关于mysql组复制从5.7.17就有了。本文主要是记录一下操作步骤，以及相应的坑点。
mysql 单主模式的组复制配置
三台机器 10.50.31.7,10.50.31.8,10.50.31.18
31.7上配置
my.cnf配置
server_id=1
log-bin=mysql-bin
log-bin-index=mysql-bin.index
relay-log=relay-log
#expire-logs-days=7
binlog_expire_logs_seconds=159200
port=3306
report-host='10.50.31.7'
binlog-format=row
gtid-mode=on
enforce_gtid_consistency=on
log_slave_updates=on
master_info_repository=table
relay_log_info_repository=table
binlog_checksum=none
transaction_write_set_extraction=XXHASH64
loose-group_replication_group_name='12345678-1234-1234-1234-1234567890ab'
loose-group_replication_start_on_boot=off
loose-group_replication_bootstrap_group=off
loose-group_replication_local_address='10.50.31.7:24901'
#slave-parallel-type='LOGICAL_CLOCK'
#slave-parallel-workers=3
#slave-preserve-commit-order=on
loose-group_replication_group_seeds='10.50.31.7:24901,10.50.31.8:24901,10.50.31.18:24901'
transaction_isolation = READ-COMMITTED
loose-group_replication_single_primary_mode = off
loose-group_replication_enforce_update_everywhere_checks = on
(注意在这里有一个坑，就是启动的24901端口，可能需要关闭防火墙,如果是demo执行 /usr/sbin/setenforce 0 即可)
重启mysql,并连接上mysql server,执行如下sql:
set sql_log_bin=0;
create user repl_user@'%' identified by 'NewRepl4!';
grant replication slave on *.* to repl_user@'%' ;
flush privileges;
set sql_log_bin=1;
install plugin group_replication soname 'group_replication.so';
change master to master_user='repl_user',master_password='NewRepl4!'
for channel 'group_replication_recovery';
31.8上配置
my.cnf配置
server_id=2
log-bin=mysql-bin
log-bin-index=mysql-bin.index
log-slave-updates=on
relay-log=relay-log
#expire-logs-days=7
binlog_expire_logs_seconds=159200
port=3306
report-host='10.50.31.8'
gtid-mode=on
enforce-gtid-consistency=on
binlog-format=row
binlog-checksum=none
master-info-repository=table
relay-log-info-repository=table
transaction-write-set-extraction=MURMUR32
#slave-parallel-type='LOGICAL_CLOCK'
#slave-parallel-workers=3
#slave-preserve-commit-order=on
loose-group_replication_group_name='12345678-1234-1234-1234-1234567890ab'
loose-group_replication_local_address='10.50.31.8:24901'
loose-group_replication_group_seeds='10.50.31.7:24901,10.50.31.8:24901,10.50.31.18:24901'
loose-group_replication_bootstrap_group=off
loose-group_replication_start_on_boot=off
重启mysql,并连接上mysql server,执行如下sql:
set sql_log_bin=0;
create user repl_user@'%' identified by 'NewRepl4!';
grant replication slave on *.* to repl_user@'%' ;
flush privileges;
set sql_log_bin=1;
install plugin group_replication soname 'group_replication.so';
change master to master_user='repl_user',master_password='NewRepl4!'
for channel 'group_replication_recovery';
31.15上配置(同31.8，注意修改ip端口号、server_id 等）
31.15也完成相应的配置，重启数据库，执行完相应的sql,我们以 31.7作为主库进行组引导初始化组复制。
再次回到31.7
接着执行如下sql
SET GLOBAL group_replication_bootstrap_group=ON;
start group_replication;
set global group_replication_bootstrap_group=off;
--查看组员情况
select *From performance_schema.replication_group_members;
回到31.8
接着执行如下sql（注意与31.7的区别）
start group_replication;
如果有binlog错误，执行
stop group_replication;
reset master;(5.7版本可以执行set global group_replication_allow_local_disjoint_gtids_join=on;）
start group_replication;
回到31.18
执行步骤与31.8一样；
