yum安裝
yum -y install keepalived
配置文件：
/etc/keepalived/ keepalived.conf
日志文件：
/var/log/messages
注意：在啟動(dòng)之前，一定要配置下keepalived.conf文件
源碼編譯安裝
安裝依賴(lài)：
yum install curl gcc autoconf automake openssl-devel libnl3-devel \
iptables-devel ipset-devel net-snmp-devel libnfnetlink-devel file-devel
yum install glib2-devel
yum install json-c-devel
下載源碼：
wget -c https://keepalived.org/software/keepalived-2.2.8.tar.gz
curl --progress https://keepalived.org/software/keepalived-2.2.8.tar.gz
解壓源碼：
tar -xvf keepalived-2.2.8.tar.gz
編譯安裝：
cd keepalived-2.2.8
./build_setup
./configure --prefix=/usr/local/keepalived-2.2.8
make && make install
設(shè)置自啟動(dòng)：
# 存儲(chǔ)庫(kù)安裝
ln -s /etc/rc.d/init.d/keepalived.init /etc/rc.d/rc3.d/S99keepalived
# 編譯安裝
mkdir /etc/keepalived
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
ln -s /usr/local/keepalived/sbin/keepalived /usr/sbin/
ln -s /usr/local/keepalived/sbin/keepalived /sbin/
# 開(kāi)啟自啟
systemctl enable keepalived
keepalived基礎(chǔ)運(yùn)行環(huán)境配置
配置/etc/host文件：
10.1.1.11 web01.test.com
10.1.1.12 web02.test.com
10.1.1.13 mysql01.test.com
10.1.1.14 mysql02.test.com
停止NetworkManager：
systemctl stop NetworkManager
systemctl disable NetworkManager
開(kāi)啟時(shí)間同步：
ntpupdate cn.ntp.org.cn
keepalived.conf詳解
! Configuration File for keepalived
#全局定義塊
global_defs {
notification_email {
acassen@firewall.loc
failover@firewall.loc
}
#指定發(fā)件人
notification_email_from smtp@test.com
#指定smtp服務(wù)器地址
smtp_server 10.1.1.200
#指定smtp連接超時(shí)時(shí)間
smtp_connect_timeout 30
#運(yùn)行keepalived機(jī)器的名稱(chēng)
router_id LVS_DEVEL
# vrrp_strict # 不注釋沒(méi)法ping通vip晓锻，需要重啟應(yīng)用
}
#VRRP實(shí)例定義塊
vrrp_instance Group1 { # 主備組名一致
#設(shè)置本機(jī)角色独撇，MASTER|BACKUP
state MASTER
#對(duì)外提供服務(wù)的網(wǎng)絡(luò)接口纷铣，要與本地的通信的接口一致
interface ens33
#VRID標(biāo)記 ,路由ID搜立，主備一致儒拂，可通過(guò)tcpdump命令查看
virtual_router_id 51
#優(yōu)先級(jí)，高優(yōu)先級(jí)競(jìng)選為master
priority 100
#健康檢查間隔命雀，默認(rèn)1秒
advert_int 1
#設(shè)置認(rèn)證
authentication {
#認(rèn)證方式
auth_type PASS
#認(rèn)證密碼
auth_pass 1qaz@WSX
}
virtual_ipaddress {
10.1.1.20 #設(shè)置vip
}
}
keepalived基本操作命令
開(kāi)啟：systemctl start keepalived
停止：systemctl stop keepalived
重啟：systemctl restart keepalived
查看狀態(tài)：systemctl status keepalived
默認(rèn)安裝目錄：/usr/local/keepalive
配置文件位置：/etc/keepalived/keepalived.conf
健康監(jiān)測(cè)nginx
編寫(xiě)一個(gè)健康監(jiān)測(cè)的腳本/sctipt/nginx.sh
#!/bin/bash
nginx_status='ps -C --no-header |wc -l'
if [ $nginx_status -eq 0 ]; then
systemctl stop keepalived
fi
在配置文件keepalived.conf中調(diào)用腳本
# 聲明腳本
vrrp_script check_nginx{
script /script/nginx.sh
interval 3
}
# 調(diào)用腳本
vrrp_instance Group1{
track_script{
check_nginx
}
}
keepalive的非搶占模式
搶占與非搶占模式：
搶占：web01故障恢復(fù)后重新?lián)屨极@取VIP
非搶占：web01故障后不再搶占獲取VIP撵儿，VIP長(zhǎng)期在web02上淀歇，直至配置更改或web02故障
如何設(shè)置非搶占模式：
1.更改配置文件為非搶占模式
vrrp_instance Group1{
nopreempt
}
2.配置state角色都為BACKUP
vrrp_instance Group1{
state BACKUP
nopreempt
}
3.重啟keepalive服務(wù)
systemctl restart keepalived
VIP腦裂
VIP腦裂的原因：最大的原因是沒(méi)有關(guān)閉防火墻，或者是防火墻沒(méi)有放通vrrp協(xié)議
抓包查看：
yum -y install tcpdump
tcpdump -i ens33 vrrp -n
可以看到正常情況下主機(jī)ip在跟vrrp組播地址通信纳决，備機(jī)不會(huì)跟組播地址過(guò)多通信阔加；如果發(fā)生腦裂所有機(jī)器都會(huì)搶占VIP胜榔，抓包查看會(huì)發(fā)現(xiàn)所有機(jī)器都跟組播地址通信。
生產(chǎn)環(huán)境防火墻放通vrrp協(xié)議：
firewall-cmd --direct --permanent --add-rule ipv4 filter INPUT 0 --in-interface ens33 --destnation 224.0.0.18 --protocol vrrp -j ACCEPT
firewall-cmd --reload
組播改單播：
先注釋vrrp_strict摔癣，接著在keepalive.conf配置文件中增加配置择浊，然后重啟應(yīng)用
# vrrp_strict
vrrp_instance Group1{
unicast_src_ip 10.1.1.11
unicast_peer {
10.1.1.12
}
}
