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 -ivh epel-release-6-8.noarch.rpm
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2.同步时间
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[root@node1 src]# yum install -y ntp
[root@node1 src]# ntpdate 202.120.2.101
[root@node1 src]# hwclock –w
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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*
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4.安装cmake
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[root@node1 ~]# yum install -y cmake
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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
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2.创建mysql用户与组
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[root@node1 ~]# useradd mysql
[root@node1 ~]# id mysql
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 -R mysql.mysql /data/mysql/
[root@node1 ~]# chown -R mysql.mysql /data/mysql/data
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4.安装mysql
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[root@node1 ~]# cd src/
[root@node1 src]# tar xf mysql-5.5.35.tar.gz
[root@node1 src]# cd mysql-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
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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 -rf data
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2.创建多实例配置需要的目录
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[root@node1 mysql]# mkdir etc tmp run log binlogs data data2 data3 data4
[root@node1 mysql]# chown -R mysql.mysql tmp run log binlogs data data2 data3 data4
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3.提供配置文件
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[root@node1 ~]# cd src/
[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]# vim my.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 general purpose database. # The locations are default. # 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 this blank if you want to control it on slave max_binlog_size = 1024M # This is exlusively for mysqld2 # It is on 3307 with data directory /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 DNS lookups #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 for mysqld3 # It is on 3308 with data directory /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 exlusively for mysqld4
# It is on 3309 with data directory /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 the my.cnf is shared
# Here follows entries for some 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 max connections max_connections = 2 # The expiration time for logs, including binlogs expire_logs_days = 14 # Set the character as utf8 character-set-server = utf8
collation-server = utf8_unicode_ci # This is usually only needed when setting up chained replication #log-slave-updates # Enable this to make replication more resilient against server crashes and restarts # but can cause higher I/O on the server #sync_binlog = 1 # The server id, should be unique in same network server-id = 1
# Set this to force MySQL to use a particular engine/table-type for new tables # This setting can still be overridden by specifying the engine explicitly # in the CREATE TABLE statement default-storage-engine = INNODB # Enable Per Table Data for InnoDB to shrink ibdata1 innodb_file_per_table = 1 # Uncomment the following if you 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_size up to 50 - 80 % of RAM # but beware of setting memory 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
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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 -R root.root /data/mysql/etc
[root@node1 etc]# chmod 600 /data/mysql/etc/my.cnf
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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/
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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
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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
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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
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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
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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
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2.提供管理脚本
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[root@node1 mysql]# cp support-files/mysqld_multi.server init.d/
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3.简单修改一下脚本
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[root@node1 mysql]# cd init.d/
[root@node1 init.d]# vim mysqld_multi.server
#!/bin/sh # # A simple startup script for mysqld_multi by Tim Smith and Jani Tolonen. # This script assumes that my.cnf file exists either in /etc/my.cnf or # /root/.my.cnf and has groups [mysqld_multi] and [mysqldN]. See the # mysqld_multi documentation for detailed instructions. # # This script can be used as /etc/init.d/mysql.server # # Comments to support chkconfig on RedHat Linux # chkconfig: 2345 64 36 # description: A very fast and reliable SQL database engine. # # Version 1.0 #basedir=/data/mysql bindir=/data/mysql/bin
conf=/data/mysql/etc/my.cnf
export PATH=$PATH:$bindir
if test -x $bindir/mysqld_multi then mysqld_multi="$bindir/mysqld_multi";
else echo "Can't execute $bindir/mysqld_multi from dir $basedir";
exit;
ficase "$1" in 'start' )
"$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 czvf mysql-5.5.350-full.tar.gz /data/mysql/
[root@node1 data]# ll -h
总用量 128M drwx------. 2 root root 16K 8月 17 18:42 lost+found drwxr-xr-x 22 mysql mysql 4.0K 1月 6 22:08 mysql -rw-r--r-- 1 root root 128M 1月 7 00:25 mysql-5.5.350-full.tar.gz
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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
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或方法二：
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[root@node1 ~]# /data/mysql/init.d/mysqld_multi.server start 3306,3307,3308,3309
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(2).查看一下启动的实例
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[root@node1 ~]# netstat -ntulp | grep mysqld
tcp 0 0 0.0.0.0:3307 0.0.0.0:* LISTEN 31416/mysqld tcp 0 0 0.0.0.0:3308 0.0.0.0:* LISTEN 31414/mysqld tcp 0 0 0.0.0.0:3309 0.0.0.0:* LISTEN 31420/mysqld tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 31413/mysqld
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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
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或方法二：
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[root@node1 ~]# /data/mysql/init.d/mysqld_multi.server stop 3306,3307,3308,3309
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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
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 32221/mysqld
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(2).关闭一个实例
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[root@node1 ~]# /data/mysql/init.d/mysqld_multi.server stop 1
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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 -h127.0.0.1 -P3306 -p
Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 1
Server version: 5.5.35-log Source distributionCopyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | test |
+--------------------+ 4 rows in set (0.00 sec)
mysql> create database mydb1; Query OK, 1 row affected (0.00 sec)mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mydb1 | | mysql | | performance_schema | | test |
+--------------------+ 5 rows in set (0.00 sec)
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2.登录[mysqld2]
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[root@node1 ~]# /data/mysql/bin/mysql -uroot -h127.0.0.1 -P3307 -p
Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 1
Server version: 5.5.35-log Source distributionCopyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | test |
+--------------------+ 4 rows in set (0.00 sec)
mysql> create database mydb2; Query OK, 1 row affected (0.00 sec)mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mydb2 | | mysql | | performance_schema | | test |
+--------------------+ 5 rows in set (0.00 sec)
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3.登录[mysqld3]
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[root@node1 ~]# /data/mysql/bin/mysql -uroot -h127.0.0.1 -P3308 -p
Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 1
Server version: 5.5.35-log Source distributionCopyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | test |
+--------------------+ 4 rows in set (0.01 sec)
mysql> create database mydb3; Query OK, 1 row affected (0.00 sec)mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mydb3 | | mysql | | performance_schema | | test |
+--------------------+ 5 rows in set (0.00 sec)
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4.登录[mysqld4]
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[root@node1 ~]# /data/mysql/bin/mysql -uroot -h127.0.0.1 -P3309 -p
Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 1
Server version: 5.5.35-log Source distributionCopyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | test |
+--------------------+ 4 rows in set (0.01 sec)
mysql> create database mydb4; Query OK, 1 row affected (0.00 sec)mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mydb4 | | mysql | | performance_schema | | test |
+--------------------+ 5 rows in set (0.00 sec)
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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 -h127.0.0.1 -P3306 password '123456'
[root@node1 ~]# /data/mysql/bin/mysqladmin -uroot -h127.0.0.1 -P3307 password '123456'
[root@node1 ~]# /data/mysql/bin/mysqladmin -uroot -h127.0.0.1 -P3308 password '123456'
[root@node1 ~]# /data/mysql/bin/mysqladmin -uroot -h127.0.0.1 -P3309 password '123456'
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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>select Host,User,Password from user; #查看所有用户
mysql>delete from user where password="";#删除无密码账户
mysql>flush privileges; #刷新权限
mysql>select Host,User,Password from user; #确认密码为空的用户是否已全部删除
mysql>exit;
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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-h127.0.0.1选项，你是无法登录的。
最后，希望大家有所收获吧^_^……
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