# yum install memcached # rpm -ql memcached /etc/sysconfig/memcached /usr/bin/memcached /usr/bin/memcached-tool /usr/lib/systemd/system/memcached.service /usr/share/doc/memcached-1.4.15 /usr/share/doc/memcached-1.4.15/AUTHORS /usr/share/doc/memcached-1.4.15/ConTRIBUTORS /usr/share/doc/memcached-1.4.15/COPYING /usr/share/doc/memcached-1.4.15/ChangeLog /usr/share/doc/memcached-1.4.15/NEWS /usr/share/doc/memcached-1.4.15/README.md /usr/share/doc/memcached-1.4.15/protocol.txt /usr/share/doc/memcached-1.4.15/readme.txt /usr/share/doc/memcached-1.4.15/threads.txt /usr/share/man/man1/memcached-tool.1.gz /usr/share/man/man1/memcached.1.gz # cat /usr/lib/systemd/system/memcached.service [Service] Type=simple EnvironmentFile=-/etc/sysconfig/memcached ExecStart=/usr/bin/memcached -u USER -pPORT -m CACHESIZE -cMAXCONN $OPTIONS # cat /etc/sysconfig/memcached PORT="11211" USER="memcached" MAXCONN="1024" CACHESIZE="64" OPTIONS="" 前台显示看看效果 # memcached -u memcached -p 11211 -f 1.25 -vv # systemctl start memcached
修改memcached运行参数，可以使用下面的选项修改/etc/sysconfig/memcached文件
-u username memcached运行的用户身份，必须普通用户
-p 绑定的端口，默认11211
-m num 最大内存，单位MB，默认64MB
-c num 最大连接数，缺省1024
-d 守护进程方式运行
-f 增长因子Growth Factor，默认1.25
-v 详细信息，-vv能看到详细信息
-M 内存耗尽，不许LRU
-U 设置UDP监听端口，0表示禁用UDP
# yum list all | grep memcached memcached.x86_64 1.4.15-10.el7_3.1 @base libmemcached.i686 1.0.16-5.el7 base libmemcached.x86_64 1.0.16-5.el7 base libmemcached-devel.i686 1.0.16-5.el7 base libmemcached-devel.x86_64 1.0.16-5.el7 base memcached-devel.i686 1.4.15-10.el7_3.1 base memcached-devel.x86_64 1.4.15-10.el7_3.1 base opensips-memcached.x86_64 1.10.5-4.el7 epel php-Zendframework-Cache-Backend-Libmemcached.noarch php-pecl-memcached.x86_64 2.2.0-1.el7 epel python-memcached.noarch 1.48-4.el7 base uwsgi-router-memcached.x86_64 2.0.17.1-2.el7 epel [root@centos7 ~]#yum list "*memcached*" Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: Installed Packages memcached.x86_64 1.4.15-10.el7_3.1 @base Available Packages libmemcached.i686 1.0.16-5.el7 base libmemcached.x86_64 1.0.16-5.el7 base libmemcached-devel.i686 1.0.16-5.el7 base libmemcached-devel.x86_64 1.0.16-5.el7 base memcached-devel.i686 1.4.15-10.el7_3.1 base memcached-devel.x86_64 1.4.15-10.el7_3.1 base opensips-memcached.x86_64 1.10.5-4.el7 epel perl-Cache-Memcached.noarch 1.30-8.el7 epel php-Zendframework-Cache-Backend-Libmemcached.noarch 1.12.20-1.el7 epel php-Zendframework-Cache-Backend-Memcached.noarch 1.12.20-1.el7 epel php-pecl-memcached.x86_64 2.2.0-1.el7 epel python-memcached.noarch 1.48-4.el7 base uwsgi-router-memcached.x86_64 2.0.17.1-2.el7 epel [root@centos8 ~]#yum list "*memcached*" Last metadata expiration check: 0:09:46 ago on Thu 13 Feb 2020 07:14:15 PM CST. Installed Packages memcached.x86_64 1.5.9-2.el8 @AppStream Available Packages libmemcached.x86_64 1.0.18-15.el8 AppStream libmemcached-libs.i686 1.0.18-15.el8 AppStream libmemcached-libs.x86_64 1.0.18-15.el8 AppStream perl-Cache-Memcached.noarch 1.30-21.el8 epel python2-memcached.noarch 1.58-8.el8 epel python3-memcached.noarch 1.58-8.el8 epel
与memcached通信的不同语言的连接器。
libmemcached提供了C库和命令行工具。
范例：在CentOS 8 上安装memcached
[root@centos8 ~]#dnf install memcached -y
[root@centos8 ~]#rpm -ql memcached
/etc/sysconfig/memcached
/usr/bin/memcached
/usr/bin/memcached-tool
/usr/lib/.build-id
/usr/lib/.build-id/89
/usr/lib/.build-id/89/217dab806ba70f88fdfbd5a731d27b0382d51e
/usr/lib/systemd/system/memcached.service
/usr/share/doc/memcached
/usr/share/doc/memcached/AUTHORS
/usr/share/doc/memcached/ConTRIBUTORS
/usr/share/doc/memcached/COPYING
/usr/share/doc/memcached/ChangeLog
/usr/share/doc/memcached/NEWS
/usr/share/doc/memcached/README.md
/usr/share/doc/memcached/new_lru.txt
/usr/share/doc/memcached/protocol.txt
/usr/share/doc/memcached/readme.txt
/usr/share/doc/memcached/storage.txt
/usr/share/doc/memcached/threads.txt
/usr/share/man/man1/memcached-tool.1.gz
/usr/share/man/man1/memcached.1.gz
[root@centos8 ~]#grep -Ev "^#|^" /usr/lib/systemd/system/memcached.service
[Unit]
Description=memcached daemon
Before=httpd.service
After=network.target
[Service]
EnvironmentFile=/etc/sysconfig/memcached
ExecStart=/usr/bin/memcached -p{PORT} -u {USER} -m{CACHESIZE} -c {MAXCONN}OPTIONS
PrivateTmp=true
ProtectSystem=full
NonewPrivileges=true
PrivateDevices=true
CapabilityBoundingSet=CAP_SETGID CAP_SETUID CAP_SYS_RESOURCE
RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX
[Install]
WantedBy=multi-user.target
[root@centos8 ~]#cat /etc/sysconfig/memcached
PORT="11211"
USER="memcached"
MAXCONN="1024"
CACHESIZE="64"
OPTIONS="-l 127.0.0.1,::1"
[root@centos8 ~]#systemctl start memcached
[root@centos8 ~]#ss -ntul
Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port
udp UNCONN 0 0 127.0.0.1:323 0.0.0.0:*
udp UNCONN 0 0 [::1]:323 [::]:*
tcp LISTEN 0 128 0.0.0.0:22 0.0.0.0:*
tcp LISTEN 0 100 127.0.0.1:25 0.0.0.0:*
tcp LISTEN 0 128 127.0.0.1:11211 0.0.0.0:*
tcp LISTEN 0 128 [::]:22 [::]:*
tcp LISTEN 0 100 [::1]:25 [::]:*
tcp LISTEN 0 128 [::1]:11211 [::]:*
#修改端口绑定的IP为当前主机的所有IP
[root@centos8 ~]#vim /etc/sysconfig/memcached
[root@centos8 ~]#cat /etc/sysconfig/memcached
PORT="11211"
USER="memcached"
MAXCONN="1024"
CACHESIZE="64"
#OPTIONS="-l 127.0.0.1,::1"
OPTIONS=""
[root@centos8 ~]#
[root@centos8 ~]#systemctl restart memcached.service
[root@centos8 ~]#ss -ntul
Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port
udp UNCONN 0 0 127.0.0.1:323 0.0.0.0:*
udp UNCONN 0 0 [::1]:323 [::]:*
tcp LISTEN 0 128 0.0.0.0:22 0.0.0.0:*
tcp LISTEN 0 100 127.0.0.1:25 0.0.0.0:*
tcp LISTEN 0 128 0.0.0.0:11211 0.0.0.0:*
tcp LISTEN 0 128 [::]:22 [::]:*
tcp LISTEN 0 100 [::1]:25 [::]:*
tcp LISTEN 0 128 [::]:11211 [::]:*
协议
查看/usr/share/doc/memcached-1.4.15/protocol.txt
编译安装[root@centos7 ~]#yum –y install gcc libevent-devel
[root@centos7 ~]#wget http://memcached.org/files/memcached-1.5.22.tar.gz
[root@centos7 ~]#tar xvf memcached-1.5.22.tar.gz
[root@centos7 ~]#cd memcached-1.5.22/
[root@centos7 ~]#./configure --prefix=/apps/memcached
[root@centos7 ~]#make && make install
[root@centos7 ~]#tree /apps/memcached/
/apps/memcached/
├── bin
│?? └── memcached
├── include
│?? └── memcached
│?? └── protocol_binary.h
└── share
└── man
└── man1
└── memcached.1
6 directories, 3 files
[root@centos7 ~]#echo 'PATH=/apps/memcached/bin:$PATH' > /etc/profile.d/memcached.sh
[root@centos7 ~]#. /etc/profile.d/memcached.sh
[root@centos7 ~]#useradd -r -s /sbin/nologin memcached
[root@centos7 ~]#memcached -u memcached -m 2048 -c 65536 &
[root@centos7 ~]#ss -ntl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 *:11211 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 [::1]:25 [::]:*
LISTEN 0 128 [::]:11211 [::]:*
LISTEN 0 128 [::]:22 [::]:*
[root@centos7 ~]#
使用memcached
命令
五种基本 memcached 命令执行最简单的操作。这些命令和操作包括：
set
add
replace
get
delete
前三个命令是用于操作存储在 memcached 中的键值对的标准修改命令,都使用如下所示的语法： command参数说明如下： command set/add/replace key key 用于查找缓存值 flags 可以包括键值对的整型参数，客户机使用它存储关于键值对的额外信息 expiration time 在缓存中保存键值对的时间长度（以秒为单位，0 表示永远） bytes 在缓存中存储的字节点 value 存储的值（始终位于第二行）
范例：
# yum install telnet # telnet locahost 11211 stats add mykey 1 60 4 test STORED get mykey VALUE mykey 1 4 test END set mykey 1 60 5 test1 STORED get mykey VALUE mykey 1 5 test1 END delete mykey1 DELETED get mykey1 END flush_all OK get key3 END quit
add key flags exptime bytes ， 增加key，过期时间为秒，bytes为存储数据的字节数
