在CentOS7上部署Memcached主主複製+Keepalived高可用架構

時間 2020-01-02

標籤 centos7 centos 部署 memcached 複製 keepalived 可用架構欄目 Tomcat 简体版

原文原文鏈接

原理：

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一臺，可是Memcached API客戶端是沒法判斷鏈接到哪一臺Memcached服務器的，因此須要設置VIP地址，提供給Memcached API客戶端進行鏈接。能夠使用Keepalived產生的VIP地址鏈接主Memcached服務器，而且提供高可用架構。c++

使用兩臺Memcached服務器，一臺客戶機來完成，實驗環境表以下：
shell

1.配置memcached主緩存節點和從緩存節點-----兩臺配置相同vim

[root@localhost ~]# tar zxvf libevent-2.1.8-stable.tar.gz -C /opt/   //解包//
 [root@localhost ~]# tar zxvf memcached-1.5.6.tar.gz -C /opt/
 [root@localhost ~]# mkdir /opt/magent
 [root@localhost ~]# tar zxvf magent-0.5.tar.gz -C /opt/magent/ 
 [root@localhost opt]#cd libevent-2.1.8-stable/
 [root@localhost libevent-2.1.8-stable]# yum install gcc gcc-c++ make -y
 [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 ../memcached-1.5.6/
 [root@localhost memcached-1.5.6]# ./configure --with-libevent=/usr

 [root@localhost memcached-1.5.6]# ln -s /usr/lib/libevent-2.1.so.6 /usr/lib64/libevent-2.1.so.6    //軟連接//

2.關閉防火牆並開啓memcached服務緩存

[root@localhost memcached-1.5.6]# systemctl stop firewalld.service 
[root@localhost memcached-1.5.6]# setenforce 0
[root@localhost memcached-1.5.6]# memcached -d -m 32m -p 11211 -u root
[root@localhost memcached-1.5.6]# netstat -ntap | grep 11211
tcp        0      0 0.0.0.0:11211           0.0.0.0:*               LISTEN      11224/memcached     
tcp6       0      0 :::11211                :::*                    LISTEN      11224/memcached

3.在主服務器上安裝magentbash

[root@localhost memcached-1.5.6]# cd /opt/magent/
[root@localhost magent]# ls
ketama.c  ketama.h  magent.c  Makefile
[root@localhost magent]# vim ketama.h

#ifndef SSIZE_MAX
#define SSIZE_MAX 32767
#endif
[root@localhost magent]# vim Makefile 
LIBS = -levent -lm //第一行末尾加-lm （不是數字1
LIBS = -levent -lm
CFLAGS = -Wall -O2 -g

[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

4.把生成的mgent程序讓系統識別服務器

ls一下可看到magent可執行程序
[root@localhost magent]# ls
ketama.c  ketama.h  ketama.o  magent  magent.c  magent.o  Makefile
[root@localhost magent]# cp magent /usr/bin/

5.把產生的magent文件直接複製到從服務器。架構

[root@localhost bin]# yum install openssh-clients -y
[root@localhost bin]# scp magent root@192.168.126.166:/usr/bin/

6.安裝keepalived，修改默認配置文件。ssh

[root@localhost bin]# yum install keepalived -y
[root@localhost bin]# vim /etc/keepalived/keepalived.conf 
! Configuration File for keepalived
vrrp_script magent {
        script "/opt/shell/magent.sh"
        interval 2
}

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id MAGENT_HA    //主服務器名稱//
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33     //網卡名稱//
    virtual_router_id 51
    priority 100    //優先級//
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111   
    }
    virtual_ipaddress {
        192.168.126.188     //虛擬IP//
    }
track_script {
        magent     //函數//
}
}

7.從服務器上安裝keepalived，配置文件進行修改。tcp

[root@localhost bin]# vim /etc/keepalived/keepalived.conf 
! Configuration File for keepalived
vi keepalived.conf
vrrp_script magent {
        script "/opt/shell/magent.sh"
        interval 2
}

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id MAGENT_HB      //從服務器的名稱//
}

vrrp_instance VI_1 {
    state BACKUP            //從服務器的熱備狀態要修改爲BACKUP//
    interface ens33  //網卡名稱//
    virtual_router_id 52    //不能與主服務器相同//
    priority 90       //從調度器的優先級要小於主的//
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.126.188     //虛擬IP//
    }
track_script {        //函數//
        magent  
}
}

8.在主服務器上設置magent管理腳本ide

[root@localhost bin]# mkdir /opt/shell
[root@localhost bin]# vim /opt/shell/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 192.168.126.188 -p 12000 -s 192.168.126.138:11211 -b 192.168.126.166:11211
else
pkill -9 magent
fi

參數註解：
-n 51200 //定義用戶最大鏈接數
-l 192.168.126.188 //指定虛擬IP
-p 12000  //指定端口號
-s //指定主緩存服務器
-b //指定從緩存服務器

[root@localhost shell]# chmod +x magent.sh   // 增長執行權限//

9.在從服務器上操做

[root@localhost bin]# mkdir /opt/shell
[root@localhost bin]# cd /opt/shell/
[root@localhost shell]# vim magent.sh
[root@localhost shell]# vim magent.sh
腳本內容以下，與主服務器腳本有區別！
#!/bin/bash
K=`ip addr | grep 192.168.126.188 | grep -v grep | wc -l`
if [ $K -gt 0 ]; then
        magent -u root -n 51200 -l 192.168.126.188 -p 12000 -s 192.168.126.138:11211 -b 192.168.126.166:11211
else
pkill -9 magent
fi  
[root@localhost shell]# chmod +x magent.sh

10.開始驗證

1）啓動主服務器

[root@localhost shell]# systemctl start keepalived.service 
[root@localhost shell]# netstat -ntap | grep 12000  //確認magent運行//
tcp        0      0 192.168.126.188:12000   0.0.0.0:*               LISTEN      12422/magent

2）啓動從服務器

[root@localhost shell]# systemctl start keepalived.service 
[root@localhost shell]# netstat -ntap | grep 12000
tcp        0      0 192.168.126.188:12000   0.0.0.0:*               LISTEN      11716/magent

3）在主服務器上使用telnet進行簡單驗證複製功能

[root@localhost shell]# telnet 192.168.126.188 12000  //用漂移地址登錄服務//
Trying 192.168.126.188...
Connected to 192.168.126.188.
Escape character is '^]'.
add username 0 0 7      //添加一條鍵值數據//
1234567
STORED

在從服務器上查看
[root@localhost shell]# telnet 192.168.126.188 12000 
Trying 192.168.126.188...
Connected to 192.168.126.188.
Escape character is '^]'.
get username    //查看鍵值數據
VALUE username 0 7
1234567         //內容存在，寫入成功//
END

11.在客戶端用漂移地址登錄服務

[root@localhost ~]# yum install telnet -y
[root@localhost ~]# telnet 192.168.126.188 12000 
Trying 192.168.126.188...
Connected to 192.168.126.188.
Escape character is '^]'.
add username 0 0 8    //添加一條鍵值數據//
12345678
STORED

1）在主服務器和從服務器上查看是否寫入成功。

主服務器
get username
VALUE username 0 8
12345678
END

從服務器
get username
VALUE username 0 8
12345678
END

2）把主服務器停了業務不影響

[root@localhost shell]# systemctl stop keepalived.service
[root@localhost shell]# ip addr
inet 192.168.126.138/24 brd 192.168.126.255 scope global dynamic ens33

3）在從服務器上查看

[root@localhost shell]# ip addr
inet 192.168.126.166/24 brd 192.168.126.255 scope global dynamic ens33
       valid_lft 1146sec preferred_lft 1146sec
    inet 192.168.126.188/32 scope global ens33
能夠看到漂移地址已經轉移到從服務器上了，說明從已接受工做。

3）再把主服務器開啓

[root@localhost shell]# systemctl start keepalived.service 
[root@localhost shell]# ip addr
inet 192.168.126.138/24 brd 192.168.126.255 scope global dynamic ens33
       valid_lft 1145sec preferred_lft 1145sec
    inet 192.168.126.188/32 scope global ens33
       valid_lft forever preferred_lft forever
漂移地址再次轉移到主服務器上，接手地址，服務依然不受影響。

實驗成功