1.keepalived介紹
keepalived最初是專為lvs負載平衡軟體設計的,用來管理和監控lvs叢集系統中各個服務節點的狀態,後來又加入了實現高可用的vrrp功能。 keepalived除了能夠管理lvs軟體外,還能支援其他服務的高可用解決方案。
keepalived透過vrrp協定實現高可用功能的。 vrrp(virtual router redundancy protocol)虛擬路由冗餘協定。 vrrp出現的目的就是為了解決靜態路由單點故障問題,它能保證當個別節點宕機時,整個網路可以不間斷地運作。
2.keepalived高可用故障轉移原理
keepalived高可用服務之間的故障轉移,是透過vrrp來實現的。在keepalived服務工作時,主master節點會不斷地向備節點發送(多播的方式)心跳訊息,用來告訴備backup節點自己還活著。
當主節點發生故障時,無法給備節點發送心跳訊息,如果備節點無法繼續偵測到來自主節點的心跳。就會呼叫自身的接管程序,接管主節點的ip資源和服務。當主節點恢復時,備節點又會釋放主節點故障時自身接管的ip資源和服務,恢復到原來的備用角色
##3.安裝nginx
3.1.主節點(192.168.80.22)
3.1.1.安裝編譯工具與函式庫檔案yum -y install make zlib zlib-devel gcc-c++ libtool openssl openssl-devel
#进入目录 cd /usr/local/develop/anginx #上传安装文件并解压 tar -zxvf pcre-8.38.tar.gz #进入安装目录 cd pcre-8.38 #检查配置 ./configure #编译、安装 make && make install #查看pcre版本 pcre-config --version
#进入目录 cd /usr/local/develop/anginx #上传安装文件,并解压 tar -zxvf nginx-1.8.1.tar.gz #进入安装目录 cd nginx-1.8.1 #检查配置 ./configure --prefix=/usr/local/develop/anginx/webserver/nginx --with-http_stub_status_module --with-http_ssl_module --with-pcre=/usr/local/develop/anginx/pcre-8.38 #编译安装 make && make install #查看nginx版本 /usr/local/develop/anginx/webserver/nginx/sbin/nginx -v -------------------------------------------------------- [root@hadoop02 webserver]# /usr/local/develop/anginx/webserver/nginx/sbin/nginx -v nginx version: nginx/1.8.1 #配置nginx(检查) /usr/local/develop/anginx/webserver/nginx/sbin/nginx -t #nginx管理命令 /usr/local/develop/anginx/webserver/nginx/sbin/nginx # 启动 nginx /usr/local/develop/anginx/webserver/nginx/sbin/nginx -s stop # 停止 nginx /usr/local/develop/anginx/webserver/nginx/sbin/nginx -s reload # 重新载入配置文件 /usr/local/develop/anginx/webserver/nginx/sbin/nginx -s reopen # 重启 nginx
vi nginx.conf #user nobody; worker_processes 1; #error_log logs/error.log; #error_log logs/error.log notice; #error_log logs/error.log info; pid logs/nginx.pid; events { worker_connections 1024; } http { include mime.types; default_type application/octet-stream; log_format main '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"'; access_log logs/access.log main; sendfile on; #tcp_nopush on; #keepalive_timeout 0; keepalive_timeout 65; #gzip on; #添加tomcat列表,真实应用服务器都放在这 upstream tomcat_pool{ #server tomcat地址:端口号 weight表示权值,权值越大,被分配的几率越大; server 192.168.80.22:8080 weight=4 max_fails=2 fail_timeout=30s; server 192.168.80.22:8081 weight=4 max_fails=2 fail_timeout=30s; } server { listen 80; server_name tomcat_pool; #charset koi8-r; #access_log logs/host.access.log main; location / { #root html; #index index.html index.htm; proxy_pass http://tomcat_pool; #转向tomcat处理 proxy_set_header host $host; proxy_set_header x-real-ip $remote_addr; proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for; } #error_page 404 /404.html; # redirect server error pages to the static page /50x.html # error_page 500 502 503 504 /50x.html; location = /50x.html { root html; } }
3.2.備節點(192.168.80.21)
說明:安裝方式同nginx主節點。4.安裝keepalived
4.1.主節點(192.168.80.22)
#安装keepalived yum install keepalived -y #启动keepalived服务 /etc/init.d/keepalived start ------------------------------------------- [root@hadoop02 anginx]# /etc/init.d/keepalived start 正在启动 keepalived: [确定] [root@hadoop02 anginx]# ps -ef |grep keepalived root 15723 1 0 00:59 ? 00:00:00 /usr/sbin/keepalived -d root 15724 15723 0 00:59 ? 00:00:00 /usr/sbin/keepalived -d root 15725 15723 0 00:59 ? 00:00:00 /usr/sbin/keepalived -d root 15731 15622 0 00:59 pts/1 00:00:00 grep keepalived [root@hadoop02 anginx]# #设置开机自启动 echo "/etc/init.d/keepalived start" >>/etc/rc.local #关闭keepalived服务 /etc/init.d/keepalived stop #编辑keepalived配置文件 vi /etc/keepalived/keepalived.conf ----------------------------------------------------------- ! configuration file for keepalived global_defs { notification_email { acassen@firewall.loc failover@firewall.loc sysadmin@firewall.loc } notification_email_from alexandre.cassen@firewall.loc smtp_server 192.168.200.1 smtp_connect_timeout 30 router_id lb01 } vrrp_instance vi_1 { state master interface eth1 virtual_router_id 55 priority 150 advert_int 1 authentication { auth_type pass auth_pass server123 } virtual_ipaddress { 192.168.80.100 dev eth1 label eth1:1 } } ...........................................................
#安装keepalived
yum install keepalived -y
#启动keepalived服务
/etc/init.d/keepalived start
-------------------------------------------
[root@hadoop02 anginx]# /etc/init.d/keepalived start
正在启动 keepalived: [确定]
[root@hadoop02 anginx]# ps -ef |grep keepalived
root 15723 1 0 00:59 ? 00:00:00 /usr/sbin/keepalived -d
root 15724 15723 0 00:59 ? 00:00:00 /usr/sbin/keepalived -d
root 15725 15723 0 00:59 ? 00:00:00 /usr/sbin/keepalived -d
root 15731 15622 0 00:59 pts/1 00:00:00 grep keepalived
[root@hadoop02 anginx]#
#设置开机自启动
echo "/etc/init.d/keepalived start" >>/etc/rc.local
#关闭keepalived服务
/etc/init.d/keepalived stop
#编辑keepalived配置文件
vi /etc/keepalived/keepalived.conf
-----------------------------------------------------------------
! configuration file for keepalived
global_defs {
notification_email {
acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
notification_email_from alexandre.cassen@firewall.loc
smtp_server 192.168.200.1
smtp_connect_timeout 30
router_id lb02
}
vrrp_instance vi_1 {
state backup
interface eth1
virtual_router_id 55
priority 100
advert_int 1
authentication {
auth_type pass
auth_pass server123
}
virtual_ipaddress {
192.168.80.100 dev eth1 label eth1:1
}
}
.............................................................
#5.1.啟動主備節點的keepalived服務
#在节点一执行(192.168.80.22)
/etc/init.d/keepalived start
-------------------------------------
[root@hadoop02 anginx]# ps -ef |grep keepalived
root 15788 1 0 01:09 ? 00:00:00 /usr/sbin/keepalived -d
root 15790 15788 0 01:09 ? 00:00:00 /usr/sbin/keepalived -d
root 15791 15788 0 01:09 ? 00:00:00 /usr/sbin/keepalived -d
root 15807 15622 0 01:33 pts/1 00:00:00 grep keepalived
[root@hadoop02 anginx]#
#在节点二执行(192.168.80.21)
/etc/init.d/keepalived start
---------------------------------------
[root@hadoop01 ~]# ps -ef |grep keepalived
root 11542 1 0 01:30 ? 00:00:00 /usr/sbin/keepalived -d
root 11544 11542 0 01:30 ? 00:00:00 /usr/sbin/keepalived -d
root 11545 11542 0 01:30 ? 00:00:00 /usr/sbin/keepalived -d
root 11550 11512 0 01:33 pts/1 00:00:00 grep keepalived
[root@hadoop01 ~]#
http://192.168.80.100/session-redis-demo/
5.3.停止主節點keepalived服務
#在节点一执行(192.168.80.22) /etc/init.d/keepalived stop #观察备节点变化 ip addr ------------------------------------------- [root@hadoop01 ~]# ip addr 1: lo: <loopback,up,lower_up> mtu 65536 qdisc noqueue state unknown link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth1: <broadcast,multicast,up,lower_up> mtu 1500 qdisc pfifo_fast state up qlen 1000 link/ether 00:50:56:38:e5:46 brd ff:ff:ff:ff:ff:ff inet 192.168.80.21/24 brd 192.168.80.255 scope global eth1 inet 192.168.80.100/32 scope global eth1:1 inet6 fe80::250:56ff:fe38:e546/64 scope link valid_lft forever preferred_lft forever [root@hadoop01 ~]#
http://192.168.80.100/session-redis-demo/
6.keepalived nginx整合
#說明:編寫nginx守護腳本,如果nginx服務出現故障,則停止目前節點的keepalived服務。自動切換到備用節點。
6.1.寫nginx守護腳本vi nginx_check.sh
--------------------------------------
#!/bin/bash
while true
do
if [ $(netstat -tlnp|grep nginx|wc -l) -ne 1 ]
then
/etc/init.d/keepalived stop
fi
sleep 2
done
#给脚本授权
chmod u+x nginx_check.sh
#执行脚本
nohup /usr/local/develop/anginx/shell/nginx_check.sh &
#停止主节点nginx服务
/usr/local/develop/anginx/webserver/nginx/sbin/nginx -s stop
#查找进程
[root@hadoop02 ~]# ps -ef |grep nginx
root 15915 1 0 01:51 ? 00:00:00 /bin/bash /usr/local/develop/anginx/shell/nginx_check.sh
root 16516 15753 0 01:54 pts/5 00:00:00 grep nginx
[root@hadoop02 ~]#
#观察备用节点变化【服务正常】
ip addr
--------------------------------------
[root@hadoop01 shell]# ip addr
1: lo: <loopback,up,lower_up> mtu 65536 qdisc noqueue state unknown
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth1: <broadcast,multicast,up,lower_up> mtu 1500 qdisc pfifo_fast state up qlen 1000
link/ether 00:50:56:38:e5:46 brd ff:ff:ff:ff:ff:ff
inet 192.168.80.21/24 brd 192.168.80.255 scope global eth1
inet 192.168.80.100/32 scope global eth1:1
inet6 fe80::250:56ff:fe38:e546/64 scope link
valid_lft forever preferred_lft forever
[root@hadoop01 shell]#
#再次重新启动主节点nginx和keepalived服务
/usr/local/develop/anginx/webserver/nginx/sbin/nginx
/etc/init.d/keepalived start
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