一、简介
keepalived 简介:是服务器高可用的一个重要软件,它的核心组件有vrrp ,stack, checker ,ipvs, warpper, watch dog
它是vrrp协议的实现,原生设计目的为高可用ipvs服务;keepalived能够通过配置文件中定义生成ipvs规则
并能够对RS的健康状态进行检测;vrrp_script,vrrp_track;
双主模型的实现
简介:双方模型(主/备,备/主)的这里的意思是,一个keepalived配置中,一个虚拟IP地址为主,另一个为备。而在另一个
keepalived的配置中,与其它主机则恰恰相反,一个虚拟IP地址为备,另一个为主
以下为此次双主模型实现的拓扑
二、HA Cluster配置的前提;
(1)要点:各节点之间的时间秘需要同步:
# ntpdate 172.16.0.1 (注此:处可自己在网上找个时间同步服务器)
(2)确保iptables及selinux不会阻碍:
# iptables -F && setenforce 0
(3)各节点之间可通过主机名互相通信(对keepalived并非必须):
# vim /etc/hosts
172.16.250.140 kpl1
172.16.250.158 kpl2 两台keepalived主机都要修改
(4)各节点之间root用户可以基于密钥认证的ssh通信
# ssh-copy-id -i 172.16.250.140
# ssh-copy-id -i 172.16.250.158
三、dr集群配置
此处使用dr集群类型
首先将dr模型配置好
编辑setkp.sh
#!/bin/bash
vip=172.16.26.126
vip2=172.16.26.127
mask=255.255.255.255
interface=’lo:0′
interface2=’lo:1′
eth=’eno16777736:0′
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 $interface $vip netmask $mask broadcast $vip up
ifconfig $interface2 $vip2 netmask $mask broadcast $vip2 up
route add -host $vip dev $interface
route add -host $vip2 dev $interface2
;;
dstart)
ifconfig $eth $vip/32 netmask $mask broadcast $vip up
;;
dstop)
ifconfig $eth down
;;
stop)
ifconfig $interface down
ifconfig $interface2 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
;;
status)
ifconfig
cat /proc/sys/net/ipv4/conf/all/arp_ignore
cat /proc/sys/net/ipv4/conf/lo/arp_ignore
cat /proc/sys/net/ipv4/conf/all/arp_announce
cat /proc/sys/net/ipv4/conf/lo/arp_announce
;;
*)
echo “Usage: $(basename $0) {dstart|dstop|start|stop}”
exit 1
esac
RS1、RS2主机中都执行执行此脚本
# sh setkp.sh start
# sh setkp.sh status 可用来查看当前网络的配置状态
RS1、RS2主机中安装httpd并启动
# yum -y install httpd && systemctl start httpd
RS1 # echo “<h1>RS1</h1>” > /usr/share/nginx/html/index.html
RS2 # echo “<h1>RS2</h1>” > /usr/share/nginx/html/index.html
四、keepalived配置
keepalived,keepalived2 中安装nginx(httpd和nginx都可以,此处用来做为keepalived的本身的提供sorry server)
当dr集群的两台节点都停止时,会由keepalived本身来提供一个页面
# yum -y install nginx keepalived ipvsadm && systemctl start nginx
# echo “<h1>sorry server keepalived 1 </h1>” > /usr/share/nginx/html/index.html
# echo “<h1>sorry server keepalived 2 </h2>” > /usr/share/nginx/html/index.html
在一台keepalived主机上进行测试
# curl 172.16.251.232
<h1>RS1</h2>
# curl 172.16.250.159
<h1>RS2</h1>
keepalived,keepalived2 中在 /etc/keepalived/目录下编辑一个脚本来用来在主备变化,或服务down掉时发邮件给系统用户
# vim kmail.sh
#!/bin/bash
contact=’root@localhost’
notify(){
mailsubject=”$(hostname) to be $1:vip floating”
mailbody=”$(date +’%F %T’):vrrp transition, $(hostname) change to be $1″
echo $mailbody | mail -s “$mailsubject” $contact
}
case $1 in
master )
notify master
;;
backup )
notify backup
;;
fault )
notify fault
;;
*)
echo “Usage:$(basename $0) {master |backup|fault}”
;;
esac
#chmod +x kmail.sh
注:keepalived的两台主机的配置基本相同,当配置模型为主/备模型的时候,主备之间需要修改三个指令
分别为 router_id kpl1 在keepalived2上时需要修改为 router_id kpl2
state MASTER 在keepalived2上时需要修改为 state BACKUP
priority 100 在keepalived2上时需要修改为 priority 90 (此处的值比主服务器的小便可以)
以下主/备的配置示例
先把备的服务器启动
# tcpdump -i eno33554984 -nn host 224.0.61.61
可使用tcpdump 抓取组播地址 来查看其通过组播方式传递的心跳信息
以下的配置文件便是keepavlied双主模型的实现
对防火墙打标记
keepalived 1
# iptables -t mangle -A PREROUTING -d 172.16.26.126 -p tcp –dport 80 -j MARK –set-mark 3
# iptables -t mangle -A PREROUTING -d 172.16.26.127 -p tcp –dport 80 -j MARK –set-mark 3
# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
root@localhost
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id kpl1
vrrp_mcast_group4 224.0.61.61
}
vrrp_instance VI_1 {
state MASTER
interface eno33554984
virtual_router_id 55
priority 100
advert_int 1
notify_master “/etc/keepalived/kmail.sh master”
notify_backup “/etc/keepalived/kmail.sh backup”
notify_fault “/etc/keepalived/kmail.sh fault”
authentication {
auth_type PASS
auth_pass zE2kNsRQ
}
virtual_ipaddress {
172.16.26.126 dev eno33554984 label eno33554984:0
}
}
vrrp_instance VI_2 {
state BACKUP
interface eno33554984
virtual_router_id 66
priority 90
advert_int 1
notify_master “/etc/keepalived/kmail.sh master”
notify_backup “/etc/keepalived/kmail.sh backup”
notify_fault “/etc/keepalived/kmail.sh fault”
authentication {
auth_type PASS
auth_pass zE2kfsRQ
}
virtual_ipaddress {
172.16.26.127 dev eno33554984 label eno33554984:1
}
}
virtual_server fwmark 3 {
delay_loop 2
lb_algo wrr
lb_kind DR
nat_mask 255.255.0.0
protocol TCP
sorry_server 127.0.0.1 80
real_server 172.16.251.232 80 {
weight 3
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 2
nb_get_retry 3
delay_before_retry 3
}
}
real_server 172.16.250.159 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 2
nb_get_retry 3
delay_before_retry 3
}
}
keepalived 2
# iptables -t mangle -A PREROUTING -d 172.16.26.126 -p tcp –dport 80 -j MARK –set-mark 3
# iptables -t mangle -A PREROUTING -d 172.16.26.127 -p tcp –dport 80 -j MARK –set-mark 3
# vim /etc/keepavlied/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
root@localhost
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id kpl2
vrrp_mcast_group4 224.0.61.61
}
vrrp_instance VI_1 {
state BACKUP
interface eno33554984
virtual_router_id 55
priority 90
advert_int 1
notify_master “/etc/keepalived/kmail.sh master”
notify_backup “/etc/keepalived/kmail.sh backup”
notify_fault “/etc/keepalived/kmail.sh fault”
authentication {
auth_type PASS
auth_pass zE2kNsRQ
}
virtual_ipaddress {
172.16.26.126 dev eno33554984 label eno33554984:0
}
}
vrrp_instance VI_2 {
state MASTER
interface eno33554984
virtual_router_id 66
priority 100
advert_int 1
notify_master “/etc/keepalived/kmail.sh master”
notify_backup “/etc/keepalived/kmail.sh backup”
notify_fault “/etc/keepalived/kmail.sh fault”
authentication {
auth_type PASS
auth_pass zE2kfsRQ
}
virtual_ipaddress {
172.16.26.127 dev eno33554984 label eno33554984:1
}
}
virtual_server fwmark 3 {
delay_loop 2
lb_algo wrr
lb_kind DR
nat_mask 255.255.0.0
protocol TCP
sorry_server 127.0.0.1 80
real_server 172.16.251.232 80 {
weight 3
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 2
nb_get_retry 3
delay_before_retry 3
}
}
real_server 172.16.250.159 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 2
nb_get_retry 3
delay_before_retry 3
}
}
五、测试
此时可以测试其访问
当一个keepavlied停止时
当RS2停止时
当RS1,RS2都停止时
六、keepavlied配置指令说明
虚拟路由器段
state MASTER:当前节点在虚拟路由器中的初始状态;
interface ETHERCARD: vrrp实际工作的网卡接口
virtual_route_id 51 :虚拟路由器ID,范围0-255;
priority 100 :当前物理节点在此虚拟路由器中的优先级;
advert_int 1:每隔多久发送心跳(通行的时间间隔)
auth_type PASS :选择认证机制
auth_pass 1111 :密码 八位有效
virtual_ipaddress :定义虚拟IP
track_interface : 定义要监控的接口
notify_master <STRING> | <QUOTED-STRING> :当前节点变为主节点时用STRING脚本通告
notfy_backup<STRING> | <QUOTED-STRING> : 当前节点变为主节时用 STRING脚本通告
notify_fault<STRING> | <QUOTED-STRING> : 当前节点上不了线时用STRING脚本通告
notify<STRING> | <QUOTED-STRING> : 如果三种状态用一个脚本来实现用STRING脚本通告
虚拟服务段
lb_algo rr | wrr|lc|lblc|sh|dh :定义负载均衡调度算法
delay_loop<INT>::定义服务轮询时间间隔
bl_kind NAT |DR |TUN :集群的类型
persistence_time_out<INT> :持久连接时长
protocol TCP : 服务协议
sorry_server<IPADDR><PORT>:所有RS均故障时,提供sorry server的服务器;
real_server<IPADDR><PORT>:
weight<INT>:权重
notify_up<STRING>|<QUOTED-STRING> : 节点上线通知脚本
notify_down <STRING>|<QUOTED-STRNG>:节点离线通知脚本;
#HTTP_GET|SSL_GET|TCP_CHECK|SMTP_CHECK|MISC_CHECK :支持的所以健康状态的检测方式
url:健康状态检测时请求的资源的URL
delay_before_retry<INT> :两次尝试之间的时间间隔
connect_timeoute<STRING>:连接的超时时长
connect_ip<IP ADDRESS>:向此处指定的地址发测试请求
connect_port<PORT>:向此处指定的PORT发测试请求
bindto<IP ADDRESS>:指定测试请求报文的源IP
bind_port<PORT>: 指定测试请求报文的源PORT
原创文章,作者:kang,如若转载,请注明出处:http://www.178linux.com/79190