負載均衡實現

利用紅帽自帶的lvs套件，完成負載均衡，模式DR，調度算法最小連接優先

虛擬訪問IP地址爲192.168.1.201

lvs1:192.168.1.111 172.16.1.111

lvs2:192.168.1.112 172.16.1.112

webserver1:192.168.1.41 權值爲1

webserver2:192.168.1.42 權值爲1

1.對yum源添加，/etc/yum.repo.d/iso.repo配置如下，然後安裝Piranha

[rhel-iso]
name=Red Hat Enterprise 
baseurl=file:///iso
enabled=1
gpgcheck=0
[rhel-server]
name=Red Hat Enterprise 
baseurl=file:///iso/Server
enabled=1
gpgcheck=0
[rhel-ScalableFileSystem]
name=Red Hat Enterprise 
baseurl=file:///iso/ScalableFileSystem
enabled=1
gpgcheck=0
[rhel-ResilientStorage]
name=Red Hat Enterprise 
baseurl=file:///iso/ResilientStorage
enabled=1
gpgcheck=0
[rhel-HighAvailability]
name=Red Hat Enterprise 
baseurl=file:///iso/HighAvailability
enabled=1
gpgcheck=0
[rhel-LoadBalancer]
name=Red Hat Enterprise 
baseurl=file:///iso/LoadBalancer
enabled=1
gpgcheck=0

2.用圖形化界面配置lvs負載均衡，或者直接修改/etc/sysconfig/ha/lvs.conf效果相同

3.配置成功後，圖形界面監控結果：

lvs查看IP分流情況

[root@lvs1 ~]# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.1.201:webcache wlc
  -> 192.168.1.41:webcache        Route   1      0          0         
  -> 192.168.1.42:webcache        Route   1      0          0 

lvs成功配置後的日誌
[root@lvs1 ~]# tail -f /var/log/messages
Apr 23 15:25:51 lvs1 pulse[1421]: STARTING PULSE AS MASTER
Apr 23 15:26:09 lvs1 pulse[1421]: partner dead: activating lvs
Apr 23 15:26:09 lvs1 lvsd[1423]: starting virtual service jsprun1 active: 8080
Apr 23 15:26:09 lvs1 lvsd[1423]: create_monitor for jsprun1/Webserver1 running as pid 1433
Apr 23 15:26:09 lvs1 lvsd[1423]: create_monitor for jsprun1/Webserver2 running as pid 1434
Apr 23 15:26:09 lvs1 nanny[1434]: starting LVS client monitor for 192.168.1.201:8080 -> 192.168.1.42:8080
Apr 23 15:26:09 lvs1 nanny[1433]: starting LVS client monitor for 192.168.1.201:8080 -> 192.168.1.41:8080
Apr 23 15:26:09 lvs1 nanny[1434]: [ active ] making 192.168.1.42:8080 available
Apr 23 15:26:09 lvs1 nanny[1433]: [ active ] making 192.168.1.41:8080 available
Apr 23 15:26:14 lvs1 pulse[1425]: gratuitous lvs arps finished

利用虛擬IP訪問，我的數據庫集羣5臺，lvs4臺，所以數據庫就不開了，但是可以看到tomcat在正常工作：

當webserver1出現故障，虛擬IP訪問正常其實這時由正常的服務器分擔1的工作，webserver1修復後，lvs經過最小連接計算，將訪問分發給服務器1，直到兩臺負載達到均衡。