5.7mysql 多线程slave
1.主库需要设置参数：
server_id=202
log-bin=mysql-bin
binlog_format=row
log-slave-updates
sync_binlog=1
innodb_flush_log_at_trx_commit=1

2.从库配置
server_id=203
log-bin=mysql-bin
binlog_format=row
log-slave-updates
slave-parallel-type=LOGICAL_CLOCK
slave-parallel-workers=8
master_info_repository=TABLE
relay_log_info_repository=TABLE
relay_log_recovery=ON
slave_preserve_commit_order=on
sync_relay_log=100

CHANGE MASTER TO MASTER_HOST='142.60.0.121',MASTER_PORT=3306,MASTER_USER='repl',MASTER_PASSWORD='skyvis_123' ,MASTER_LOG_FILE='mysql-bin.000005',MASTER_LOG_POS=763;