目录大数据全系列 教程
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A A
White Night
规划：node1和node5作为负载均衡服务器，node2上的tomcat1和tomcat2还是RS服务器。
修改node2的tomcat1和tomcat2上的index.jps,去掉样式和图片，去掉动静分离的干扰。
tomcat1的index.jsp
xxxxxxxxxxfrom 192.168.20.102:8080 tomcat1tomcat2上的index.jsp
xxxxxxxxxxfrom 192.168.20.102:9090 tomcat2
xxxxxxxxxxupstream rss { server 192.168.20.102:8080; server 192.168.20.102:9090;}server { # check_nginx.sh脚本执行时使用 listen 80; server_name localhost; location / { root html; }}server { listen 80; server_name 192.168.20.200; location / { proxy_pass http://rss/; }}xxxxxxxxxx[root@node1 ~]# cd /usr/local/nginx/conf/[root@node1 conf]# scp nginx.conf 192.168.20.105:`pwd`xxxxxxxxxx#通过访问check.html页面来检查nginx是否宕机url="http://127.0.0.1/check.html"code=`curl -s -o /dev/null -w %{http_code} $url`#通过判断相应编码是否是200来确定nginx宕机if [ $code -ne 200 ];then sleep 1 code=`curl -s -o /dev/null -w %{http_code} $url` if [ $code -ne 200 ];then #确定nginx是宕机，关闭本机的keepalived systemctl stop keepalived fifixxxxxxxxxxscp /home/check_nginx.sh node5:/home
xxxxxxxxxx[root@node1 home]# cd /usr/local/nginx/html[root@node1 html]# vim check.htmlcheck nginxxxxxxxxxxx[root@node1 html]# scp check_nginx.sh 192.168.20.105:/home/分别在node1和node5上的/usr/local/nginx/html目录下创建一个check.html
xxxxxxxxxx[root@node1 home]# cd /usr/local/nginx/html/[root@node1 html]# pwd/usr/local/nginx/html[root@node1 html]# vim check.htmlcheck nginx分别在node1上和node5上测试check_nginx.sh是否可以正确的检查出nginx是否宕机：
xxxxxxxxxx[root@node1 ~]# sh -x /home/check_nginx.sh + url=http://127.0.0.1/check.html++ curl -s -o /dev/null -w '%{http_code}' http://127.0.0.1/check.html+ code=200+ '[' 200 -ne 200 ']'以上提示表示nginx正常提供服务。
xxxxxxxxxx[root@nginx1 ~]# sh -x /home/check_nginx.sh+ url=http://127.0.0.1/check.html++ curl -s -o /dev/null -w '%{http_code}' http://127.0.0.1/check.html+ code=404 或 502 或 ... 非200的值+ '[' 502 -ne 200 ']'以上提示表示nginx已经宕机了。
xxxxxxxxxx[root@node1 ~]# yum install keepalived -y[root@node5 ~]# yum install keepalived -y如果某项不记得如何配置，可以新开一个终端，通过man keepalived.conf命令进行查看配置说明
xxxxxxxxxxglobal_defs { #配置接收邮件的邮箱地址，指定keepalived在发生切换时需要发送email到的邮箱地址，一行一个 notification_email { .com } notification_email_from keepmanager.com #指定发件人 smtp_server 192.168.20.1 #指定邮件smtp服务器的地址 smtp_connect_timeout 30 #指定smtp连接的超时时间 router_id node1 #运行keepalived机器的一个标识}#手动定义一个检查机制vrrp_script chk_nginx { script "/home/check_nginx.sh" interval 2#每隔2秒检查一次 weight -20}vrrp_instance VI_1 { #指定实例的初始化状态，两台路由器都启动后，马上会发生竞选。priority优先级高的被选为Master #这里的MASTER并不能代表当前实例一直未MASTER state MASTER interface ens33 #实例绑定的网卡设备 virtual_router_id 101#VRID的标记(0-255) priority 100#优先级 该值高的实例优先竞选为MASTER，低的为BACKUP advert_int 1 #检查间隔，默认为1s #认证的设置 authentication { auth_type PASS#认证的方式 PASS 或AH auth_pass 1111 # 认证的密码 } #指定虚拟ip地址，也是VIP virtual_ipaddress { 192.168.20.200/24 dev ens33 label ens33:3 } track_script { chk_nginx #调用上面定义好检测 }}3.将配置文件远程拷贝到node5上一份
xxxxxxxxxx [root@node1 ~]# scp /etc/keepalived/keepalived.conf root@192.168.20.105:/etc/keepalived/root@192.168.20.105's password: keepalived.conf 100% 1434 926.0KB/s 00:00 4.去node5上修改keepalived.conf文件
xxxxxxxxxxrouter_id node5....vrrp_instance VI_1 { state BACKUP interface ens33 virtual_router_id 105 priority 90 ……}5.node1上启动keepalived
xxxxxxxxxx[root@node1 keepalived]# systemctl start keepalived[root@node1 keepalived]# systemctl status keepalived● keepalived.service - LVS and VRRP High Availability Monitor Loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled) Active: active (running) since Wed 2021-09-01 18:10:50 CST; 26s ago Process: 14753 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS) Main PID: 14754 (keepalived) Tasks: 2 (limit: 4911) Memory: 5.4M CGroup: /system.slice/keepalived.service ├─14754 /usr/sbin/keepalived -D └─14755 /usr/sbin/keepalived -D
8月 04 18:10:54 node0 Keepalived_vrrp[14755]: Sending gratuitous ARP on ens33 for 192.168.20.200
6.node1上检查
xxxxxxxxxx[root@node1 keepalived]# ifconfigens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 ......ens33:3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.20.200 netmask 255.255.255.0 broadcast 0.0.0.0 ether 00:0c:29:01:4c:80 txqueuelen 1000 (Ethernet)浏览器访问测试：http://192.168.20.200,并不断刷新，网页显示结果在8080和9090之间切换。
7.node5上启动keepalived
xxxxxxxxxx[root@node5 keepalived]# systemctl start keepalived[root@node5 keepalived]# systemctl status keepalived● keepalived.service - LVS and VRRP High Availability Monitor Loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled) Active: active (running) since 三 2021-09-01 12:19:18 CST; 6s ago Process: 9666 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS) Main PID: 9667 (keepalived) CGroup: /system.slice/keepalived.service ├─9667 /usr/sbin/keepalived -D ├─9668 /usr/sbin/keepalived -D └─9669 /usr/sbin/keepalived -D
9月 01 12:19:18 node5 Keepalived_vrrp[9669]: VRRP_Script(chk_nginx) succeeded9月 01 12:19:21 node5 Keepalived_vrrp[9669]: VRRP_Instance(VI_1) Transition to MASTER STATE9月 01 12:19:22 node5 Keepalived_vrrp[9669]: VRRP_Instance(VI_1) Entering MASTER STATE9月 01 12:19:22 node5 Keepalived_vrrp[9669]: VRRP_Instance(VI_1) setting protocol VIPs.9月 01 12:19:22 node5 Keepalived_vrrp[9669]: Sending gratuitous ARP on ens33 for 192.168.20.2009月 01 12:19:22 node5 Keepalived_vrrp[9669]: VRRP_Instance(VI_1) Sending/queueing gratuitous ARPs on ens33 for 192.168.20.2009月 01 12:19:22 node5 Keepalived_vrrp[9669]: Sending gratuitous ARP on ens33 for 192.168.20.2009月 01 12:19:22 node5 Keepalived_vrrp[9669]: Sending gratuitous ARP on ens33 for 192.168.20.2009月 01 12:19:22 node5 Keepalived_vrrp[9669]: Sending gratuitous ARP on ens33 for 192.168.20.2009月 01 12:19:22 node5 Keepalived_vrrp[9669]: Sending gratuitous ARP on ens33 for 192.168.20.2008.node5上检查,没有启动ens:3的网卡 ??? 为何也有？
xxxxxxxxxx[root@node5 keepalived]# ifconfig……9.将node1上的nginx down掉并测试
xxxxxxxxxx[root@node1 keepalived]# systemctl stop nginx [root@node1 keepalived]# ifconfig
node5上查看，
xxxxxxxxxx[root@node5 keepalived]# ifconfig10.将node1上的nginx和keepalived起来并测试
xxxxxxxxxx[root@node1 keepalived]# systemctl start nginx[root@node1 keepalived]# systemctl start keepalived node1上查看，
xxxxxxxxxx[root@node1 keepalived]# ifconfig[root@node1 ~]# ps aux |grep keepalived
关闭Nginx的时候，keepalived不能被关闭，出现如下错误提示（/var/log/messages）：
xxxxxxxxxxAug 9 12:46:02 node3 setroubleshoot[34963]: failed to retrieve rpm info for /home/check_nginx.shAug 9 12:46:02 node3 setroubleshoot[34963]: SELinux is preventing keepalived from getattr access on the file /home/check_nginx.sh. For complete SELinux messages run: sealert -l e024cc7f-9ba2-41fd-acb1-6c0e12ed25f9
检查SELinux子系统是否启动：
xxxxxxxxxx[root@node5 ~]# getenforce Enforcing #表示正在启用[root@node5 ~]# sestatusSELinux status: enabledSELinuxfs mount: /sys/fs/selinuxSELinux root directory: /etc/selinuxLoaded policy name: targetedCurrent mode: enforcing #在启用Mode from config file: enforcingPolicy MLS status: enabledPolicy deny_unknown status: allowedMemory protection checking: actual (secure)Max kernel policy version: 31
临时关闭SELinux:
xxxxxxxxxx[root@node5 ~]# setenforce 0[root@node5 ~]# getenforce Permissive #说明临时关闭成功重启系统后，临时关闭将失效。所以需要再次进行永久关闭：
xxxxxxxxxx[root@node5 ~]# vim /etc/selinux/configSELINUX=disabled #默认值是enforcing重启keepalived，再次查看/var/log/messages,不再出现之前bug。