基於keepalived構建HA叢集
阿新 • • 發佈：2020-10-09
一、keepalived簡介
1.Keepalived的作用是檢測RealServer的健康狀態，如果有一臺RealServer伺服器宕機，Keepalived將檢測到，並將宕掉的RealServer伺服器從系統中剔除，當RealServer伺服器重新恢復正常工作後Keepalived自動將RealServer伺服器加入到伺服器群中。
2.keeepalived常見模型
<1>主從模型：（主節點修復後服務返回主節點）
定義一個VIP（定義在網絡卡別名之上）
在vrrp_instance做如下修改：
stateMASTER#從節點為BACKUP
priority101#指定優先順序，數字越大優先順序越高，主節點的優先順序高於從節點
<2>雙主模型：
建立兩個虛擬路由器，兩個節點互為主從
指定兩個vrrp_instance互為主從
virtual_router_id不相同
<3>LVS+keepalived
首先配置LVS
配置keepalived，新增虛擬服務，指定lvs模型及排程演算法
實戰篇
系統環境：centos6.4-i386
yum-yinstallkeepalived
keepalivedi686-1.2.7-3
二、主從模型HA叢集
修改主配置檔案：vim/etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
notify指令碼：
#!/bin/bash vip=172.16.15.114 #指定vip contact='[email protected]' notify() { mailsubject="`hostname` to be $1: $vip floating" mailbody="`date '+%F %H:%M:%S'`: vrrp transition, `hostname` changed to be $1" echo $mailbody | mail -s "$mailsubject" $contact } case "$1" in master) notify master /etc/rc.d/init.d/haproxy start exit 0 ;; backup) notify backup /etc/rc.d/init.d/haproxy stop exit 0 ;; fault) notify fault exit 0 ;; *) echo 'Usage: `basename $0` {master|backup|fault}' exit 1 ;; esac
以windows作為客戶端訪問172.16.15.114
關掉主服務：servicekeepalivedstop
三、雙主模型
原理：建立兩個虛擬路由器，兩個節點互為主從。
! Configuration File for keepalived
global_defs {
notification_email {
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_connect_timeout 3
smtp_server 127.0.0.1
router_id LVS_DEVEL
}
vrrp_script chk_haproxy {
script "killall -0 haproxy"
interval 1
weight 2
}
vrrp_script chk_mantaince_down {
script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
interval 1
weight 2
}
vrrp_instance VI_1 { #例項1
interface eth1
state MASTER # BACKUP for slave routers
priority 101 # 100 for BACKUP
virtual_router_id 51
garp_master_delay 1
authentication {
auth_type PASS
auth_pass password
}
track_interface {
eth1
}
virtual_ipaddress { #VIP1
172.16.15.115/16 dev eth1 label eth1:1
}
track_script {
chk_haproxy
chk_mantaince_down
}
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}
vrrp_instance VI_2 { #例項2
interface eth1
state BACKUP # BACKUP for slave routers
priority 100 # 100 for BACKUP
virtual_router_id 52
garp_master_delay 1
authentication {
auth_type PASS
auth_pass password
}
track_interface {
eth1
}
virtual_ipaddress { #VIP2
172.16.15.116/16 dev eth1 label eth1:2
}
track_script {
chk_haproxy
chk_mantaince_down
}
}在客戶端訪問172.16.15.115172.16.15.116
檢視IP
四、實現LVS+keepalived（LVS--DR）
1、首先配置LVS負載均衡叢集
注：LVS在會後續博文中做詳細介紹！！！
新增ipvsadm規則
#yum -y install ipvsadm #安裝ipvsadm #ipvsadm #檢視ipvsadm資訊及規則 #ipvsadm -A -t 172.16.15.117:80 -s rr #指定Director（排程器）
註釋：A(新增規則)
-t(指定協議為TCP)
172.16.15.117:80(指定VIP及埠)
-srr(指定排程演算法為rr)
#新增real_server
#ipvsadm -a -t 172.16.15.117:80 -r 172.16.15.5 -g #ipvsadm -a -t 172.16.15.117:80 -r 172.16.15.14 -g #ifconfig lo:0 $WEB_VIP netmask 255.255.255.255 broadcast $WEB_VIP #配置VIP，只允許本地迴環 # /sbin/route add -host $WEB_VIP dev lo:0 #新增本地路由 #echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore #echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce #echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore #echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
註釋：在此只新增兩個節點
-a：新增服務
-r172.16.15.5：指定服務IP
-g：指定lvs模型（預設DR）
2、配置基於keepalived（主從）高可用叢集
! Configuration File for keepalived
global_defs {
notification_email {
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_connect_timeout 3
smtp_server 127.0.0.1
router_id LVS_DEVEL
}
vrrp_script chk_schedown {
script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
interval 2
weight -2
}
vrrp_instance VI_1 {
interface eth1
state MASTER
priority 101
virtual_router_id 51
garp_master_delay 1
authentication {
auth_type PASS
auth_pass password
}
track_interface {
eth1
}
virtual_ipaddress {
172.16.15.117/16 #指定VIP,此處的VIP和lvs的VIP相同，因此不指定網絡卡
}
track_script {
chk_schedown
}
}
virtual_server 172.16.15.117 80 { #指定虛擬服務
delay_loop 6
lb_algo rr
lb_kind DR
persistence_timeout 50
protocol TCP
sorry_server 172.16.15.14 80 #錯誤頁面
real_server 172.16.15.5 80 { #指定rserver1
weight 1
HTTP_GET {
url {
path /
status_code 200 #狀態碼
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 172.16.15.14 80 { #指定rserver2
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3 #連線超時時間
nb_get_retry 3 #嘗試連線次數
delay_before_retry 3 #每次嘗試之前等待的時間
}
}
}在客戶端訪問172.16.15.117
轉載於:https://blog.51cto.com/dreamwolf/1301660