背景介绍
我们都知道一台服务器能提供的资源是有限的，如果想打破这个限制，只有两个办法，一个是购买硬件，提升服务器性能，但是性价比过高，而第二种方法这则是，使用集群软件让两台服务器处理一个服务的不同请求，分带单台服务器的负载，从而提升性能，实现这一的软件开源著名的有Nginx或者Lvs，这里我们使用的是LVS，但是lvs需要一个调度服务器，这样调度服务器就是一个集训的单点故障，一旦调度服务器出现故障，整个集群便崩溃，所以我们需要两台调度节点，一旦一个调度节点损坏，那么另一台调度节点开始工作，这里我们使用Keepalived开源软件实现调度器的高可用。
逻辑图介绍
1.用户在访问Nginx的时候，先通过VIP访问Master1，由Master指定那个real-server提供服务
2.在Master通过lvs-Dr指定的算法选定由Nginx1来提供服务，那么数据在通过VIP发送到Nginx1上
3.Nginx处理完请求后，在通过自身的VIP将处理后的请求直接发送给User
注明：
如果Master出现故障，那么Baskup将替代Master工作
如果Nginx1出现故障，那么Nginx2将提点Nginx1工作
如果Nginx1没有出现故障，那么LVS服务使用算法会将请求平均到Nginx1和Nginx2上
如果两台Nginx同时出现故障，那么Master会提供Sorry Server服务
物理拓扑图及环境介绍
服务器：使用虚拟机虚拟4套服务器
操作系统：CentOS7.3
HA软件/LVs软件：keepalived
Web软件：Nginx
IP及主机名配置
VIP：172.18.17.30
Master：
主机名：shiyan7.one
IP地址：172.18.17.31
Backup
主机名：shiyan7.fore
IP地址：172.18.17.34
主机名：shiyan7.two
IP地址：172.18.17.34
主机名：shiyan7.thy
IP地址：172.18.17.34
4台服务器初始化配置
同步时间服务
#Master配置NTP服务器 [root@shiyan7~]#vim/etc/ntp.conf restrict172.18.17.0mask255.255.0.0nomodifynotrap server127.127.1.0 fudge127.1.1.0stratum8 [root@shiyan7~]#ntpdate172.18.17.31
关闭Selinux
[root@shiyan7~]#vim/etc/selinux/config SELINUX=disabled
关闭防火墙
[root@shiyan7~]#systemctlstopfirewalld [root@shiyan7~]#systemctldisablefirewalld [root@shiyan7~]#iptables-F
主机名解析配置
[root@shiyan7~]#cat/etc/hosts 127.0.0.1localhostlocalhost.localdomainlocalhost4localhost4.localdomain4 ::1localhostlocalhost.localdomainlocalhost6localhost6.localdomain6 172.18.17.34shiyan.fore 172.18.17.31shiyan.one 172.18.17.32shiyan7.two 172.18.17.33shiyan7.thy
Master/Backup初始化配置
安装KeepAlived、Nginx软件
[root@shiyan7~]#yuminstallkeepalivedNginxipvsadm
Nginx1/2初始化配置
安装Nginx软件
[root@shiyan7~]#yuminstallNginx #这里配置一个配置VIP及更改内核参数的脚本。 [root@shiyan7~]#touchroush.sh [root@shiyan7~]#chmod+xroush.sh [root@shiyan7~]#vimroush.sh #!/bin/bash # vip="172.18.17.30" netmask="255.255.255.255" iface="lo:0" case$1in start) echo1>/proc/sys/net/ipv4/conf/all/arp_ignore echo1>/proc/sys/net/ipv4/conf/lo/arp_ignore echo2>/proc/sys/net/ipv4/conf/all/arp_announce echo2>/proc/sys/net/ipv4/conf/lo/arp_announce ifconfig$iface$vipnetmask$netmaskbroadcast$vipup routeadd-host$vipdev$iface ;; stop) ifconfig$ifacedown echo0>/proc/sys/net/ipv4/conf/all/arp_ignore echo0>/proc/sys/net/ipv4/conf/lo/arp_ignore echo0>/proc/sys/net/ipv4/conf/all/arp_announce echo0>/proc/sys/net/ipv4/conf/lo/arp_announce ;; esac
Ngxin1配置
[root@shiyan7~]#./roush.shstart [root@shiyan7~]#mkdir/app/Nginx/html [root@shiyan7~]#echo"<h1>RS1:172.18.17.32</h1>">/app/Nginx/html/index.html [root@shiyan7~]#cp/etc/Nginx/Nginx/conf{,.bak}#备份原文件 [root@shiyan7~]#vim/etc/Nginx/Nginx/conf server{ listen80default_server; listen[::]:80default_server; server_name_; root/app/Nginx/html;#修改root这里的路径，其他不需要 #Loadconfigurationfilesforthedefaultserverblock. include/etc/Nginx/default.d/*.conf; location/{ } error_page404/404.html; location=/40x.html{ } error_page500502503504/50x.html; } [root@shiyan7~]#systemctlstartNginx #测试Nginx服务 [root@yum~]#curlhttp://172.18.17.33 <h1>RS1:172.18.17.33</h1>
Ngxin2配置
[root@shiyan7~]#./roush.shstart [root@shiyan7~]#mkdir/app/Nginx/html [root@shiyan7~]#echo"<h1>RS1:172.18.17.33</h1>">/app/Nginx/html/index.html [root@shiyan7~]#cp/etc/Nginx/Nginx/conf{,.bak}#备份原文件 [root@shiyan7~]#vim/etc/Nginx/Nginx/conf server{ listen80default_server; listen[::]:80default_server; server_name_; root/app/Nginx/html;#修改root这里的路径，其他不需要 #Loadconfigurationfilesforthedefaultserverblock. include/etc/Nginx/default.d/*.conf; location/{ } error_page404/404.html; location=/40x.html{ } error_page500502503504/50x.html; } [root@shiyan7~]#systemctlstartNginx #测试Nginx服务 [root@yum~]#curlhttp://172.18.17.34 <h1>RS1:172.18.17.34</h1>
Master上的配置
#配置Nginx1-SorryServer [root@shiyan7~]#mkdir/app/Nginx/html [root@shiyan7~]#echo"Sorryserver-1">/app/Nginx/html/index.html [root@shiyan7~]#cp/etc/Nginx/Nginx/conf{,.bak}#备份原文件 [root@shiyan7~]#vim/etc/Nginx/Nginx/conf server{ listen80default_server; listen[::]:80default_server; server_name_; root/app/Nginx/html;#修改root这里的路径，其他不需要 #Loadconfigurationfilesforthedefaultserverblock. include/etc/Nginx/default.d/*.conf; location/{ } error_page404/404.html; location=/40x.html{ } error_page500502503504/50x.html; } [root@shiyan7~]#systemctlstartNginx #测试Nginx1-SorryServer [root@yum~]#curlhttp://172.18.17.31 Sorryserver-1 #配置Keepalived服务 [root@shiyan7~]#cp/etc/keepalived/keepalived.conf{,.bak} [root@shiyan7~]#vim/etc/keepalived/keepalived.conf vrrp_instanceHa_1{ stateMASTER interfaceens33 virtual_router_id51 priority100 advert_int1 authentication{ auth_typePASS auth_pass1111 } virtual_ipaddress{ 172.18.17.30/16devens33 } } virtual_server172.18.17.3080{ delay_loop6 lb_algolc lb_kindDR persistence_timeout50 protocolTCP sorry_server172.18.17.3180 real_server172.18.17.3280{ weight1 HTTP_GET{ url{ path/ status_code200 } connect_timeout3 nb_get_retry3 delay_before_retry3 } } real_server172.18.17.3380{ weight1 HTTP_GET{ url{ path/ status_code200 } connect_timeout3 nb_get_retry3 delay_before_retry3 } } } [root@shiyan7~]#systemctlstartkeepalived #查看配置是否成功 [root@shiyan7~]#ipal 2:ens33:<broADCAST,MULTICAST,UP,LOWER_UP>mtu1500qdiscpfifo_faststateUPqlen1000 link/ether00:0c:29:1b:f5:aebrdff:ff:ff:ff:ff:ff inet172.18.17.31/16brd172.18.255.255scopeglobalens33 valid_lftforeverpreferred_lftforever inet172.18.17.30/16scopeglobalsecondaryens33 valid_lftforeverpreferred_lftforever [root@shiyan7~]#ipvsadm-ln IPVirtualServerversion1.2.1(size=4096) ProtLocalAddress:PortSchedulerFlags ->RemoteAddress:PortForwardWeightActiveConnInActConn TCP172.18.17.30:80lcpersistent50 ->172.18.17.32:80Route100 ->172.18.17.33:80Route100
Backup上的配置
#配置Nginx1-SorryServer [root@shiyan7~]#mkdir/app/Nginx/html [root@shiyan7~]#echo"Sorryserver-2">/app/Nginx/html/index.html [root@shiyan7~]#cp/etc/Nginx/Nginx/conf{,.bak}#备份原文件 [root@shiyan7~]#vim/etc/Nginx/Nginx/conf server{ listen80default_server; listen[::]:80default_server; server_name_; root/app/Nginx/html;#修改root这里的路径，其他不需要 #Loadconfigurationfilesforthedefaultserverblock. include/etc/Nginx/default.d/*.conf; location/{ } error_page404/404.html; location=/40x.html{ } error_page500502503504/50x.html; } [root@shiyan7~]#systemctlstartNginx #测试Nginx1-SorryServer [root@yum~]#curlhttp://172.18.17.34 Sorryserver-2 #配置Keepalived服务 [root@shiyan7~]#cp/etc/keepalived/keepalived.conf{,.bak} [root@shiyan7~]#vim/etc/keepalived/keepalived.conf vrrp_instanceHa_1{ stateMASTER interfaceens33 virtual_router_id51 priority100 advert_int1 authentication{ auth_typePASS auth_pass1111 } virtual_ipaddress{ 172.18.17.30/16devens33 } } virtual_server172.18.17.3080{ delay_loop6 lb_algolc lb_kindDR persistence_timeout50 protocolTCP sorry_server172.18.17.3280 real_server172.18.17.3280{ weight1 HTTP_GET{ url{ path/ status_code200 } connect_timeout3 nb_get_retry3 delay_before_retry3 } } real_server172.18.17.3380{ weight1 HTTP_GET{ url{ path/ status_code200 } connect_timeout3 nb_get_retry3 delay_before_retry3 } } } [root@shiyan7~]#systemctlstartkeepalived [root@shiyan7~]#ipal 2:ens33:<broADCAST,LOWER_UP>mtu1500qdiscpfifo_faststateUPqlen1000 link/ether00:0c:29:1b:f5:aebrdff:ff:ff:ff:ff:ff inet172.18.17.34/16brd172.18.255.255scopeglobalens33 valid_lftforeverpreferred_lftforever #这里是Baskup服务所以不会有VIP地址 [root@shiyan7~]#ipvsadm-ln IPVirtualServerversion1.2.1(size=4096) ProtLocalAddress:PortSchedulerFlags ->RemoteAddress:PortForwardWeightActiveConnInActConn TCP172.18.17.30:80lcpersistent50 ->172.18.17.32:80Route100 ->172.18.17.33:80Route100
测试服务
#正常测试 [root@yum~]#curlhttp://172.18.17.30 <h1>RS1:172.18.17.32</h1> [root@yum~]#curlhttp://172.18.17.30 <h1>RS1:172.18.17.34</h1> #关闭Nginx1测试 [root@yum~]#curlhttp://172.18.17.30 <h1>RS1:172.18.17.33</h1> #关闭所有Nginx服务测试 [root@yum~]#curlhttp://172.18.17.30 Sorryserver-1 #关闭Master测试 [root@yum~]#curlhttp://172.18.17.30 Sorryserver-2
