MySQL 5.5.x 单机多实例配置实践

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背景/需求：

在一台服务器上通过源码编译安装一个版本为5.5以上的MySQL数据库；
将所有配置文件与数据等均存放在/opt/mysql，便于今后实现快速迁移、整体备份和快速复制；
在同一个MySQL中运行两个实例，一个绑定在端口3306，另一个绑定在端口3307；
绑定在3306端口的实例，不开启binlog，数据存放在/opt/mysql/data；
绑定在3307端口的实例，开启binlog，数据存放在/opt/mysql/data2；
两个实例均采用InnoDB作为默认的存储引擎，字符编码采用UTF-8；
两个实例均采用相同的性能优化配置参数；

实践/方案：

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/opt/mysql目录；
通过mysqld_multi的方式来管理两个不同的实例，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]与[mysqld2]标签实现不同实例的差异化配置；

配置步骤：

一、编译安装MySQL
1.安装cmake
MySQL从5.5版本开始，通过./configure进行编译配置方式已经被取消，取而代之的是cmake工具。
因此，我们首先要在系统中源码编译安装cmake工具。
# wget http://www.cmake.org/files/v2.8/cmake-2.8.4.tar.gz

# tar zxvf cmake-2.8.4.tar.gz

# cd cmake-2.8.4

# ./configure

# make
# make install

2.确保以下所需系统软件包已经被安装

通过 rpm -qa | grep name 的方式验证以下软件包是否已全部安装。

gcc* gcc-c++* autoconf* automake* zlib* libxml* ncurses-devel* libgcrypt* libtool*

如果缺少相关的软件包，可通过yum -y install 的方式在线安装，或直接从系统安装光盘中找到并通过rpm -ivh 的方式安装。

3. 安装前的系统设置

建立mysql安装目录及数据存放目录
# mkdir /opt/mysql
# mkdir /opt/mysql/data

创建用户和用户组

# groupadd mysql
# useradd -g mysql mysql

赋予数据存放目录权限

# chown mysql:mysql -R /opt/mysql/data

4.开始编译安装 MySQL

通过http://www.mysql.com/downloads/mysql官方网址或国内的sohu镜像下载软件包，如目前最新的MySQL 5.5.20。
# wget http://mirrors.sohu.com/mysql/MySQL-5.5/mysql-5.5.20.tar.gz

# tar zxvf mysql-5.5.20.tar.gz

# cd mysql-5.5.20

# cmake -DCMAKE_INSTALL_PREFIX=/opt/mysql \
-DSYSCONFDIR=/opt/mysql/etc \
-DMYSQL_DATADIR=/opt/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

# make

# make install

在make与make install的时候可以看到进度百分比，感觉这一点要比configure方式要好。

二、创建支持多实例的配置文件

进入MySQL主目录
# cd /opt/mysql/

删除默认的data目录

# rm -rf data

创建需要的目录

# mkdir etc tmp run log binlogs data data2
# chown -R mysql:mysql tmp run log binlogs data data2

创建my.cnf配置文件

# vim etc/my.cnf

 
001 ## This server may run 2+ separate instances
002 ## So we use mysqld_multi to manage their services
003 [mysqld_multi]
004 mysqld = /opt/mysql/bin/mysqld_safe
005 mysqladmin = /opt/mysql/bin/mysqladmin
006 log = /opt/mysql/log/mysqld_multi.log
007 user = root ## Used for stopping the server via mysqladmin
008 #password = 
009   
010 ## This is the general purpose database
011 ## The locations are default
012 # They are left in [mysqld] in case the server is started normally instead of by mysqld_multi
013 [mysqld1]
014 socket = /opt/mysql/run/mysqld.sock
015 port = 3306
016 pid-file = /opt/mysql/run/mysqld.pid
017 datadir = /opt/mysql/data
018 lc-messages-dir = /opt/mysql/share/english
019   
020 ## These support master - master replication
021 #auto-increment-increment = 4
022 #auto-increment-offset = 1  ## Since it is master 1
023 #log-bin = /opt/mysql/binlogs/bin-log-mysqld1
024 #log-bin-index = /opt/mysql/binlogs/bin-log-mysqld1.index
025 #binlog-do-db = ## Leave this blank if you want to control it on slave
026 #max_binlog_size = 1024M
027   
028 ## This is exlusively for mysqld2
029 ## It is on 3307 with data directory /opt/mysqld/data2
030 [mysqld2]
031 socket = /opt/mysql/run/mysqld.sock2
032 port = 3307
033 pid-file = /opt/mysql/run/mysqld.pid2
034 datadir = /opt/mysql/data2
035 lc-messages-dir = /opt/mysql/share/english
036   
037 ## Disable DNS lookups
038 #skip-name-resolve
039   
040 ## These support master - slave replication
041 log-bin = /opt/mysql/binlogs/bin-log-mysqld2
042 log-bin-index = /opt/mysql/binlogs/bin-log-mysqld2.index
043 #binlog-do-db =  ## Leave this blank if you want to control it on slave
044 max_binlog_size = 1024M
045   
046 ## Relay log settings
047 #relay-log = /opt/mysql/log/relay-log-mysqld2
048 #relay-log-index = /opt/mysql/log/relay-log-mysqld2.index
049 #relay-log-space-limit = 4G
050   
051 ## Slow query log settings
052 #log-slow-queries = /opt/mysql/log/slow-log-mysqld2
053 #long_query_time = 2
054 #log-queries-not-using-indexes
055   
056 ## The rest of the my.cnf is shared
057 ## Here follows entries for some specific programs
058 ## The MySQL server
059 [mysqld]
060 basedir = /opt/mysql
061 tmpdir = /opt/mysql/tmp
062 socket = /opt/mysql/run/mysqld.sock
063 port = 3306
064 pid-file = /opt/mysql/run/mysqld.pid
065 datadir = /opt/mysql/data
066 lc-messages-dir = /opt/mysql/share/english
067   
068 skip-external-locking
069 key_buffer_size = 16K
070 max_allowed_packet = 1M
071 table_open_cache = 4
072 sort_buffer_size = 64K
073 read_buffer_size = 256K
074 read_rnd_buffer_size = 256K
075 net_buffer_length = 2K
076 thread_stack = 128K
077   
078 ## Increase the max connections
079 max_connections = 200
080   
081 ## The expiration time for logs, including binlogs
082 expire_logs_days = 14
083   
084 ## Set the character as utf8
085 character-set-server = utf8
086 collation-server = utf8_unicode_ci
087   
088 ## This is usually only needed when setting up chained replication
089 #log-slave-updates
090   
091 ## Enable this to make replication more resilient against server crashes and restarts
092 ## but can cause higher I/O on the server
093 #sync_binlog = 1
094   
095 ## The server id, should be unique in same network
096 server-id = 1
097   
098 ## Set this to force MySQL to use a particular engine/table-type for new tables
099 ## This setting can still be overridden by specifying the engine explicitly
100 ## in the CREATE TABLE statement
101 default-storage-engine = INNODB
102   
103 ## Uncomment the following if you are using InnoDB tables
104 #innodb_data_home_dir = /opt/mysql/data
105 #innodb_data_file_path = ibdata1:10M:autoextend
106 #innodb_log_group_home_dir = /opt/mysql/data
107 ## You can set .._buffer_pool_size up to 50 - 80 % of RAM
108 ## but beware of setting memory usage too high
109 innodb_buffer_pool_size = 16M
110 innodb_additional_mem_pool_size = 2M
111 ## Set .._log_file_size to 25 % of buffer pool size
112 innodb_log_file_size = 5M
113 innodb_log_buffer_size = 8M
114 innodb_flush_log_at_trx_commit = 1
115 innodb_lock_wait_timeout = 50
116   
117 [mysqldump]
118 quick
119 max_allowed_packet = 16M
120   
121 [mysql]
122 no-auto-rehash
123   
124 [myisamchk]
125 key_buffer_size = 8M
126 sort_buffer_size = 8M
127   
128 [mysqlhotcopy]
129 interactive-timeout
130   
131 [mysql.server]
132 user = mysql
133   
134 [mysqld_safe]
135 log-error = /opt/mysql/log/mysqld.log
136 pid-file = /opt/mysql/run/mysqld.pid
137 open-files-limit = 8192
138   
139 [client]
140 default-character-set = utf8

修改my.cnf读写权限，避免普通用户获取到MySQL密码
# chown -R root:root /opt/mysql/etc
# chmod 600 /opt/mysql/etc/my.cnf

三、初始化数据库

切换到mysql用户
# su - mysql

进入MySQL主目录

# cd /opt/mysql/

初始化实例[mysqld1]

# scripts/mysql_install_db --basedir=/opt/mysql --user=mysql --datadir=/opt/mysql/data/

初始化实例[mysqld2]

# scripts/mysql_install_db --basedir=/opt/mysql --user=mysql --datadir=/opt/mysql/data2/

返回到root

# exit

创建mysqld_multi.server脚本

# cp support-files/mysqld_multi.server /opt/mysql/init.d/

# vim /opt/mysql/init.d/mysqld_multi.server

 
01 #!/bin/sh
02 #
03 # A simple startup script for mysqld_multi by Tim Smith and Jani Tolonen.
04 # This script assumes that my.cnf file exists either in /etc/my.cnf or
05 # /root/.my.cnf and has groups [mysqld_multi] and [mysqldN]. See the
06 # mysqld_multi documentation for detailed instructions.
07 #
08 # This script can be used as /etc/init.d/mysql.server
09 #
10 # Comments to support chkconfig on RedHat Linux
11 # chkconfig: 2345 64 36
12 # description: A very fast and reliable SQL database engine.
13 #
14 # Version 1.0
15 #
16 basedir=/opt/mysql
17 bindir=/opt/mysql/bin
18   
19 conf=/opt/mysql/etc/my.cnf
20 export PATH=$PATH:$bindir
21   
22 if test -x $bindir/mysqld_multi
23 then
24   mysqld_multi="$bindir/mysqld_multi";
25 else
26   echo "Can't execute $bindir/mysqld_multi from dir $basedir";
27   exit;
28 fi
29   
30 case "$1" in
31     'start' )
32         "$mysqld_multi" --defaults-extra-file=$conf start $2
33         ;;
34     'stop' )
35         "$mysqld_multi" --defaults-extra-file=$conf stop $2
36         ;;
37     'report' )
38         "$mysqld_multi" --defaults-extra-file=$conf report $2
39         ;;
40     'restart' )
41         "$mysqld_multi" --defaults-extra-file=$conf stop $2
42         "$mysqld_multi" --defaults-extra-file=$conf start $2
43         ;;
44     *)
45         echo "Usage: $0 {start|stop|report|restart}" >&2
46         ;;
47 esac

四、整体备份MySQL

# cd /opt/
# tar czvf mysql_5.5.20_full.tar.gz mysql/

备份完成后，直接将mysql_5.5.20_full.tar.gz拿到其他服务器上，解压后便可以直接启用。

五、管理MySQL实例

同时 启动/关闭 实例 [mysqld1] 与 [mysqld2]：
# /opt/mysql/init.d/mysqld_multi.server start 1,2

然后，可以看到两个MySQL实例都已经成功的启动了。

# netstat -lntp | grep mysqld

 
1 tcp  0  0  0.0.0.0:3306  0.0.0.0:*  LISTEN 2850/mysqld
2 tcp  0  0  0.0.0.0:3307  0.0.0.0:*  LISTEN 2946/mysqld

同时 关闭 实例 [mysqld1] 与 [mysqld2]：

# /opt/mysql/init.d/mysqld_multi.server stop 1,2

仅 启动/关闭 实例[mysqld1]：

# /opt/mysql/init.d/mysqld_multi.server start 1
# /opt/mysql/init.d/mysqld_multi.server stop 1

六、登陆MySQL实例

在启动了实例[mysqld1]与[mysqld2]后，通过以下方式登陆不同的实例：

登陆[mysqld1]：

# /opt/mysql/bin/mysql -uroot -h127.0.0.1 -P3306 -p

登陆[mysqld2]：

# /opt/mysql/bin/mysql -uroot -h127.0.0.1 -P3307 -p

七、其他初始化设置

1. 为MySQL的root帐户设置初始密码
# /opt/mysql/bin/mysqladmin -u root -h127.0.0.1 -P3306 password 'new-password'
# /opt/mysql/bin/mysqladmin -u root -h127.0.0.1 -P3307 password 'new-password'

2. 修改my.cnf配置文件中MySQL的root账户密码

# vim /opt/mysql/etc/my.cnf

 
1 user = root ## Used for stopping the server via mysqladmin
2 password = new-password

3. 删除匿名连接的空密码帐号

分别登陆实例[mysqld1]与[mysqld2]，执行以下命令：
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="";
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;

八、经验总结

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，大大方便了我们今后的迁移、备份和新服务器的配置；

2.本文中仅仅用了两个实例[mysqld1]与[mysqld2]来举例，实际上我们可以通过这样的方式，实现[mysqld3],[mysqld4],[mysqld5]...等更多的实例；

3.MySQL自带了几个不同的配置文件，放置在/opt/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，本文中仅有的一点关于InnoDB的配置，是取自于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.关于MySQL缓存参数的优化，主要用于提升I/O能力，可以参考这里：

5.在单机运行多实例的情况下，切忌使用 mysql -hlocalhost 或 直接忽略-h参数 登陆服务器，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 来登陆；