簡介：
Memcached主主複製是指在任意一臺Memcached服務器修改數據都會被同步到另外一臺，但是Memcached API客戶端是無法判斷連接到哪一臺Memcached服務器的，所以需要設置VIP地址，提供給Memcached API客戶端進行連接。可以使用keepalived產生的VIP地址連接主Memcached服務器，並且提供高可用架構。
Memcached架構圖：
案例環境：
三臺CentOs-7（主從服務器各一臺，客戶端一臺）
主服務器：192.168.120.128
從服務器：192.168.120.129
客戶端：192.168.120.133
具體實驗操作：
-------------------主服務器上配置memcached主緩存節點-----
[root@localhost ~]#systemctl stop firewalld.service
[root@localhost ~]#setenforce 0
[root@localhost ~]# mkdir /abc
[root@localhost ~]# mount.cifs //192.168.100.10/rhel7 /abc
Password for root@//192.168.100.10/rhel7:
[root@localhost ~]# cd /abc
[root@localhost abc]# ls
cobbler KVM memcached MongoDB mysql mysql.rar NEWYUM pv Y2C7
[root@localhost abc]# cd memcached/
[root@localhost memcached]# ls
LAMP-php5.6 libevent-2.1.8-stable.tar.gz magent-0.5.tar.gz memcache-2.2.7.tgz memcached-1.5.6.tar.gz
[root@localhost memcached]# tar zxvf libevent-2.1.8-stable.tar.gz -C /opt/
[root@localhost memcached]# tar zxvf memcached-1.5.6.tar.gz -C /opt/
[root@localhost memcached]# mkdir /opt/magent
[root@localhost memcached]# tar zxvf magent-0.5.tar.gz -C /opt/magent/
ketama.c
magent.c
ketama.h
Makefile
[root@localhost memcached]# yum install gcc gcc-c++ make -y
[root@localhost memcached]# cd /opt/libevent-2.1.8-stable/
[root@localhost libevent-2.1.8-stable]# ./configure --prefix=/usr/
[root@localhost libevent-2.1.8-stable]# make && make install
[root@localhost libevent-2.1.8-stable]# cd ../
[root@localhost opt]# cd memcached-1.5.6/
[root@localhost memcached-1.5.6]# ./configure --with-libevent=/usr/
[root@localhost memcached-1.5.6]# make && make install
[root@localhost memcached-1.5.6]# cd /opt/magent/
[root@localhost magent]# vim ketama.h
1 #ifndef SSIZE_MAX
2 #define SSIZE_MAX 32767
3 #endif
[root@localhost magent]# vim Makefile
1 LIBS = -levent -lm
[root@localhost magent]# make
gcc -Wall -O2 -g -c -o magent.o magent.c
gcc -Wall -O2 -g -c -o ketama.o ketama.c
gcc -Wall -O2 -g -o magent magent.o ketama.o -levent -lm
-------------------從服務器同主服務器一樣操作----------------
[root@localhost ~]#systemctl stop firewalld.service
[root@localhost ~]#setenforce 0
[root@localhost ~]# mkdir /abc
[root@localhost ~]# mount.cifs //192.168.100.10/rhel7 /abc
Password for root@//192.168.100.10/rhel7:
[root@localhost ~]# cd /abc
[root@localhost abc]# ls
cobbler KVM memcached MongoDB mysql mysql.rar NEWYUM pv Y2C7
[root@localhost abc]# cd memcached/
[root@localhost memcached]# ls
LAMP-php5.6 libevent-2.1.8-stable.tar.gz magent-0.5.tar.gz memcache-2.2.7.tgz memcached-1.5.6.tar.gz
[root@localhost memcached]# tar zxvf libevent-2.1.8-stable.tar.gz -C /opt/
[root@localhost memcached]# tar zxvf memcached-1.5.6.tar.gz -C /opt/
[root@localhost memcached]# yum install gcc gcc-c++ make -y
[root@localhost memcached]# cd /opt/libevent-2.1.8-stable/
[root@localhost libevent-2.1.8-stable]# ./configure --prefix=/usr/
root@localhost libevent-2.1.8-stable]# make && make install
[root@localhost memcached-1.5.6]# ./configure --prefix=/usr/local/memcached/ --with-libevent=/usr/
[root@localhost memcached-1.5.6]# make && make install
[root@localhost memcached-1.5.6]# ln -s /usr/local/memcached/bin/* /usr/local/bin/
-----------------------在主上操作----------------------------
[root@localhost magent]# yum install openssh-clients -y
[root@localhost magent]# cp magent /usr/bin/
[root@localhost magent]# scp magent [email protected]:/usr/bin/
[root@localhost magent]# yum install keepalived -y
-------------------在從上查看------------------------------
[root@localhost memcached-1.5.6]# cd /usr/bin/
[root@localhost bin]# yum install keepalived -y
----------------------編輯配置文件-----------------
[root@localhost magent]# vim /etc/keepalived/keepalived.conf
#刪除原有文件，編輯
1 ! Configuration File for keepalived
2
3 vrrp_script magent {
4 script "/opt/shell/magent.sh"
5 interval 2
6
7 }
8
9 global_defs {
10 notification_email {
11 [email protected]
12 [email protected]
13 [email protected]
14 }
15 notification_email_from [email protected]
16 smtp_server 192.168.200.1
17 smtp_connect_timeout 30
18 router_id MAGENT_HA
19 }
20
21 vrrp_instance VI_1 {
22 state MASTER
23 interface ens33
24 virtual_router_id 51
25 priority 100
26 advert_int 1
27 authentication {
28 auth_type PASS
29 auth_pass 1111
30 }
31 track_script {
32 magent
33 }
34 virtual_ipaddress {
35 192.168.120.188 #漂移地址
36
37 }
38 }
-----------------------在從服務器上--------------------------
[root@localhost ~]# cd /etc/keepalived/
[root@localhost keepalived]# ls
keepalived.conf
[root@localhost keepalived]# mv keepalived.conf keepalived.conf.bk
[root@localhost keepalived]# ls
keepalived.conf.bk
[root@localhost keepalived]# yum install openssh-clients -y
----------------------到主上將配置文件發送給從服務器-----------
[root@localhost magent]# cd /etc/keepalived/
[root@localhost keepalived]# ls
keepalived.conf
[root@localhost keepalived]# scp keepalived.conf [email protected]:/etc/keepalived/
[email protected]'s password:
keepalived.conf 100% 663 351.3KB/s 00:00
---------------------到從上更改配置文件----------------------------
[root@localhost keepalived]# vim keepalived.conf
18 router_id MAGENT_HB
22 state BACKUP
24 virtual_router_id 52
25 priority 90
---------------------回到主服務器上--------------------------------
[root@localhost keepalived]# mkdir /opt/shell
[root@localhost keepalived]# cd /opt/shell/
[root@localhost shell]# vim magent.sh
#!/bin/bash
K=ps -ef | grep keepalived | grep -v grep | wc -l
if [ $K -gt 0 ]; then
magent -u root -n 51200 -l 192.168.120.188 -p 12000 -s 192.168.120.128:11211 -b 192.168.120.129:11211
else
pkill -9 magent
fi
[root@localhost shell]# chmod +x magent.sh
[root@localhost shell]# systemctl start keepalived.service
#（等待幾分鐘，如果端口沒啓動，可能虛擬機有問題，可以更換虛擬機再試）#
[root@localhost shell]# netstat -ntap | grep 12000
tcp 0 0 192.168.120.188:12000 0.0.0.0: LISTEN 12088/magent
[root@localhost shell]# memcached -m 512k -u root -d -l 192.168.120.128 -p 11211
[root@localhost shell]# netstat -ntap | grep 11211
tcp 0 0 192.168.120.128:11211 0.0.0.0: LISTEN 15982/memcached
[root@localhost shell]# yum install telnet -y
[root@localhost shell]# telnet 192.168.175.128 11211
Trying 192.168.175.128...
Connected to 192.168.175.128.
Escape character is '^]'.
---------------------------在從上同樣操作------------------------------
[root@localhost keepalived]# mkdir /opt/shell
[root@localhost keepalived]# cd /opt/shell/
[root@localhost shell]# vim magent.sh
#!/bin/bash
K=ip addr | grep 192.168.120.188 | grep -v grep | wc -l
if [ $K -gt 0 ]; then
magent -u root -n 51200 -l 192.168.120.188 -p 12000 -s 192.168.120.128:11211 -b 192.168.120.129:11211
else
pkill -9 magent
fi
[root@localhost shell]# chmod +x magent.sh
[root@localhost shell]# systemctl start keepalived.service
[root@localhost shell]# netstat -ntap | grep 12000
tcp 0 0 192.168.120.188:12000 0.0.0.0: LISTEN 12088/magent
[root@localhost shell]# memcached -m 512k -u root -d -l 192.168.120.129 -p 11211
[root@localhost shell]# netstat -ntap | grep 11211
tcp 0 0 192.168.120.129:11211 0.0.0.0: LISTEN 51747/memcached
[root@localhost shell]# yum install telnet -y
[root@localhost shell]# telnet 192.168.120.129 11211
Trying 192.168.120.129...
Connected to 192.168.120.129.
Escape character is '^]'.
------------------------在客戶端上測試--------------------------
[root@localhost ~]# systemctl stop firewalld.service
[root@localhost ~]# setenforce 0
[root@localhost ~]# yum install telnet -y
[root@localhost ~]# telnet 192.168.120.188 12000
Trying 192.168.120.188...
Connected to 192.168.120.188.
Escape character is '^]'.
add username 0 0 7 #插入數據檢測
1234567
STORED
------------------打開兩臺從查看（主從同步）----------------------
[root@localhost memcached-1.5.6]# telnet 192.168.120.133 11211
Trying 192.168.120.133...
Connected to 192.168.120.133.
Escape character is '^]'.
get username 0 7 #查看數據
VALUE username 0 7
1234567 #同步過來了
END