linux下使用yum安装mysql,memcached

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 一 安装mysql

1. 查看有没有安装包：yum list mysql*或者rpm -qa | grep mysql*

2. 安装mysql客户端:

1) yum install mysql

2) 安装mysql 服务器端;

3) yum install mysql-server

4) yum install mysql-devel

2、启动&&停止

1) 数据库字符集设置,修改mysql配置文件/etc/my.cnf中加入default-character-set=utf8

2) 启动mysql服务：service mysqld start或者/etc/init.d/mysqld start

3) 开机启动：chkconfig -add mysqld，查看开机启动设置是否成功chkconfig --list | grep mysql*

4) 停止：service mysqld stop

3、登录

1) 创建root管理员：mysqladmin -u root password 123456

2) 登录：mysql -u root -p输入密码即可。

3) 忘记密码：service mysqld stop

#mysqld_safe --user=root --skip-grant-tables

#mysql -u root

>use mysql

>update user set password=password("new_pass") where user="root";

>flush privileges;  

4、远程访问

1)开放防火墙的端口号

2) mysql增加权限：mysql库中的user表新增一条记录host为“%”，user为“root”，或者将host为localhost的user改为host是"%"

5. 当service mysql start启动服务时，如果遇到“mysql: unrecognized service”，可以按以下步骤来执行：

1) rpm -q mysql查看mysql是否安装成功

2) 试用/etc/rc.d/init.d/mysqld start 看是否可以启动

3) 如果按上面步骤可启动，执行 chmod 755 /etc/rc.d/init.d/mysqld 修改权限

4) 再运行service mysql start

5) 可以设置为开机启动chkconfig mysqld on

二  安装memcached

1. memcached是基于libevent的事件处理，所以安装memcached时先要安装libevent库，首先yum list libevent-devel看看是否已有libevent-devel，若无则yum -y install libevent libevent-devel;

2. 获取安装包：

1）wget http://memcached.googlecode.com/files/memcached-1.4.4.tar.gz

2）tar -zxvf memcached-1.4.4.tar.gz

3）cd  memcached-1.4.4

4）./configure

5）make && make install

3.memcached启动：

以daemon方式启动：/usr/local/bin/memcached -u nobody -p 11211 -m 64 -c 128 -d

 

tips:memcached常用参数：（/usr/local/bin/memcached -h）

-p <num>      TCP port number to listen on (default: 11211)

-U <num>      UDP port number to listen on (default: 11211, 0 is off)

-l <ip_addr>  interface to listen on (default: INADDR_ANY, all addresses)

-d            run as a daemon

-u <username> assume identity of <username> (only when run as root)

-m <num>      max memory to use for items in megabytes (default: 64 MB)

-c <num>      max simultaneous connections (default: 1024)

-P <file>     save PID in <file>, only used with -d option

 

-f <factor>   chunk size growth factor (default: 1.25)

 

tips:查看安装目录：首先rpm -qa | grep 查看到名称，再rmp -ql即可查到安装目录

4. 利用telnet查操作memcache验证是否安装成功：

telnet host_ip port

set 

//保存
set good 32 0 10
helloworld
STORED

//取回
gets good
VALUE good 32 10 10
helloworld
END

//替换
replace good 32 0 10
worldhello
STORED
get good
VALUE good 32 10
worldhello
END

//尾部添加
append good 32 0 5
after
STORED
get good
VALUE good 32 15
worldhelloafter
END

//头部添加
prepend good 32 0 6
before
STORED
get good
VALUE good 32 21
beforeworldhelloafter
END

//删除
delete good
DELETED
get good
END

delete good
NOT_FOUND

cas good 32 0 10 hel
helloworld
EXISTS

gets good
VALUE good 32 10 10
helloworld
END

cas bad 32 0 10 good
worldhello
NOT_FOUND

//统计
stats items
STAT items:1:number 1
STAT items:1:age 24
STAT items:1:evicted 0
STAT items:1:outofmemory 0
END

stats sizes
96 1
END

stats slabs
STAT 1:chunk_size 88
STAT 1:chunks_per_page 11915
STAT 1:total_pages 1
STAT 1:total_chunks 11915
STAT 1:used_chunks 11914
STAT 1:free_chunks 1
STAT 1:free_chunks_end 11913
STAT 2:chunk_size 112
STAT 2:chunks_per_page 9362
STAT 2:total_pages 1
STAT 2:total_chunks 9362
STAT 2:used_chunks 9361
STAT 2:free_chunks 1
STAT 2:free_chunks_end 9361
STAT 5:chunk_size 232
STAT 5:chunks_per_page 4519
STAT 5:total_pages 1
STAT 5:total_chunks 4519
STAT 5:used_chunks 4518
STAT 5:free_chunks 1
STAT 5:free_chunks_end 4518
STAT active_slabs 3
STAT total_malloced 3145472
END

stats items
STAT items:1:number 1
STAT items:1:age 1768
STAT items:1:evicted 0
STAT items:1:outofmemory 0
END

stats
STAT pid 18261
STAT uptime 528593
STAT time 1237277383
STAT version 1.2.6
STAT pointer_size 32
STAT rusage_user 0.004999
STAT rusage_system 0.015997
STAT curr_items 1
STAT total_items 2
STAT bytes 66
STAT curr_connections 2
STAT total_connections 13
STAT connection_structures 3
STAT cmd_get 11
STAT cmd_set 8
STAT get_hits 2
STAT get_misses 9
STAT evictions 0
STAT bytes_read 1342
STAT bytes_written 8752
STAT limit_maxbytes 134217728
STAT threads 1
END

使用usr/bin/perl /root/memcached-1.2.6/scripts/memcached-tool localhost:11211
output
# Item_Size   Max_age 1MB_pages Count   Full?
1      88 B     1531 s       1       1      no
2     112 B        0 s       1       0      no
5     232 B        0 s       1       0      no

# slab class编号 
Item_Size Chunk大小 
Max_age LRU内最旧的记录的生存时间 
1MB_pages 分配给Slab的页数 
Count Slab内的记录数 
Full? Slab内是否含有空闲chunk