LVS-DR負載均衡

server1:作為LinuxDirector

1.安裝ipvsadm（rh6.5需要配置yum源）

[[email protected] ~]# cat /etc/yum.repos.d/rhel-source.repo

[rhel-source]
name=Red Hat Enterprise Linux $releasever - $basearch - Source
baseurl=http://172.25.254.79/rhel6.5
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

[HighAvailability]
name
 
=HighAvailability
baseurl=http://172.25.254.79/rhel6.5/HighAvailability
enabled=1
gpgcheck=0

[LoadBalancer]
name=LoadBalancer
baseurl=http://172.25.254.79/rhel6.5/LoadBalancer
enabled=1
gpgcheck=0

[ResilientStorage]
name=ResilientStorage
baseurl=http://172.25.254.79/rhel6.5/ResilientStorage
enabled=1
gpgcheck=0

[ScalableFileSystem]
name
 
=ScalableFileSystem
baseurl=http://172.25.254.79/rhel6.5/ScalableFileSystem
enabled=1
gpgcheck=0

新增ipvsadm策略，將real-server與LinuxDIrector通過VIP繫結
[[email protected] ~]# ipvsadm -A -t 172.25.254.100:80 -s rr       ##新增VIP策略
[[email protected] ~]# ipvsadm -a -t 172.25.254.100:80 -r 172.25.254.241:80 -g  ##與172.25
 
.254.241繫結
[[email protected] ~]# ipvsadm -a -t 172.25.254.100:80 -r 172.25.254.1:80 -g

[[email protected] ~]# ipvsadm -l                                  ##list ipvsadm table
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.25.254.100:http rr
  -> server3:http                 Route   1      0          0         
  -> server2:http                 Route   1      0          0      

[root@server1 ~]# /etc/init.d/ipvsadm save                    #儲存策略

[root@server1 ~]# ip addr add 172.25.254.100/24 dev eth0      #給網絡卡新增real_server ip
[root@server1 ~]# ip addr | grep 100/24
    inet 172.25.254.100/24 scope global secondary eth0

server2:(real-server)

[root@server2 ~]# /etc/init.d/arptables_jf start       ##使客戶機不能直接通過100埠訪問
[root@server2 ~]# service httpd start
Redirecting to /bin/systemctl start  httpd.service
[root@server2 ~]# echo "server2" > /var/www/html/index.html
[root@server2 ~]# curl localhost
server2
[root@server2 ~]# ip addr add 172.25.254.100/24 dev eth0       ##通過VIP對Director識別

server3:(real-server)

[root@server3 ~]# /etc/init.d/arptables_jf start  
[root@server3 ~]# echo "server3" > /var/www/html/index.html
[root@server3 ~]# curl localhost
server3
[root@server3 ~]# ip addr add 172.25.254.100/24 dev eth0

foundation(客戶機):

lvs排程器將資料幀中的mac地址動態地更改server2或server3的mac地址，將修改後的資料幀傳送到區域網上，server2/3發現目標的VIP是我這個裝置上的，就根據路由表，直接相應客戶端。

##輪詢測試
[root@79 ~]# curl 172.25.254.100
server2
[root@79 ~]# curl 172.25.254.100
server3
[root@79 ~]# curl 172.25.254.100
server2
[root@79 ~]# curl 172.25.254.100
server3

[root@79 lvs]# arp -d 172.25.254.100   ##清理100的arp快取
[root@79 lvs]# arp -e 172.25.254.100   ##檢視ip源mac地址
Address                  HWtype  HWaddress           Flags Mask            Iface
172.25.254.100           ether   52:54:00:95:05:b1   C                     br0
[root@79 lvs]# ip addr              ##mac地址與server1相同
18: vnet2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br0 state UNKNOWN qlen 500
    link/ether fe:54:00:95:05:b1 brd ff:ff:ff:ff:ff:ff

二、Ldirectord 實現lvs健康檢查

ldirectord用來實現LVS負載均衡資源在主、備節點間的故障轉移。在首次啟動時，ldirectord可以自動建立IPVS表。此外，它還可以監控各RealServer的執行狀態，一旦發現某RealServer執行異常時，還可以將其從IPVS表中移除。

ldirectord 程序通過向RealServer的RIP傳送資源訪問請求並通過由RealServer返回的響應資訊來確定RealServer的執行狀態。在 Director上，每一個VIP需要一個單獨的ldirectord程序。如果RealServer不能正常響應Director上 ldirectord的請求，ldirectord程序將通過ipvsadm命令將此RealServer從IPVS表中移除。而一旦 RealServer再次上線，ldirectord會將其重新新增至IPVS表中

[root@server1 ~]# yum install -y ldirectord-3.9.5-3.1.x86_64.rpm 
[root@server1 ~]# cd /etc/ha.d/
[root@server1 ha.d]# ls
resource.d  shellfuncs
[root@server1 ha.d]# cp /usr/share/doc/ldirectord-3.9.5/ldirectord.cf  /etc/ha.d/

[root@server1 ha.d]# vim ldirectord.cf

virtual=172.25.27.100:80            # 此項用來定義LVS服務及其使用的VIP和PORT
        real=172.25.254.1:80 gate   # 定義RealServer，語法：real=RIP:port gate|masq|ipip [weight]
        real=172.25.254.241:80 gate
        fallback=127.0.0.1:80 gate  # 定義RealServer，語法：real=RIP:port gate|masq|ipip [weight]
       service=http                # 定義基於什麼服務來測試RealServer；
        scheduler=rr                # 排程演算法為rr
        #persistent=600             # 持久連線超時時間；
       #netmask=255.255.255.255
        protocol=tcp                # 定義此虛擬服務用到的協議；
        checktype=negotiate         # ldirectord程序用於監控RealServer的方法；{negotiate|connect|A number|off}
        checkport=80                # 指健康檢查使用的埠；
       request="index.html"        # 檢查RealServer用到的頁面
        receive="Test Page"         # 檢查RealServer用到的頁面內容
        virtualhost=www.x.y.z


[root@server1 ha.d]# /etc/init.d/ldirectord start
當把server2的apache關掉後
[root@server1 ~]# ipvsadm -L
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.25.254.100:http rr
  -> server3:http                 Route   1      0          0    

foundation:

[root@79 ~]# curl 172.25.254.100
server3
[root@79 ~]# curl 172.25.254.100
server3

提供當後端RS全部宕掉後，返回的fallback頁面，為本機httpd服務:

三、keepalived高可用

Keepalived是基於vrrp協議的一款高可用軟體。Keepalived有一臺主伺服器和多臺備份伺服器，在主伺服器和備份伺服器上面部署相同的服務配置，使用一個虛擬IP地址對外提供服務，當主伺服器出現故障時，虛擬IP地址會自動漂移到備份伺服器。

1.原始碼安裝Keepalived

[root@server1 ~]# /etc/init.d/ldirectord stop  #由於ldirectord 與Keepalived衝突，必須將ldirectord停掉
[root@server1 ~]# /etc/init.d/ldirectord stop
Stopping ldirectord... Success
##由於ldirectord 開機自啟，所以必須將其開機自啟關掉
[root@server1 ~]# chkconfig ldirectord off
[root@server1 ~]# tar zxf keepalived-1.3.6.tar.gz 
[root@server1 ~]# cd keepalived-1.3.6
[root@server1 ~]# ./configure --prefix=/usr/local/keepalived --with-init=SYSV
[root@server1 ~]# make
[root@server1 ~]# make install

2.Keepalived配置

root@server1 etc]# cd /usr/local/keepalived/etc/rc.d/init.d/
[root@server1 init.d]# ls
Keepalived
##由於keepalived所識別的環境與當前系統不符，所以需要製作軟連結
[root@server1 init.d]# ln -s /usr/local/keepalived/etc/keepalived/ /etc/             
[root@server1 init.d]# ln -s /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
[root@server1 init.d]# ln -s /usr/local/keepalived/sbin/keepalived /sbin/
[root@server1 init.d]# ln -s /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/

[root@server1 keepalived]# cd /usr/local/keepalived/etc/rc.d/init.d/
[root@server1 init.d]# chmod +x keepalived   #加可執行許可權
[root@server1 keepalived]# cd /etc/keepalived

[root@server1 keepalived]# vim /etc/keepalived/keepalived.conf

global_defs {

   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }

   notification_email_from Alexandre.Cassen@firewall.lo
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
   vrrp_skip_check_adv_addr
  #vrrp_strict     
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}
vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
              172.25.254.100  
}
}

virtual_server 172.25.27.100 80 {     ##虛擬主機

    delay_loop 6
    lb_algo rr
    lb_kind DR               ##是使用的DR模型
   # persistence_timeout 50  ##先將此註釋掉，可以更加直觀的感受到兩臺rs使用的DR進行的輪轉
    protocol TCP
    real_server 172.25.27.2 80 { 
                             ##real_server主機地址和埠兩臺rs均是使用的80埠
        weight 1             ##權重是可以自己進行修改的，在實際使用中，權重使用的不一樣是因為，權重較重一方的伺服器效能更加好
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
       }
    }
    real_server 172.25.254.141 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

foundation:

[root@79 ~]# curl 172.25.254.100
server2
[root@79 ~]# curl 172.25.254.100
server3
[root@79 ~]# curl 172.25.254.100
server2
[root@79 ~]# curl 172.25.254.100
server3

3.keepalived的bacup配置

開啟server4作為從伺服器，當主伺服器故障時，從伺服器會替代它的工作，並把故障的伺服器剔除。

將server4按照前面步驟佈置keeplived ，可直接將server1的keeplived 配置檔案複製過來，進行稍作修改

[root@server4 keepalived]# vim keepalived.conf   #修改state 和 priority

vrrp_instance VI_1 {
    state BACKUP  #將狀態由原來的master 改為備用
    interface eth0  
    virtual_router_id 51
    priority 50    #更改優先順序
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
[root@server4 keepalived]# /etc/init.d/keepalived start  
[root@server4 ~]# ip addr add 172.25.254.100/24 dev eth0      #新增real_server ip

server1:

[root@server1～]#echo c > /proc/sysrq-trigger  #故意讓系統崩潰，實現宕機的目的

foundation:

檢測仍能正常工作

[root@79 ~]# curl 172.25.254.100
server2
[root@79 ~]# curl 172.25.254.100
server3
[root@79 ~]# curl 172.25.254.100
server2
[root@79 ~]# curl 172.25.254.100
server3
測試並檢視IP 和mac 地址，發現此時服務已經完全有server4接管，從而實現了lvs叢集高可用