一般情况下是1-4个实例，1-2个居多
一、安装环境
二、多实例添加（安装mysql）
三、配置文件的添加
四、启动脚本的添加
五、文件权限及所属
六、配置全局路径
七、初始化数据库
八、mysql启动、关闭、登录
一、安装环境
CentOS Linux release 7.2.1511安装目录：/application/mysql
安装版本：mysql-5.7.9
二、实例的添加（安装mysql）
见博文mysql安装 https://blog.51cto.com/13006632/2457769
mkdir /data/{3306,3307}/data -p三、配置文件my.cnf的添加
[client]
port = 3306 #实例端口，另一个为3307
socket = /data/3306/mysql.sock
[mysql]
no-auto-rehash
[mysqld]
user = mysql
port = 3306
socket =/data/3306/mysql.sock
basedir = /application/mysql
datadir = /data/3306/data
open_files_limit = 1024
back_log = 600
max_connections = 800
max_connect_errors = 3000
table_open_cache = 614
external-locking = FALSE
max_allowed_packet = 8M
sort_buffer_size = 1M
join_buffer_size = 1M
thread_cache_size = 100
query_cache_size = 2M
query_cache_limit = 1M
#default_table_type = InnoDB
thread_stack =192k
#transaction_isolation = READ-COMMITTED
tmp_table_size = 2M
max_heap_table_size = 2M
long_query_time = 1
#log_long_format
#log-error = /data/3306/error.log
#log-slow-queries = /data/3306/slow.log
pid-file = /data/3306/mysql.pid
log-bin = /data/3306/mysql-bin
relay-log =/data/3306/relay-bin
relay-log-info-file = /data/3306/relay-log.info
binlog_cache_size = 1M
max_binlog_cache_size = 1M
max_binlog_size = 2M
expire_logs_days = 7
key_buffer_size = 16M
read_buffer_size = 1M
read_rnd_buffer_size = 1M
bulk_insert_buffer_size = 1M
#myisam_sort_buffer_size = 1M
#myisam_max_extra_sort_file_size = 10G
#uyisam_repair_threads = 1
#yisam_recover
lower_case_table_names = 1
skip-name-resolve
slave-skip-errors = 1032,1062
replicate-ignore-db = mysql
server-id = 8
innodb_buffer_pool_size = 32M
innodb_data_file_path = ibdata1:128M:autoextend
innodb_thread_concurrency =8
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 2M
innodb_log_file_size = 4M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 90
innodb_lock_wait_timeout = 120
innodb_file_per_table = 0
[mysqldump]
quick
max_allowed_packet = 2M
[mysqld_safe]
log-error = /data/3306/mysql_3306.err
pid-file = /data/3306/mysqld.pid四、mysql脚本的添加
#!/bin/sh
#init
port=3306
mysql_user="root"
mysql_pwd="123456"
CmdPath="/application/mysql/bin"
mysql_sock="/data/${port}/mysql.sock"
#startup function
function_start_mysql()
{
if [ ! -e "$mysql_sock" ];then
printf "Starting MySQL...\n"
/bin/sh ${CmdPath}/mysqld_safe --defaults-file=/data/${port}/my.cnf 2>&1 > /dev/null &
else
printf "MySQL is running...\n"
exit
fi
}
#stop function
function_stop_mysql()
{
if [ ! -e "$mysql_sock" ];then
printf "MySQL is stopped...\n"
exit
else
printf "Stoping MySQL...\n"
${CmdPath}/mysqladmin -u${mysql_user} -p${mysql_pwd} -S /data/${port}/mysql.sock shutdown
fi
}
#restart function
function_restart_mysql()
{
printf "Restarting MySQL...\n"
function_stop_mysql
sleep 2
function_start_mysql
}
case $1 in
start)
function_start_mysql
;;
stop)
function_stop_mysql
;;
restart)
function_restart_mysql
;;
*)
printf "Usage: /data/${port}/mysql {start|stop|restart}\n"
esac特别说明：来源于老男孩教育
启动原理
/bin/sh /application/mysql/bin/mysqld_safe --defaults-file=/data/3306/my.cnf
停止原理
/application/mysq/bin/mysqladmin -uroot -poldboy -S /data/3306/mysql.sock shutdown
将my.cnf修改为3306和3307后和mysql脚本，放在/data/3306和/data/3307下
[root@mysql data]# tree
.
├── 3306
│ ├── data
│ ├── my.cnf
│ └── mysql
└── 3307
├── data
├── my.cnf
└── mysql
4 directories, 4 files五、文件权限及所属
chown -R mysql.mysql /data
find /data -type f -name "mysql" |xargs chmod 700
find /data -type f -name "mysql" |xargs ls -l六、全局路径配置
echo 'export PATH=/application/mysq/bin:$PATH' >>/etc/profile
tail -1 /etc/profile
source /etc/profile七、初始化数据库
cd /application/mysql/
./bin/mysqld --defaults-file=/data/3306/my.cnf --initialize --basedir=/application/mysql/ --datadir=/data/3306/data/ --user=mysql
./bin/mysqld --defaults-file=/data/3307/my.cnf --initialize --basedir=/application/mysql/ --datadir=/data/3307/data/ --user=mysql八、mysql启动、关闭、登录
/data/3307/mysql start
/data/3307/mysql stop
#mysql登录
mysql -S /data/3307/mysql.sock
#修改密码
mysqladmin -uroot -p'password' password '123456' -S /data/3307/mysql.sock
#远程登录多实例
mysql -uuser -p'password' -h292.168.1.23 -P 3307九、报错处理
报错1：
启动不起来，日志显示：
2019-12-12T17:51:06.643562Z 0 [ERROR] InnoDB: The Auto-extending innodb_system data file './ibdata1' is of a different size 768 pages (rounded down to MB) than specified in the .cnf file: initial 8192 pages, max 0 (relevant if non-zero) pages!
2019-12-12T17:51:06.643597Z 0 [ERROR] InnoDB: Plugin initialization aborted with error Generic error
2019-12-12T17:51:06.945987Z 0 [ERROR] Plugin 'InnoDB' init function returned error.
2019-12-12T17:51:06.946185Z 0 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2019-12-12T17:51:06.946203Z 0 [ERROR] Failed to initialize plugins.
2019-12-12T17:51:06.946214Z 0 [ERROR] Aborting解决方法：
初始化没有加配置文件重新初始化
./bin/mysqld --initialize --defaults-file=/data/3307/my.cnf --basedir=/application/mysql/ --datadir=/data/3307/data/ --user=mysql参数顺序有问题如下：报错2报错2：
2019-12-12T18:24:10.667460Z 0 [ERROR] unknown variable 'defaults-file=/data/3307/my.cnf'
2019-12-12T18:24:10.667497Z 0 [ERROR] Aborting原因见博客：https://www.cnblogs.com/jerry-rock/p/7380922.html
解决方法，修改成如下：
./bin/mysqld --defaults-file=/data/3307/my.cnf --initialize --basedir=/application/mysql/ --datadir=/data/3307/data/ --user=mysql报错3：
2019-12-12T18:22:50.814935Z 0 [ERROR] --initialize specified but the data directory has files in it. Aborting.
2019-12-12T18:22:50.814979Z 0 [ERROR] Aborting原因：/data/3307/data/ 目录有旧的初始化文件需要删除清空。
解决方法：
rm -fr /data/3307/data/*报错4：
2019-12-12T18:29:32.841614Z 0 [ERROR] unknown variable 'table_cache=64' #改为table_open_cache
2019-12-12T18:29:32.841644Z 0 [ERROR] unknown variable 'thread_concurrency=2' #需删除
2019-12-12T19:04:17.320405Z 0 [ERROR] unknown variable 'innodb_additional_mem_pool_size=4M' #需删除
2019-12-12T19:14:21.886638Z 0 [ERROR] unknown variable 'innodb_file_io_threads=4' #需删除
2019-12-12T18:29:32.841644Z 0 [ERROR] Aborting原因见博客：https://www.cnblogs.com/putihk/p/7967829.html
mysql版本5.7，我用的my.cnf配置文件中参数名字改动或删减
