Step 1 . 准备工作
关闭防火墙; 安装 MySQL依赖于libaio 库；下载，解压，重命名 MySQL的执行文件；新建用户组和用户 等准备工作在此不再赘述。
可执行文件目录为 /data/mysql57
添加用户和组的指令
groupadd mysql useradd mysql -g mysql
Step 2 . 添加环境变量
在/etc/profile文件中，追加 PATH=${PATH}:/data/mysql57/bin/
保存后，如需要立即生效，可执行 source /etc/profile 。
step 3 . 创建目录并授权
在data根目录下执行
mkdir -p mysql3306/data mysql3306/mysql_log mysql3306/tmp mysql3307/data mysql3307/mysql_log mysql3307/tmp mysqld_multi/log
创建记录log的文件，此步骤不可少。
touch /data/mysql3306/mysql_log/mysql3306.errtouch /data/mysql3307/mysql_log/mysql3307.err
赋予目录和文件权限
chown -R mysql.mysql mysql3* mysqld_multi
在本测试案例中，mysql57是从其它服务上copy来的，不是直接下载解压的，所以多了下面的两步授权操作。
chmod -R 755 /data/mysql57/bin
chmod -R 755 /data/mysql57/support-files
step 4 . 编辑my.cnf
[client] host=localhost socket = /tmp/mysql.sock default-character-set=utf8mb4 #loose-local-infile=0 [mysqld] user=mysql log_bin_trust_function_creators=1 secure_file_priv='/tmp' ########server setting####### sql_mode = "ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION" character-set-server=utf8mb4 collation_server=utf8mb4_unicode_ci lower_case_table_names = 0 skip_name_resolve = 1 #max_connect_errors = 1000 max_connections = 2000 thread_cache_size=256 #thread_stack= 262144 #back_log=80 max_allowed_packet = 134217728 event_scheduler = 1 local-infile=0 #lower_case_table_names = 1 explicit_defaults_for_timestamp = 1 expire_logs_days = 7 log_bin_trust_function_creators =1 ####.frm/.ibd files qty related open_files_limit=65535 innodb_open_files=65535 table_open_cache=65535 table_definition_cache=65535 #### seesion buffer related read_buffer_size = 262144 read_rnd_buffer_size = 524288 sort_buffer_size = 8388608 join_buffer_size = 8388608 ####memory table size tmp_table_size =67108864 max_heap_table_size=67108864 ####timeout interactive_timeout = 1800 wait_timeout = 1800 # connect_timeout=10 ########slow query ######## slow_query_log = 1 log_slow_slave_statements = 1 #log_queries_not_using_indexes = 1 log_throttle_queries_not_using_indexes = 10 long_query_time = 1 #min_examined_row_limit = 10000 ########innodb settings######## innodb_buffer_pool_size = 10737418240 innodb_buffer_pool_instances = 16 innodb_buffer_pool_dump_pct = 40 innodb_lru_scan_depth = 2048 innodb_page_cleaners = 16 #innodb_purge_threads = 4 innodb_sort_buffer_size = 67108864 #innodb_file_per_table = 1 #innodb_flush_log_at_trx_commit = 1 innodb_undo_log_truncate = 1 innodb_undo_tablespaces = 3 innodb_max_undo_log_size = 2147483648 innodb_purge_rseg_truncate_frequency = 128 innodb_log_file_size = 1073741824 innodb_log_files_in_group = 3 innodb_log_buffer_size = 16777216 innodb_flush_method = O_DIRECT innodb_flush_neighbors = 0 innodb_print_all_deadlocks = 1 innodb_strict_mode = 1 #innodb_lock_wait_timeout = 50 innodb_io_capacity = 32768 innodb_io_capacity_max = 65536 innodb_thread_concurrency = 32 innodb_write_io_threads = 8 innodb_read_io_threads = 8 ########replication settings######## master_info_repository = TABLE relay_log_info_repository = TABLE gtid_mode = on enforce_gtid_consistency = 1 binlog_gtid_simple_recovery=1 relay_log_recovery = 1 slave-parallel-type = LOGICAL_CLOCK slave-parallel-workers = 16 slave_transaction_retries=128 slave_preserve_commit_order=1 log_slave_updates=1 binlog_format = ROW log_timestamps=system binlog_rows_query_log_events = 1 binlog_row_image='full' slave_skip_errors = ddl_exist_errors ########semi sync replication settings######## ##plugin_dir=/data/mysql/plugin/ #plugin_load = "rpl_semi_sync_master=semisync_master.so;rpl_semi_sync_slave=semisync_slave.so" #rpl_semi_sync_master_enabled = 1 #rpl_semi_sync_master_timeout = 5000 #rpl_semi_sync_slave_enabled = 1 [mysqld_multi] mysqld = /data/mysql57/bin/mysqld_safe mysqladmin = /data/mysql57/bin/mysqladmin log = /data/mysqld_multi/log/mysqld_multi.log [mysqld3306] basedir = /data/mysql57 mysqladmin=mysqladmin datadir=/data/mysql3306/data port=3306 server_id=102473306 socket= /tmp/mysql_3306.sock tmpdir = /data/mysql3306/tmp pid-file = /data/mysql3306/mysql_log/mysql3306.pid slow_query_log_file = /data/mysql3306/mysql_log/mysql3306_slow_new.log log-error = /data/mysql3306/mysql_log/mysql3306.err general_log_file= /data/mysql3306/mysql_log/mysql3306.genlog log-bin = /data/mysql3306/mysql_log/mysql3306_bin relay_log = /data/mysql3306/mysql_log/relay3306.log innodb_buffer_pool_size = 90G innodb_buffer_pool_instances = 8 [mysqld3307] basedir = /data/mysql57 mysqladmin=mysqladmin datadir=/data/mysql3307/data port=3307 server_id=102473307 socket= /tmp/mysql_3307.sock tmpdir = /data/mysql3307/tmp pid-file = /data/mysql3307/mysql_log/mysql3307.pid slow_query_log_file = /data/mysql3307/mysql_log/mysql3307_slow_new.log log-error = /data/mysql3307/mysql_log/mysql3307.err general_log_file= /data/mysql3307/mysql_log/mysql3307.genlog log-bin = /data/mysql3307/mysql_log/mysql3307_bin relay_log = /data/mysql3307/mysql_log/relay3307.log innodb_buffer_pool_size = 90G innodb_buffer_pool_instances = 8 [mysqldump] quick
step 5 . 初始化实例
初始化3306端口的实例，注意产生的临时密码。
/data/mysql57/bin/mysqld --defaults-file=/etc/my.cnf --initialize --user=mysql --basedir=/data/mysql57 --datadir=/data/mysql3306/data
初始化3307端口的实例，注意产生的临时密码。
/data/mysql57/bin/mysqld --defaults-file=/etc/my.cnf --initialize --user=mysql --basedir=/data/mysql57 --datadir=/data/mysql3307/data
step 6 . 复制生成mysqld_multi并添加到开机启动
cp /data/mysql57/support-files/mysqld_multi.server /etc/init.d/mysqld_multi
chkconfig --add mysqld_multi
step 7 . 多实例Mysqld的开启
开启全部实例
mysqld_multi start
查看开启情况（查看全部实例状态）
mysqld_multi report
开启指定实例
开启/etc/my.cnf中[mysqld3306]其中mysqld后面的数字为标签，例如3306标签
mysqld_multi start 3306
同样开启3307标签实例
mysqld_multi start 3307
（注意：此处没有说通过 mysqld_multi stop 命令进行关闭实例，为什么不说，因为命令无效。Step 9 的操作会让它变成有效）
step 8 . 第一次登入实例，修改root账号密码
多实例登入需指定 socket 参数
本测试3306实例登入的方式为：
mysql -S /tmp/mysql_3306.sock -uroot --port 3306 -p
step 9 . 赋予通过mysqld_multi stop关闭实例的权限。
关闭实例需要配置root用户及密码， 修改 /etc/my.cnf文件。
在 [client] 位置添加
user=root password=密码
因为文件中需要保留账号密码，有安全风险。实际环境中要不要如此设置，还需根据具体情况和安全要求而定。
经过以上步骤的操作，此服务器成功安装了2个MySQL实例，一个Port为3306，另一个Port为3307
