtid_Set: Executed_Gtid_Set: 09440083-2b74-11ea-838b-549f3510fe78:1-4 Auto_Position: 1 Replicate_Rewrite_DB: Channel_Name: group_replication_recovery Master_TLS_Version: 1 row in set (0.00 sec) ERROR: No query specified
11. 查看是否加入到组中
root@localhost 07:21: [performance_schema]> select * from replication_group_members; +---------------------------+--------------------------------------+-------------+-------------+--------------+ | CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | +---------------------------+--------------------------------------+-------------+-------------+--------------+ | group_replication_applier | 66576b31-579b-11ea-b037-0242ac120c02 | master | 3306 | ONLINE | | group_replication_applier | 6808a18a-579b-11ea-97cd-0242ac120c03 | slave1 | 3306 | ONLINE | | group_replication_applier | 695065b9-579b-11ea-a932-0242ac120c05 | slave3 | 3306 | ONLINE | | group_replication_applier | 6bc82210-579b-11ea-bb3b-0242ac120c04 | slave2 | 3306 | ONLINE | +---------------------------+--------------------------------------+-------------+-------------+--------------+ 4 rows in set (0.00 sec)
配置出现的问题：
1 [ERROR] Plugin group_replication reported: 'Gtid mode should be ON for Group Replication'
没有打开GtID
2 Last_IO_Error: error connecting to master 'rpl_user@master:3306' - retry-time: 60 retries: 1
添加所有节点的主机名和ip的对应关系到/etc/hosts
3. [ERROR] Plugin group_replication reported: '[GCS] Error on opening a connection to 172.17.12.6:23306 on local port: 23306.
/etc/my.cnf 配置文件 loose-group_replication_group_seeds ip地址写错了
4. 第二个节点加入MGR时报错[
ERROR] Plugin group_replication reported: 'This member has more executed transactions than those present in the group. Local transactions: f9418f39-8f6a-11ea-8e60-005056841c10:1 > Group transactions: 6c0d784d-8f66-11ea-bd2e-00505684742a:1,
aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:1-5'
2020-05-06T16:09:46.375914+08:00 0 [ERROR] Plugin group_replication reported: 'The member contains transactions not present in the group. The member will now exit the group.'
解决办法 需要设置参数,也就是兼容加入组
set global group_replication_allow_local_disjoint_gtids_join=ON;
12 创建测试数据库（master可以写入，其他节点不能写入）
master:
root@localhost 05:52: [fengjian]> create database fengjian; root@localhost 05:52: [fengjian]> use fengjian; root@localhost 05:52: [fengjian]> create table test(id int, name varchar(60), primary key(id)); root@localhost 05:52: [fengjian]> insert into test values(1,'feng');
slave: 报错，无法写入
root@localhost 08:18: [fengjian]> insert into test values(2,'su');
ERROR 1290 (HY000): The MySQL server is running with the --super-read-only option so it cannot execute this statement
查看其他节点所有节点的read_only 选项
master
slave1
Group replication 工作模式
1. 基于single-master 环境：
在group replication 配置中，默认模式是 single-master 模式， 只有一个节点可以进行写操作，其他节点开启 --super-read-only 模式， 当主几点挂了， 其他节点会选出来一个新的master
在 single-master 上查看那个节点是 主节点：
root@localhost 08:25: [performance_schema]> select variable_value from global_status where variable_name='group_replication_primary_member'; +--------------------------------------+ | variable_value | +--------------------------------------+ | 43567e06-6e49-11ea-a1ef-0242ac110003 | +--------------------------------------+
登录到 其他节点上，查看 uuid
root@localhost 08:27: [fengjian]> select @@server_uuid; +--------------------------------------+ | @@server_uuid | +--------------------------------------+ | 43567e06-6e49-11ea-a1ef-0242ac110003 |
+--------------------------------------+
multi-master 模式 （多主，性能有15%的损失）
如果要开启multi-master 模式，需要在配置文件/etc/my.cnf 中指定
loose-group_replication_single_primary_mode=OFF;
loose-group_replication_enforce_update_everywhere_checks=ON;
不管是 single-master 还是 multi-master ，我们只提供一台负责写操作
集群重启：
1. 滚动重启
节点上执行 ： start group_replication;
2. 全部一起重启（集体掉电）
第一个节点启动(single-master 和 multi-master 都一样)
要在每个节点执行 show master stauts; 如果那个gtid多，则设置成主节点。 set global_replication_bootstrap_group=on; start group_replication;
其他节点 start group-replication;
MGR 监控点讲解：
可用性监控
root@localhost 09:28: [performance_schema]> select member_id,member_host,member_state from replication_group_members where member_id=@@server_uuid; +--------------------------------------+-------------+--------------+ | member_id | member_host | member_state | +--------------------------------------+-------------+--------------+ | 66576b31-579b-11ea-b037-0242ac120c02 | master | ONLINE | +--------------------------------------+-------------+--------------+
查看当前是不是可读
root@localhost 09:32: [performance_schema]> select * from performance_schema.global_variables where variable_name in ('read_only', 'super_read_only'); +-----------------+----------------+ | VARIABLE_NAME | VARIABLE_VALUE | +-----------------+----------------+ | read_only | OFF | | super_read_only | OFF | +-----------------+----------------+
为可读节点
复制是不是存在延迟：
对比获得到的GTID和本节点执行的GTID是不是一致：
从远程获取的GTID：
SELECT Received_transaction_set FROM performance_schema.replication_connection_status WHERE Channel_name = 'group_replication_applier';
本节点执行的GTID：
select @@global.gtid_executed; 不显示结果
root@localhost 09:47: [performance_schema]> show global variables like '%gtid_executed%';
+----------------------------------+--------------------------------------------+
| Variable_name | Value |
+----------------------------------+--------------------------------------------+
| gtid_executed | 09440083-2b74-11ea-838b-549f3510fe78:1-977 |
远程获取的GTID - 本节点执行的GTID = 延迟的GTID数
本节点执行队列是不是有堆积(大于0表示有延迟）：
select count_transactions_in_queue from replication_group_member_stats where member_id=@@server_uuid;
流控(flow control)
在MGR中如果节点落后集群中其它成员太多，就会发起让其它节点等他完成在做的控制，这个叫流控。
当启用：
group_replication_flow_control_mode=QUOTA 是表示启用流控。 流控默认通过两个参数控制： group_replication_flow_control_applier_threshold (默认: 25000) group_replication_flow_control_certifier_threshold (默认: 25000)
也就说默认延迟在25000个GTID时，会对整个集群Block住写操作。
当然，也可以允许，节点延迟，就如同我们主从结构，从节点延迟，不往上面发请求就可以。
关闭流控：
set global group_replication_flow_control_mode='DISABLED';
提示： 关闭流控制，注意查看是不是存在延迟，如果延迟，自已控制阀值不向上面发请求即可。 多IDC结构的MGR，建议关闭流控。
MGR调优参数
因为基本复制结构，所有的数据复制，还是逻辑的重放，所以优化也是复制优化点。
更改：
slave_parallel_type -> LOGICAL_CLOCK #增强sql_thread个数：
slave_parallel_workers -> 2-8 #如果CPU瓶颈，网络没问题，减少CPU压缩：
group_replication_compression_threshold = 1000000 -> 2000000 由原来的1M变成2M，再进行压缩（主要针对大事务传述优化）
MGR备份及新节点的加入
1. 通过备份工具，建立备份 2. 加载MGR插件 3. mysqldump -u root --single-transaction -A > full_bak.sql 其他从库，备份
4. 新加入的mgr节点配置文件
transaction_write_set_extraction=XXHASH64
loose-group_replication_group_name="aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa"
loose-group_replication_start_on_boot=off
loose-group_replication_local_address="172.18.12.7:23306"
loose-group_replication_group_seeds="172.18.12.2:23306,172.18.12.3:23306,172.18.12.4:23306,172.18.12.5:23306,172.18.12.6:23306,172.18.12.7:23306"
loose-group_replication_bootstrap_group=off
5. mysql -u root -p ; reset master ; mysql -u root -p < full_bak.sql 6. 可以加入集群的关键点： set global gtid_purged='xxx-xxxx-xxxx:id'
7. start group_replication;
8. use performance_schema; select * from replication_group_members;
root@localhost 08:52: [performance_schema]> show slave status FOR CHANNEL 'group_replication_recovery' \G
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: <NULL>
Master_User: rpl_user
Master_Port: 0
Connect_Retry: 60
Master_Log_File:
Read_Master_Log_Pos: 4
Relay_Log_File: slave3-relay-bin-group_replication_recovery.000001
Relay_Log_Pos: 4
Relay_Master_Log_File:
Slave_IO_Running: No
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 0
Relay_Log_Space: 496
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: NULL
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 0
Master_UUID:
Master_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State:
Master_Retry_Count: 1
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set: 09440083-2b74-11ea-838b-549f3510fe78:1-896
Auto_Position: 1
Replicate_Rewrite_DB:
Channel_Name: group_replication_recovery
Master_TLS_Version:
如果binlog已经过期， start group_replication 启动报错，因为从库的gtid信息已经删除了，
引用
https://www.cnblogs.com/manger/p/7212039.html
