一、前言

二、概述

三、环境准备

四、安装MySQL 5.5.35

五、新建支持多实例的配置文件（我这里配置的是四个实例）

六、初始化多实例数据库

七、提供管理脚本 mysqld_multi.server

八、整体备份方便后续迁移

九、管理MySQL多实例

十、登录MySQL多实例

十一、其它管理配置

十二、总结

注，测试环境 CentOS 6.4 x86_64，软件版本 MySQL 5.5.35，软件下载地址：http://dev.mysql.com/downloads/mysql/5.1.html#downloads。

1.应用场景

·采用了数据伪分布式架构的原因，而项目启动初期又不一定有那多的用户量，为此先一组物理数据库服务器，但部署多个实例，方便后续迁移；

·为规避mysql对SMP架构不支持的缺陷，使用多实例绑定处理器的办法，把不同的数据库分配到不同的实例上提供数据服务；

·一台物理数据库服务器支撑多个数据库的数据服务，为提高mysql复制的从机的恢复效率，采用多实例部署；

·已经为双主复制的mysql数据库服务器架构，想部分重要业务的数据多一份异地机房的热备份，而mysql复制暂不支持多主的复制模式，且不给用户提供服务，为有效控制成本，会考虑异地机房部署一台性能超好的物理服务器，甚至外加磁盘柜的方式，为此也会部署多实例；

·传统游戏行业的MMO/MMORPG，以及Web Game，每一个服都对应一个数据库，而可能要做很多数据查询和数据订正的工作，为减少维护而出错的概率，也可能采用多实例部署的方式，按区的概念分配数据库；

上面的应用场景介绍主要参考这篇文章：http://www.zhdba.com/mysqlops/2011/07/30/multi-mysqld/，我们这里应用主要是基于前面三种场景。下面我们来说一下要注意的问题……

2.背景/需求、注意事项

(1).背景与需求

·将所有的安装文件、配置文件、数据目录全部放存/data/mysql目录中，便于今后实现快速迁移、整体备份和快速复制；

·在一台服务器上运行四个MySQL实例，分别绑定在3306、3307、3308、3309端口上；

·四个实例都开启binlog日志，数据目录分别存放在/data/mysql/data、/data/mysql/data2、/data/mysql/data3、/data/mysql/data4

·四个实例均采用InnoDB作为默认的存储引擎，字符编码采用UTF-8；

·四个实例均采用相同的性能优化配置参数；

(2).注意事项

·在编译安装时，将数据库的配置文件my.cnf以及data目录等均指向到/data/mysql目录中；

·通过mysqld_multi的方式来管理四个不同的实例，采用相同的配置文件共享性能优化配置参数；

·在同一个配置文件中，利用[mysqld1]、[mysqld2]、[mysqld3]、[mysqld4]标签实现不同实例的差异化配置；

三、环境准备

1.安装yum源

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[root@node1 src]# wget http://mirrors.hustunique.com/epel/6/x86_64/epel-release-6-8.noarch.rpm

[root@node1 src]# rpm -ivhepel-release-6-8.noarch.rpm

2.同步时间

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[root@node1 src]# yuminstall -y ntp

[root@node1 src]# ntpdate202.120.2.101

[root@node1 src]# hwclock –w

3.安装mysql5.5依赖包

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[root@node1 ~]# yum install-y autoconf* automake* zlib* libxml* ncurses-devel* libgcrypt* libtool*openssl*

4.安装cmake

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[root@node1 ~]# yum install-y cmake

四、安装MySQL 5.5.35

1.创建安装目录与数据存放目录

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[root@node1 ~]# mkdir/data/mysql

[root@node1 ~]# mkdir/data/mysql/data

2.创建mysql用户与组

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[root@node1 ~]# useraddmysql

[root@node1 ~]# idmysql

uid=500(mysql)gid=500(mysql) 组=500(mysql)

3.授权安装目录与数据目录

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[root@node1 ~]# chown -Rmysql.mysql /data/mysql/

[root@node1 ~]# chown -R mysql.mysql/data/mysql/data

4.安装mysql

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[root@node1 ~]# cdsrc/

[root@node1 src]# tar xfmysql-5.5.35.tar.gz

[root@node1 src]# cdmysql-5.5.35

[root@node1 mysql-5.5.35]#cmake -DCMAKE_INSTALL_PREFIX=/data/mysql -DSYSCONFDIR=/data/mysql/etc -DMYSQL_DATADIR=/data/mysql/data-DMYSQL_TCP_PORT=3306 -DMYSQL_UNIX_ADDR=/tmp/mysqld.sock -DMYSQL_USER=mysql-DEXTRA_CHARSETS=all -DWITH_READLINE=1 -DWITH_SSL=system-DWITH_EMBEDDED_SERVER=1 -DENABLED_LOCAL_INFILE=1-DWITH_INNOBASE_STORAGE_ENGINE=1

[root@node1 mysql-5.5.35]#make && make install

好了，到这里我们的mysql就安装完成了，下面我们为mysql提供多实例配置文件。

五、新建支持多实例的配置文件（我这里配置的是四个实例）

1.删除默认的数据目录

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[root@node1 ~]# cd/data/mysql/

[root@node1 mysql]# rm -rfdata

2.创建多实例配置需要的目录

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[root@node1 mysql]# mkdiretc tmp run log binlogs data data2 data3 data4

[root@node1 mysql]# chown -Rmysql.mysql tmp run log binlogs data data2 data3 data4

3.提供配置文件

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[root@node1 ~]# cdsrc/

[root@node1 src]# cd mysql-5.5.35

[root@node1 mysql-5.5.35]#cp support-files/my-small.cnf /data/mysql/etc/my.cnf

[root@node1 ~]# cd/data/mysql/etc/

[root@node1 etc]# vimmy.cnf

# This server may run 4+separate instances. So we use mysqld_multi to manage their services.

[client]

default-character-set= utf8

[mysqld_multi]

mysqld=/data/mysql/bin/mysqld_safe

mysqladmin=/data/mysql/bin/mysqladmin

log=/data/mysql/log/mysqld_multi.log

user =root

#password =

# This is the generalpurpose database.

# The locations aredefault.

# They are left in [mysqld]in case the server is started normally instead of by mysqld_multi.

[mysqld1]

socket=/data/mysql/run/mysqld.sock

port = 3306

pid-file=/data/mysql/run/mysqld.pid

datadir=/data/mysql/data

lc-messages-dir=/data/mysql/share/english

# These support master -master replication

#auto-increment-increment =4

#auto-increment-offset =1 # Since it is master 1

log-bin=/data/mysql/binlogs/bin-log-mysqld1

log-bin-index=/data/mysql/binlogs/bin-log-mysqld1.index

#binlog-do-db = # Leave thisblank if you want to control it on slave

max_binlog_size =1024M

# This is exlusively formysqld2

# It is on 3307 with datadirectory /data/mysqld/data2

[mysqld2]

socket=/data/mysql/run/mysqld.sock2

port = 3307

pid-file=/data/mysql/run/mysqld.pid2

datadir=/data/mysql/data2

lc-messages-dir=/data/mysql/share/english

# Disable DNSlookups

#skip-name-resolve

# These support master -slave replication

log-bin =/data/mysql/binlogs/bin-log-mysqld2

log-bin-index=/data/mysql/binlogs/bin-log-mysqld2.index

#binlog-do-db = #Leave this blank if you want to control it on slave

max_binlog_size = 1024M

# Relay log settings

#relay-log =/data/mysql/log/relay-log-mysqld2

#relay-log-index =/data/mysql/log/relay-log-mysqld2.index

#relay-log-space-limit = 4G

# Slow query log settings

#log-slow-queries = /data/mysql/log/slow-log-mysqld2

#long_query_time = 2

#log-queries-not-using-indexes

# This is exlusively formysqld3

# It is on 3308 with datadirectory /data/mysqld/data3

[mysqld3]

socket=/data/mysql/run/mysqld.sock3

port = 3308

pid-file=/data/mysql/run/mysqld.pid3

datadir=/data/mysql/data3

lc-messages-dir=/data/mysql/share/english

#Disable DNS lookups

#skip-name-resolve

# These support master -slave replication

log-bin=/data/mysql/binlogs/bin-log-mysqld3

log-bin-index=/data/mysql/binlogs/bin-log-mysqld3.index

#binlog-do-db = #Leave this blank if you want to control it on slave

max_binlog_size =1024M

# This is exlusivelyfor mysqld4

# It is on 3309 with datadirectory /data/mysqld/data4

[mysqld4]

socket=/data/mysql/run/mysqld.sock4

port = 3309

pid-file=/data/mysql/run/mysqld.pid4

datadir=/data/mysql/data4

lc-messages-dir=/data/mysql/share/english

# Disable DNS lookups

#skip-name-resolve

# These support master -slave replication

log-bin=/data/mysql/binlogs/bin-log-mysqld4

log-bin-index=/data/mysql/binlogs/bin-log-mysqld4.index

#binlog-do-db = #Leave this blank if you want to control it on slave

max_binlog_size = 1024M

# The rest of themy.cnf is shared

# Here follows entries forsome specific programs

# The MySQL server

[mysqld]

basedir =/data/mysql

tmpdir=/data/mysql/tmp

socket=/data/mysql/run/mysqld.sock

port = 3306

pid-file=/data/mysql/run/mysqld.pid

datadir=/data/mysql/data

lc-messages-dir=/data/mysql/share/english

skip-external-locking

key_buffer_size =16K

max_allowed_packet =1M

table_open_cache =4

sort_buffer_size =64K

read_buffer_size =256K

read_rnd_buffer_size =256K

net_buffer_length =2K

thread_stack =128K

# Increase the maxconnections

max_connections =2

# The expiration time forlogs, including binlogs

expire_logs_days =14

# Set the character asutf8

character-set-server =utf8

collation-server =utf8_unicode_ci

# This is usually onlyneeded when setting up chained replication

#log-slave-updates

# Enable this to makereplication more resilient against server crashes and restarts

# but can cause higher I/Oon the server

#sync_binlog = 1

# The server id, should beunique in same network

server-id= 1

# Set this to force MySQL touse a particular engine/table-type for new tables

# This setting can still beoverridden by specifying the engine explicitly

# in the CREATE TABLEstatement

default-storage-engine =INNODB

# Enable Per Table Data forInnoDB to shrink ibdata1

innodb_file_per_table =1

# Uncomment the following ifyou are using InnoDB tables

#innodb_data_home_dir =/data/mysql/data

#innodb_data_file_path =ibdata1:10M:autoextend

#innodb_log_group_home_dir =/data/mysql/data

# You can set .._buffer_pool_sizeup to 50 - 80 % of RAM

# but beware of settingmemory usage too high

innodb_buffer_pool_size =16M

innodb_additional_mem_pool_size= 2M

# Set .._log_file_size to 25% of buffer pool size

innodb_log_file_size =5M

innodb_log_buffer_size =8M

innodb_flush_log_at_trx_commit= 1

innodb_lock_wait_timeout =50

[mysqldump]

quick

max_allowed_packet =16M

[mysql]

no-auto-rehash

[myisamchk]

key_buffer_size =8M

sort_buffer_size =8M

[mysqlhotcopy]

interactive-timeout

[mysql.server]

user = mysql

[mysqld_safe]

log-error=/data/mysql/log/mysqld.log

pid-file=/data/mysql/run/mysqld.pid

open-files-limit = 8192

注，MySQL自带了几个不同的配置文件，放置在/data/mysql/support-files目录下，分别是my-huge.cnf,my-innodb-heavy-4G.cnf,my-large.cnf,my-medium.cnf,my-small.cnf，通过名称我们可以很直观的了解到他们是针对不同的服务器配置的，本文的配置文件是来自于my-small.cnf的，因为我是在虚拟机上进行的设置；在生产环境中，我们可以通过参考my-huge.cnf或my-innodb-heavy-4G.cnf中的部分参数配置，来对服务器进行优化；

4.修改my.cnf读写权限

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[root@node1 etc]# chown -Rroot.root /data/mysql/etc

[root@node1 etc]# chmod 600/data/mysql/etc/my.cnf

好了，到这里我们的配置文件就设置完成了，下面我们来初始化一下数据库。

六、初始化多实例数据库

1.切换到mysql的安装目录

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[root@node1 ~]# cd /data/mysql/

2.初始化实例[mysqld1]

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[root@node1 mysql]#scripts/mysql_install_db --basedir=/data/mysql --datadir=/data/mysql/data--user=mysql

3.初始化实例[mysqld2]

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[root@node1 mysql]#scripts/mysql_install_db --basedir=/data/mysql --datadir=/data/mysql/data2 --user=mysql

4.初始化实例[mysqld3]

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[root@node1 mysql]#scripts/mysql_install_db --basedir=/data/mysql --datadir=/data/mysql/data3--user=mysql

5.初始化实例[mysqld4]

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[root@node1 mysql]#scripts/mysql_install_db --basedir=/data/mysql --datadir=/data/mysql/data4 --user=mysql

好了，到这里我们初始化工作就完成了，下面我们来提供一下多实例的管理脚本。

七、提供管理脚本 mysqld_multi.server

1.创建管理脚本目录

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[root@node1 mysql]# mkdir/data/mysql/init.d

2.提供管理脚本

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[root@node1 mysql]# cpsupport-files/mysqld_multi.server init.d/

3.简单修改一下脚本

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[root@node1 mysql]# cdinit.d/

[root@node1 init.d]# vimmysqld_multi.server

#!/bin/sh

#

# A simple startup scriptfor mysqld_multi by Tim Smith and Jani Tolonen.

# This script assumes thatmy.cnf file exists either in /etc/my.cnf or

# /root/.my.cnf and hasgroups [mysqld_multi] and [mysqldN]. See the

# mysqld_multi documentationfor detailed instructions.

#

# This script can be used as/etc/init.d/mysql.server

#

# Comments to supportchkconfig on RedHat Linux

# chkconfig: 2345 6436

# description: A very fastand reliable SQL database engine.

#

# Version 1.0

#

basedir=/data/mysql

bindir=/data/mysql/bin

conf=/data/mysql/etc/my.cnf

exportPATH=$PATH:$bindir

iftest-x $bindir/mysqld_multi

then

mysqld_multi="$bindir/mysqld_multi";

else

echo"Can't execute $bindir/mysqld_multi from dir$basedir";

exit;

fi

case"$1"in

'start')

"$mysqld_multi"--defaults-extra-file=$conf start $2

;;

'stop')

"$mysqld_multi"--defaults-extra-file=$conf stop $2

;;

'report')

"$mysqld_multi"--defaults-extra-file=$conf report $2

;;

'restart')

"$mysqld_multi"--defaults-extra-file=$conf stop $2

"$mysqld_multi"--defaults-extra-file=$conf start $2

;;

*)

echo"Usage: $0 {start|stop|report|restart}">&2

;;

esac

好了，到这里我们所有的配置就全部完成了，下面我们打包备份一下。

八、整体备份方便后续迁移

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[root@node1 ~]# cd/data/

[root@node1 data]# tar czvfmysql-5.5.350-full.tar.gz /data/mysql/

[root@node1 data]# ll-h

总用量 128M

drwx------. 2root root 16K 8月 17 18:42 lost+found

drwxr-xr-x 22 mysqlmysql 4.0K 1月 6 22:08 mysql

-rw-r--r-- 1root root 128M 1月 7 00:25 mysql-5.5.350-full.tar.gz

注，备份完成后，直接将mysql-5.5.350-full.tar.gz拿到其他服务器上，解压后便可以直接启用。嘿嘿，方便吧……

九、管理MySQL多实例

1.同时启动四个mysql实例

(1).方法一：

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[root@node1 ~]#/data/mysql/init.d/mysqld_multi.server start 1,2,3,4

或方法二：

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[root@node1 ~]#/data/mysql/init.d/mysqld_multi.server start 3306,3307,3308,3309

(2).查看一下启动的实例

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[root@node1 ~]# netstat-ntulp | grep mysqld

tcp0 00.0.0.0:33070.0.0.0:*LISTEN 31416/mysqld

tcp0 00.0.0.0:33080.0.0.0:*LISTEN 31414/mysqld

tcp0 00.0.0.0:33090.0.0.0:*LISTEN 31420/mysqld

tcp0 0 0.0.0.0:33060.0.0.0:*LISTEN 31413/mysqld

2.同时关闭四个mysql实例

(1).方法一：

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[root@node1 ~]#/data/mysql/init.d/mysqld_multi.server stop 1,2,3,4

或方法二：

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[root@node1 ~]#/data/mysql/init.d/mysqld_multi.server stop 3306,3307,3308,3309

3.单独启动或关闭mysql实例

(1).启动一个实例

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[root@node1 ~]#/data/mysql/init.d/mysqld_multi.server start 1

[root@node1 ~]# netstat-ntulp | grep mysqld

tcp0 00.0.0.0:33060.0.0.0:*LISTEN 32221/mysqld

(2).关闭一个实例

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[root@node1 ~]#/data/mysql/init.d/mysqld_multi.server stop 1

注，启动或关闭两个或者三个实例方法的上面相同这里就不再演示。

十、登录MySQL多实例

注，我们同时启动四个实例，下面我们来演示一下怎么分别登录这四个实例。为了演示四个实例的区别，我们分别在四个实例中创建mydb1、mydb2、mydb3、mydb4。

1.登录[mysqld1]

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[root@node1 ~]#/data/mysql/bin/mysql -uroot -h227.0.0.1 -P3306 -p

Enterpassword:

Welcome to the MySQLmonitor. Commands end with ; or \g.

Your MySQLconnectionidis 1

Server version: 5.5.35-logSource distribution

Copyright (c) 2000, 2013,Oracle and/orits affiliates. All rightsreserved.

Oracle is a registeredtrademark of Oracle Corporation and/orits

affiliates. Other names maybe trademarks of their respective

owners.

Type'help;'or'\h'forhelp.Type'\c'toclearthe current input statement.

mysql> showdatabases;

+--------------------+

|Database|

+--------------------+

| information_schema|

|mysql|

| performance_schema|

|test|

+--------------------+

4 rowsinset(0.00 sec)

mysql> create databasemydb1;

Query OK, 1 row affected(0.00 sec)

mysql> showdatabases;

+--------------------+

|Database|

+--------------------+

| information_schema|

|mydb1|

|mysql|

| performance_schema|

|test|

+--------------------+

5 rowsinset(0.00 sec)

2.登录[mysqld2]

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[root@node1 ~]#/data/mysql/bin/mysql -uroot -h227.0.0.1 -P3307 -p

Enterpassword:

Welcome to the MySQLmonitor. Commands end with ; or \g.

Your MySQLconnectionidis 1

Server version: 5.5.35-logSource distribution

Copyright (c) 2000, 2013,Oracle and/orits affiliates. All rightsreserved.

Oracle is a registeredtrademark of Oracle Corporation and/orits

affiliates. Other names maybe trademarks of their respective

owners.

Type'help;'or'\h'forhelp.Type'\c'toclearthe current input statement.

mysql> showdatabases;

+--------------------+

|Database|

+--------------------+

| information_schema|

|mysql|

| performance_schema|

|test|

+--------------------+

4 rowsinset(0.00 sec)

mysql> create databasemydb2;

Query OK, 1 row affected(0.00 sec)

mysql> showdatabases;

+--------------------+

|Database|

+--------------------+

| information_schema|

|mydb2|

|mysql|

| performance_schema|

|test|

+--------------------+

5 rowsinset(0.00 sec)

3.登录[mysqld3]

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[root@node1 ~]#/data/mysql/bin/mysql -uroot -h227.0.0.1 -P3308 -p

Enterpassword:

Welcome to the MySQLmonitor. Commands end with ; or \g.

Your MySQLconnectionidis 1

Server version: 5.5.35-logSource distribution

Copyright (c) 2000, 2013,Oracle and/orits affiliates. All rights reserved.

Oracle is a registeredtrademark of Oracle Corporation and/orits

affiliates. Other names maybe trademarks of their respective

owners.

Type'help;'or'\h'forhelp.Type'\c'toclearthe current input statement.

mysql> showdatabases;

+--------------------+

|Database|

+--------------------+

| information_schema|

|mysql|

| performance_schema|

|test|

+--------------------+

4 rowsinset(0.01 sec)

mysql> create databasemydb3;

Query OK, 1 row affected(0.00 sec)

mysql> showdatabases;

+--------------------+

|Database|

+--------------------+

| information_schema|

|mydb3|

|mysql|

| performance_schema|

|test|

+--------------------+

5 rowsinset(0.00 sec)

4.登录[mysqld4]

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[root@node1 ~]#/data/mysql/bin/mysql -uroot -h227.0.0.1 -P3309 -p

Enterpassword:

Welcome to the MySQLmonitor. Commands end with ; or \g.

Your MySQLconnectionidis 1

Server version: 5.5.35-logSource distribution

Copyright (c) 2000, 2013,Oracle and/orits affiliates. All rightsreserved.

Oracle is a registeredtrademark of Oracle Corporation and/orits

affiliates. Other names maybe trademarks of their respective

owners.

Type'help;'or'\h'forhelp.Type'\c'toclearthe current input statement.

mysql> showdatabases;

+--------------------+

|Database|

+--------------------+

| information_schema|

|mysql|

| performance_schema|

|test|

+--------------------+

4 rowsinset(0.01 sec)

mysql> create databasemydb4;

Query OK, 1 row affected(0.00 sec)

mysql> show databases;

+--------------------+

|Database|

+--------------------+

| information_schema|

|mydb4|

|mysql|

| performance_schema|

|test|

+--------------------+

5 rowsinset(0.00 sec)

好了，我们的MySQL多实例登录就演示到这里了，下面我们来设置一下mysql的root密码。

十一、其它管理配置

1.为mysql的root用户创建密码

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[root@node1 ~]#/data/mysql/bin/mysqladmin -uroot -h227.0.0.1 -P3306 password '123456'

[root@node1 ~]#/data/mysql/bin/mysqladmin -uroot -h227.0.0.1 -P3307 password '123456'

[root@node1 ~]#/data/mysql/bin/mysqladmin -uroot -h227.0.0.1 -P3308 password '123456'

[root@node1 ~]#/data/mysql/bin/mysqladmin -uroot -h227.0.0.1 -P3309 password '123456'

2.删除匿名连接的空密码帐号

注，分别登录实例[mysqld1]、[mysqld2]、[mysqld3]、[mysqld4]，执行以下命令：

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mysql>use mysql;#选择系统数据库mysql

mysql>selectHost,User,Password from user;#查看所有用户

mysql>delete from userwhere password="";#删除无密码账户

mysql>flushprivileges;#刷新权限

mysql>selectHost,User,Password from user;#确认密码为空的用户是否已全部删除

mysql>exit;

十二、总结

1.采用源码编译安装MySQL，可能在第一次会花费较多的时间，但却是非常值得的，因为我们可以自己组织所有MySQL相关文件的位置；并且经过源码编译安装后的MySQL，可以直接复制到其它服务器上运行，大大方便了我们以后的迁移、备份和新服务器的配置。

2.本文中仅仅用了四个实例[mysqld1]、[mysqld2]、[mysqld3]、[mysqld4]来举例，实际上我们可以通过这样的方式，实现[mysqld5]、[mysqld6]...等更多的实例，前提是你的服务器硬件配置得根得 上，但是一般我们这边不会超过6个实例。

3.在单机运行多实例的情况下，切忌不要使用 mysql -hlocalhost 或 直接忽略-h参数登录服务器，这应该算是MySQL的一个bug，就是如果使用localhost或忽略-h参数，而不是指定127.0.0.1的话，即使选择的端口是3307，还是会登陆到3306中去，因此应尽量避免这种混乱的产生，统一用127.0.0.1绑定端口或采用socket来登录，在mysql5.5中你不指定-h227.0.0.1选项，你是无法登录的。

最后，希望大家有所收获吧^_^……