参考文档
https://blog.csdn.net/li123128/article/details/80744568
https://www.cnblogs.com/ctulzq/p/8631097.html
http://www.cnblogs.com/lemon-le/p/9241984.html
https://www.jianshu.com/p/ca1af156f656
首先安装mysql5.7
https://www.cnblogs.com/maobuji/p/8336702.html
服务器信息
| 序号 | 服务器IP | mysql别名 | 端口 |
| 1 | 172.18.100.85 | mgr1 | 3306 |
| 2 | 172.18.100.69 | mgr2 | 3306 |
| 3 | 172.18.100.84 | mgr3 | 3306 |
在三台服务器上设置/etc/hosts的映射，但是不清楚为什么要做这个映射，因为后面也没有碰到配置的地方。
172.18.100.85 mgr1 172.18.100.69 mgr2 172.18.100.84 mgr3
如果机器名都相同，可以修改机器名
hostnamectl set-hostname mgr1
配置三台mysql的配置文件vi /etc/my.cnf,标红色的部分是需要修改的配置。
#-------------------gobal variables------------# gtid_mode = ON enforce_gtid_consistency = ON master_info_repository = TABLE relay_log_info_repository = TABLE binlog_checksum = NONE log_slave_updates = ON log-bin = mysql-bin transaction_write_set_extraction = XXHASH64 loose-group_replication_group_name = '157be252-2b71-11e6-b8f4-00212889f856' loose-group_replication_start_on_boot = off loose-group_replication_bootstrap_group = off loose-group_replication_local_address = '172.18.100.85:33061' loose-group_replication_group_seeds ='172.18.100.85:33061,172.18.100.69:33061,172.18.100.84:33061' loose-group_replication_single_primary_mode = off loose-group_replication_enforce_update_everywhere_checks = on max_connect_errors = 20000 max_connections = 2000 wait_timeout = 3600 interactive_timeout = 3600 net_read_timeout = 3600 net_write_timeout = 3600 table_open_cache = 1024 table_definition_cache = 1024 thread_cache_size = 512 open_files_limit = 10000 character-set-server = utf8 collation-server = utf8_bin skip_external_locking performance_schema = 1 user = mysql myisam_recover_options = DEFAULT skip-name-resolve local_infile = 0 lower_case_table_names = 0 #--------------------innoDB------------# innodb_buffer_pool_size = 2000M #innodb_data_file_path = ibdata1:200M:autoextend innodb_flush_log_at_trx_commit = 1 innodb_io_capacity = 600 innodb_lock_wait_timeout = 120 innodb_log_buffer_size = 8M innodb_log_file_size = 200M innodb_log_files_in_group = 3 innodb_max_dirty_pages_pct = 85 innodb_read_io_threads = 8 innodb_write_io_threads = 8 innodb_support_xa = 1 innodb_thread_concurrency = 32 innodb_file_per_table innodb_rollback_on_timeout #------------session variables-------# join_buffer_size = 8M key_buffer_size = 256M bulk_insert_buffer_size = 8M max_heap_table_size = 96M tmp_table_size = 96M read_buffer_size = 8M sort_buffer_size = 2M max_allowed_packet = 64M read_rnd_buffer_size = 32M #------------MySQL Log----------------# log-bin = my3306-bin binlog_format = row sync_binlog = 1 expire_logs_days = 15 max_binlog_cache_size = 128M max_binlog_size = 500M binlog_cache_size = 64k slow_query_log log-slow-admin-statements log_warnings = 1 long_query_time = 0.25 #---------------replicate--------------# relay-log-index = relay3306.index relay-log = relay3306 server-id =1 init_slave = 'set sql_mode=STRICT_ALL_TABLES' log-slave-updates [myisamchk] key_buffer = 512M sort_buffer_size = 512M read_buffer = 8M write_buffer = 8M [mysqlhotcopy] interactive-timeout [mysqld_safe] open-files-limit = 8192
配置完成后，重新mysql
systemctl restart mysqld
登录mysql在三台机器上都安装组复制插件,可以通过查询状态来检查插件是否已经激活了
mysql -uroot -p mysql>INSTALL PLUGIN group_replication SONAME 'group_replication.so'; mysql>select plugin_name, plugin_status from information_schema.plugins where plugin_name like 'group_%';
需要先进行配置，否则会报错误
ERROR 1123 (HY000): Can't initialize function 'group_replication'; Plugin initialization function failed.
修改linux系统配置/etc/selinux/config文件，修改后要重启系统
SELINUX=disabled
否则可能出现以下错误
ERROR 3092 (HY000): The server is not configured properly to be an active member of the group. Please see more details on error log.
在配置过程中可以随时执行查询命令，查看集群状态
mysql>SELECT * FROM performance_schema.`replication_group_members`;
配置server1，做为主.
mysql -uroot -p
mysql>set sql_log_bin=0;
mysql>GRANT REPLICATION SLAVE ON *.* TO 'repl'@'172.18.100.%' IDENTIFIED BY 'RKYSrkys123!@#';
mysql>flush privileges;
mysql>set sql_log_bin=1;
mysql>CHANGE MASTER TO MASTER_USER='repl',MASTER_PASSWORD='RKYSrkys123!@#' FOR CHANNEL 'group_replication_recovery';
mysql>set global group_replication_ip_whitelist="127.0.0.1/32,172.18.100.0/24";
mysql>SET GLOBAL group_replication_bootstrap_group = ON;
mysql>START GROUP_REPLICATION;
mysql>SET GLOBAL group_replication_bootstrap_group = OFF;
mysql>SELECT * FROM performance_schema.`replication_group_members`;
1.创建并授权一个复制用户
2.FOR CHANNEL 'group_replication_recovery'是一个默认的管道，不能改名
3.创建白名单
在server2，server3上执行
mysql>CHANGE MASTER TO MASTER_USER='repl',MASTER_PASSWORD='RKYSrkys123!@#' FOR CHANNEL 'group_replication_recovery'; mysql>set global group_replication_ip_whitelist="127.0.0.1/32,172.18.100.0/24"; mysql>set global group_replication_allow_local_disjoint_gtids_join=ON; mysql>START GROUP_REPLICATION;
mysql>SELECT * FROM performance_schema.`replication_group_members`;
查看数据库状态
查看数据库的主从状态
SELECT MEMBER_ID,MEMBER_HOST,MEMBER_PORT,MEMBER_STATE,IF(global_status.VARIABLE_NAME IS NOT NULL,'PRIMARY','SECONDARY') AS MEMBER_ROLE FROM performance_schema.replication_group_members
LEFT JOIN performance_schema.global_status ON global_status.VARIABLE_NAME = 'group_replication_primary_member' AND global_status.VARIABLE_VALUE = replication_group_members.MEMBER_ID;
使用host那么可以查看机器名与ip的对应。
命令行获取主机的host
mysql -h127.0.0.1 -uroot -proot -e "SELECT * FROM performance_schema.replication_group_members WHERE MEMBER_ID = (SELECT VARIABLE_VALUE FROM performance_schema.global_status WHERE VARIABLE_NAME= 'group_replication_primary_member')" |awk 'NR==2{print}'|awk -F" " '{print $3}'
如果登录失败，可以设置root登录权限
grant all privileges on *.* to 'root'@'%' identified by 'root' with grant option;
在任意数据库上添加用户，并创建数据库
create user 'studyuser'@'%' identified by 'Study123$%^'; flush privileges; create database citystudy DEFAULT CHARSET utf8 COLLATE utf8_general_ci; grant all privileges on `citystudy`.* to 'studyuser'@'%' identified by 'Study123$%^'; flush privileges;
节点宕机重启
systemctl restart mysqld
mysql重启后，并不会自动加入节点,需要重新执行加入节点命令，主节点
问题处理
服务器长期处于RECOVERING状态（这里没有成功，后续需要跟踪）
一种是因为ip域名或者防火墙导致的连接不上问题。
还有一种是服务器加入集群时，事物就不同步，导致同步失败。 这里处理一下第二种情况：
在集群服务器上分别执行，查看每个服务器的事物状态()
mysql>select * from performance_schema.replication_group_member_stats G ;
正常的服务器
*************************** 1. row ***************************
CHANNEL_NAME: group_replication_applier
VIEW_ID: 15452040099672487:7
MEMBER_ID: 24f6893f-00fc-11e9-aefc-005056ac3343
COUNT_TRANSACTIONS_IN_QUEUE: 0
COUNT_TRANSACTIONS_CHECKED: 1
COUNT_CONFLICTS_DETECTED: 0
COUNT_TRANSACTIONS_ROWS_VALIDATING: 2
TRANSACTIONS_COMMITTED_ALL_MEMBERS: 157be252-2b71-11e6-b8f4-00212889f856:1-115:1000003-1000011:2000003,
24f9586e-00fc-11e9-b2e0-005056ac1e09:1-13
LAST_CONFLICT_FREE_TRANSACTION: 157be252-2b71-11e6-b8f4-00212889f856:115
RECOVERING的服务器
*************************** 1. row ***************************
CHANNEL_NAME: group_replication_applier
VIEW_ID: 15452040099672487:7
MEMBER_ID: 24f9586e-00fc-11e9-b2e0-005056ac1e09
COUNT_TRANSACTIONS_IN_QUEUE: 6
COUNT_TRANSACTIONS_CHECKED: 0
COUNT_CONFLICTS_DETECTED: 0
COUNT_TRANSACTIONS_ROWS_VALIDATING: 0
TRANSACTIONS_COMMITTED_ALL_MEMBERS:
LAST_CONFLICT_FREE_TRANSACTION:
停止有问题的服务器的组同步，然后重新设置事物号，之后在重新加入集群
set global gtid_purged='157be252-2b71-11e6-b8f4-00212889f856:1-115:1000003-1000011:2000003,24f9586e-00fc-11e9-b2e0-005056ac1e09:1-13'