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 restrict 172.18.17.0 mask 255.255.0.0 nomodify notrap server 127.127.1.0 fudge 127.1.1.0 stratum 8 [root@shiyan7 ~ ]# ntpdate 172.18.17.31
关闭Selinux
[root@shiyan7 ~ ]# vim /etc/selinux/config SELINUX=disabled
关闭防火墙
[root@shiyan7 ~ ]# systemctl stop firewalld [root@shiyan7 ~ ]# systemctl disable firewalld [root@shiyan7 ~ ]# iptables -F
主机名解析配置
[root@shiyan7 ~ ]# cat /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 172.18.17.34 shiyan.fore 172.18.17.31 shiyan.one 172.18.17.32 shiyan7.two 172.18.17.33 shiyan7.thy
Master/Backup初始化配置
安装KeepAlived、Nginx软件
[root@shiyan7 ~ ]# yum install keepalived Nginx ipvsadm
Nginx1/2初始化配置
安装Nginx软件
[root@shiyan7 ~ ]# yum install Nginx #这里配置一个配置VIP及更改内核参数的脚本。 [root@shiyan7 ~ ]# touch roush.sh [root@shiyan7 ~ ]# chmod +x roush.sh [root@shiyan7 ~ ]# vim roush.sh #!/bin/bash # vip="172.18.17.30" netmask="255.255.255.255" iface="lo:0" case $1 in start) echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce ifconfig $iface $vip netmask $netmask broadcast $vip up route add -host $vip dev $iface ;; stop) ifconfig $iface down echo 0 > /proc/sys/net/ipv4/conf/all/arp_ignore echo 0 > /proc/sys/net/ipv4/conf/lo/arp_ignore echo 0 > /proc/sys/net/ipv4/conf/all/arp_announce echo 0 > /proc/sys/net/ipv4/conf/lo/arp_announce ;; esac
Ngxin1配置
[root@shiyan7 ~ ]# ./roush.sh start [root@shiyan7 ~ ]# mkdir /app/Nginx/html [root@shiyan7 ~ ]# echo "<h2>RS1:172.18.17.32</h2>" > /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 { listen 80 default_server; listen [::]:80 default_server; server_name _; root /app/Nginx/html;#修改root这里的路径，其他不需要 # Load configuration files for the default server block. include /etc/Nginx/default.d/*.conf; location / { } error_page 404 /404.html; location = /40x.html { } error_page 500 502 503 504 /50x.html; } [root@shiyan7 ~ ]# systemctl start Nginx #测试Nginx服务 [root@yum ~ ]# curl http://172.18.17.33 <h2>RS1:172.18.17.33</h2>
Ngxin2配置
[root@shiyan7 ~ ]# ./roush.sh start [root@shiyan7 ~ ]# mkdir /app/Nginx/html [root@shiyan7 ~ ]# echo "<h2>RS1:172.18.17.33</h2>" > /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 { listen 80 default_server; listen [::]:80 default_server; server_name _; root /app/Nginx/html;#修改root这里的路径，其他不需要 # Load configuration files for the default server block. include /etc/Nginx/default.d/*.conf; location / { } error_page 404 /404.html; location = /40x.html { } error_page 500 502 503 504 /50x.html; } [root@shiyan7 ~ ]# systemctl start Nginx #测试Nginx服务 [root@yum ~ ]# curl http://172.18.17.34 <h2>RS1:172.18.17.34</h2>
Master上的配置
#配置Nginx1-Sorry Server [root@shiyan7 ~ ]# mkdir /app/Nginx/html [root@shiyan7 ~ ]# echo "Sorry server-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 { listen 80 default_server; listen [::]:80 default_server; server_name _; root /app/Nginx/html;#修改root这里的路径，其他不需要 # Load configuration files for the default server block. include /etc/Nginx/default.d/*.conf; location / { } error_page 404 /404.html; location = /40x.html { } error_page 500 502 503 504 /50x.html; } [root@shiyan7 ~ ]# systemctl start Nginx #测试Nginx1-Sorry Server [root@yum ~ ]# curl http://172.18.17.31 Sorry server-1 #配置Keepalived服务 [root@shiyan7 ~ ]# cp /etc/keepalived/keepalived.conf{,.bak} [root@shiyan7 ~ ]# vim /etc/keepalived/keepalived.conf vrrp_instance Ha_1 { state MASTER interface ens33 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 172.18.17.30/16 dev ens33 } } virtual_server 172.18.17.30 80 { delay_loop 6 lb_algo lc lb_kind DR persistence_timeout 50 protocol TCP sorry_server 172.18.17.31 80 real_server 172.18.17.32 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 172.18.17.33 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } } [root@shiyan7 ~ ]#systemctl start keepalived #查看配置是否成功 [root@shiyan7 ~ ]# ip a l 2: ens33: <broADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:1b:f5:ae brd ff:ff:ff:ff:ff:ff inet 172.18.17.31/16 brd 172.18.255.255 scope global ens33 valid_lft forever preferred_lft forever inet 172.18.17.30/16 scope global secondary ens33 valid_lft forever preferred_lft forever [root@shiyan7 ~ ]# ipvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 172.18.17.30:80 lc persistent 50 -> 172.18.17.32:80 Route 1 0 0 -> 172.18.17.33:80 Route 1 0 0
Backup上的配置
#配置Nginx1-Sorry Server [root@shiyan7 ~ ]# mkdir /app/Nginx/html [root@shiyan7 ~ ]# echo "Sorry server-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 { listen 80 default_server; listen [::]:80 default_server; server_name _; root /app/Nginx/html;#修改root这里的路径，其他不需要 # Load configuration files for the default server block. include /etc/Nginx/default.d/*.conf; location / { } error_page 404 /404.html; location = /40x.html { } error_page 500 502 503 504 /50x.html; } [root@shiyan7 ~ ]# systemctl start Nginx #测试Nginx1-Sorry Server [root@yum ~ ]# curl http://172.18.17.34 Sorry server-2 #配置Keepalived服务 [root@shiyan7 ~ ]# cp /etc/keepalived/keepalived.conf{,.bak} [root@shiyan7 ~ ]# vim /etc/keepalived/keepalived.conf vrrp_instance Ha_1 { state MASTER interface ens33 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 172.18.17.30/16 dev ens33 } } virtual_server 172.18.17.30 80 { delay_loop 6 lb_algo lc lb_kind DR persistence_timeout 50 protocol TCP sorry_server 172.18.17.32 80 real_server 172.18.17.32 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 172.18.17.33 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } } [root@shiyan7 ~ ]#systemctl start keepalived [root@shiyan7 ~ ]# ip a l 2: ens33: <broADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:1b:f5:ae brd ff:ff:ff:ff:ff:ff inet 172.18.17.34/16 brd 172.18.255.255 scope global ens33 valid_lft forever preferred_lft forever #这里是Baskup服务所以不会有VIP地址 [root@shiyan7 ~ ]# ipvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 172.18.17.30:80 lc persistent 50 -> 172.18.17.32:80 Route 1 0 0 -> 172.18.17.33:80 Route 1 0 0
测试服务
#正常测试 [root@yum ~ ]# curl http://172.18.17.30 <h2>RS1:172.18.17.32</h2> [root@yum ~ ]# curl http://172.18.17.30 <h2>RS1:172.18.17.34</h2> #关闭Nginx1测试 [root@yum ~ ]# curl http://172.18.17.30 <h2>RS1:172.18.17.33</h2> #关闭所有Nginx服务测试 [root@yum ~ ]# curl http://172.18.17.30 Sorry server-1 #关闭Master测试 [root@yum ~ ]# curl http://172.18.17.30 Sorry server-2
