linux(centOs)下memcached安装

　　1、libevent安装。为啥先安装它？因为不先装，memcached这座房子就没打地基：

yum install libevent-devel

　　敲回车后出现：

Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
base                                                                                                        | 3.6 kB  ::
epel                                                                                                        | 4.7 kB  ::
extras                                                                                                      | 3.4 kB  ::
updates                                                                                                     | 3.4 kB  ::
(/): epel/x86_64/updateinfo                                                                               |  kB  ::
(/): updates//x86_64/primary_db                                                                          | 2.5 MB  ::
(/): epel/x86_64/primary_db                                                                               | 6.6 MB  ::
Resolving Dependencies
--> Running transaction check
---> Package libevent-devel.x86_64 :2.0.-.el7 will be installed
--> Processing Dependency: libevent = 2.0.-.el7 for package: libevent-devel-2.0.-.el7.x86_64
--> Processing Dependency: libevent_pthreads-2.0.so.()(64bit) for package: libevent-devel-2.0.-.el7.x86_64
--> Processing Dependency: libevent_openssl-2.0.so.()(64bit) for package: libevent-devel-2.0.-.el7.x86_64
--> Processing Dependency: libevent_extra-2.0.so.()(64bit) for package: libevent-devel-2.0.-.el7.x86_64
--> Processing Dependency: libevent_core-2.0.so.()(64bit) for package: libevent-devel-2.0.-.el7.x86_64
--> Processing Dependency: libevent-2.0.so.()(64bit) for package: libevent-devel-2.0.-.el7.x86_64
--> Running transaction check
---> Package libevent.x86_64 :2.0.-.el7 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

===================================================================================================================================
 Package                             Arch                        Version                           Repository                 Size
===================================================================================================================================
Installing:
 libevent-devel                      x86_64                      2.0.-.el7                      base                        k
Installing for dependencies:
 libevent                            x86_64                      2.0.-.el7                      base                       k

Transaction Summary
===================================================================================================================================
Install   Package (+ Dependent package)

Total download size:  k
Installed size: 1.1 M
Is this ok [y/d/N]: y
Downloading packages:
(/): libevent-devel-2.0.-.el7.x86_64.rpm                                                               |   kB  ::
(/): libevent-2.0.-.el7.x86_64.rpm                                                                     |  kB  ::
-----------------------------------------------------------------------------------------------------------------------------------
Total                                                                                              3.5 MB/s |  kB  ::
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : libevent-2.0.-.el7.x86_64                                                                                    /
  Installing : libevent-devel-2.0.-.el7.x86_64                                                                              /
  Verifying  : libevent-devel-2.0.-.el7.x86_64                                                                              /
  Verifying  : libevent-2.0.-.el7.x86_64                                                                                    / 

Installed:
  libevent-devel.x86_64 :2.0.-.el7                                                                                             

Dependency Installed:
  libevent.x86_64 :2.0.-.el7                                                                                                   

Complete!

　　我们可以看到它自动把libevent-devel和libevent两个包一起安装好了。我们可以到安装包下看一看：

ls /usr/lib64 | grep libevent
libevent-2.0.so.5
libevent-2.0.so.5.1.9
libevent_core-2.0.so.5
libevent_core-2.0.so.5.1.9
libevent_core.so
libevent_extra-2.0.so.5
libevent_extra-2.0.so.5.1.9
libevent_extra.so
libevent_openssl-2.0.so.5
libevent_openssl-2.0.so.5.1.9
libevent_openssl.so
libevent_pthreads-2.0.so.5
libevent_pthreads-2.0.so.5.1.9
libevent_pthreads.so
libevent.so

　　2、安装memcached：

yum install memcached

　　敲完回车后：

Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Resolving Dependencies
--> Running transaction check
---> Package memcached.x86_64 :1.4.-.el7_3. will be installed
--> Finished Dependency Resolution

Dependencies Resolved

===================================================================================================================================
 Package                        Arch                        Version                                Repository                 Size
===================================================================================================================================
Installing:
 memcached                      x86_64                      1.4.-.el7_3.                      base                        k

Transaction Summary
===================================================================================================================================
Install   Package

Total download size:  k
Installed size:  k
Is this ok [y/d/N]: y
Downloading packages:
memcached-1.4.-.el7_3..x86_64.rpm                                                                      |   kB  ::
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : memcached-1.4.-.el7_3..x86_64                                                                              /
  Verifying  : memcached-1.4.-.el7_3..x86_64                                                                              / 

Installed:
  memcached.x86_64 :1.4.-.el7_3.                                                                                             

Complete!

　　3、去官方网站（http://memcached.org）下载memcached最新版本的源码包：

wget http://memcached.org/latest

　　敲完回车后：

---- ::--  http://memcached.org/latest
Resolving memcached.org (memcached.org)... 107.170.231.145
Connecting to memcached.org (memcached.org)|107.170.231.145|:... connected.
HTTP request sent, awaiting response...  Moved Temporarily
Location: https://www.memcached.org/files/memcached-1.5.12.tar.gz [following]
---- ::--  https://www.memcached.org/files/memcached-1.5.12.tar.gz
Resolving www.memcached.org (www.memcached.org)... 107.170.231.145
Connecting to www.memcached.org (www.memcached.org)|107.170.231.145|:... connected.
HTTP request sent, awaiting response...  OK
Length:  (447K) [application/octet-stream]
Saving to: 鈥榣atest鈥

%[=========================================================================================>] ,      153KB/s   in .9s   

-- :: ( KB/s) - 鈥榣atest鈥saved [/]

　　我们看到下载的最新源码包叫memcached-1.5.12.tar.gz，但wget命令却把包名叫成了latest，把下载包的名称改回去

mv latest memcached-1.5..tar.gz

　　然后解压、配置、编译和安装

tar -zxvf memcached-1.5..tar.gz
cd memcached-1.5.12
 ./configure --prefix=/usr/local/memcached
make && make test
sudo make install

　　此时已大功告成，接下来启动memcached：

/usr/local/memcached/bin/memcached -p  -m 64m -u root -d

　　这里以root用户、端口号11211、并分配了64兆内存将memcached作为守护进程在后台启动了，可以看下进程：

ps -ef | grep memcached
root             : ?        :: /usr/local/memcached/bin/memcached -p  -m 64m -u root -d

　　最后连上memcached试一把：

telnet 127.0.0.1
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
set foo
hello world
STORED
get foo
VALUE foo
hello world
END