HA(高可用)Cluster实现

  • 来源:网络
  • 更新日期:2020-08-14

摘要:建站服务器 HA Cluster的目的,为了防止重要的服务器在提供服务时,出现不可抗力的因素,例如硬件故障自然灾害,断电,软件bug,操作系统bug等,导致提

建站服务器

HA Cluster的目的,为了防止重要的服务器在提供服务时,出现不可抗力的因素,例如硬件故障

自然灾害,断电,软件bug,操作系统bug等,导致提供服务的主机出现宕机,死机,从而影响正

常业务,因此采用高可用的方案,实现持续性稳定的提供主机服务的方案称为HA

A=可用

MTBF=平均无故障时间

MTTR=平均修复时长

换算公式

A=MTBF/(MTBF+MTTR)

注意提升A值的方法:

1.分子足够大,但是不划算,成本太高

2.降低分母,即降低平均修复时长,成本较低效果出色

如何降低平均修复时长?

建立备用服务器,实现Failover功能。

原理:在主服务器发生故障时,快速转移IP地址(floating ip),以及快速转移应用程序至备用服务器

需要相关软件转移IP(转移IP即实现ip地址从新配置),转移服务(即在备用主机上启动相关服务应用程序)

总体来说HA 即为在主服务器宕机时,实现备用服务器的快速切换

关键点:IP地址转移,数据共享

HA Cluster (ip,nginx)ip与nginx进程通常称为HA资源


备用服务器使用“心跳”检测,向主服务器发起udp报文(UDP报文不需要三次握手等),

根据主服务器的响应来判断主服务器是否正常工作

关键点:响应时间,资源争用共享存储

假如链接主从服务器的网线连接中断,则会导致,ip争夺,而且最主要的是存储的混乱(同一文件

一边在增加,另一边再删除)

会导致源数据的损坏,损害很大,解决方法,使用爆头设备(STONITH),在补刀,将未彻底断电的还在运行设备断电

当处理完主服务器的故障后,还要将服务器上线,即为Failback

Failover<------->Failback


HA Cluster实现方案

1、vrrp协议的实现

keepalived

2、ais(available Interface standard):可用接口标准,完备HA集群

RHCS(cmam)

heartbeat

corosync


Keepalived:

vrrp协议:Virtual Redundant Protocol

术语:

虚拟路由:virtual router

虚拟路由器标识:VRID(0-255)

物理路由:

master:主设备

back:备用设备

priority:优先级

VIP:virtual Ip

VMAC:Virtual MAC (00-00-5e-00-01-VRID)

GraciousARP(免费arp)

通告:心跳,优先级等;周期性;

抢占式,非抢占式;

安全工作:

   认证:

无认证

简单字符认证

MD5

工作模式

主/备:单虚拟路由器;

主/主:主/备(虚拟路由器1),备/主(虚拟路径器2)

特点:

vrrp协议的软件实现,原生设计的目的为了高可用ipvs服务:

vrrp协议完成地址流动;

为vip地址所在的节点生成ipvs规则(在配置文件中预先定义);

为ipvs集群的各RS做健康状态检测;

基于脚本调用接口通过执行脚本完成脚本中定义的功能,进而影响集群事务;

组件:

核心组件:

vrrp stack

ipvs wrapper

checkers

控制组件:配置文件分析器

IO复用器

内存管理组件

HA Cluster的配置前提:

(1)各节点时间必须同步

(2)确保iptables及selinux不会成为阻碍;

(3)各节点之间可通过主机名互相通信(对KA并非必须);

建议使用/etc/hosts文件实现;

(4)各节点之间的root用户可以基于密钥认证的ssh服务完成互相通信(并非必须)

keepalived安装配置:

CentOS 6.4+随base仓库提供;

1、同步时间

配置chronyd服务器172.18。200.100

yum安装chrony,并启动服务

[root@localhost ~]# service chronyd start

Starting chronyd:                                          [  OK  ]


使用ntpdate命令,同步172.18.10.10以及172.18.10.11的时间

[root@localhost ~]# ntpdate 172.18.200.100

2、清空iptables和selinux

iptables -F

setenforce 0

3、配置hosts文件(非必须)

4、安装keepalived

[root@localhost ~]# yum install keepalived

[root@localhost ~]# cd /etc/keepalived/

[root@localhost keepalived]# ls

keepalived.conf

[root@localhost keepalived]# cp keepalived.conf keepalived.conf.bak

[root@localhost keepalived]# ls

keepalived.conf  keepalived.conf.bak

[root@localhost keepalived]# vim keepalived.conf

主配置文件:/etc/keepalived/keepalived.conf

配置文件组成部分及相关选项解释

TOP HIERACHY

GLOBAL CONFIGURATION

Global definitions

Static routes/addresses

VRRPD CONFIGURATION

VRRP synchronization group(s):vrrp同步组;

VRRP instance(s):每个vrrp instance即一个vrrp路由器;

LVS CONFIGURATION

Virtual server group(s)

Virtual server(s):ipvs集群的vs和rs;

global_defs {    ###全局定义

   notification_email {

     acassen@firewall.loc

     failover@firewall.loc  ####定义出现问题后发送邮箱的地址

     sysadmin@firewall.loc

   }

   notification_email_from Alexandre.Cassen@firewall.loc   ##从哪里发过来

   smtp_server 192.168.200.1  ###邮件服务器地址

   smtp_connect_timeout 30#####超时时间

   router_id LVS_DEVEL###路由器IP

   vrrp_mcast_group4  224.0.100.5###ipv4多播地址


}


vrrp_instance VI_1 {  ##vrrp配置段

    state MASTER###表示是主还是从这里显示主,另一个则为从

    interface eth0###表明工作从哪个网卡发出 “多波心跳信息”

    virtual_router_id 51###虚拟路由ID

    priority 100###主的优先级

    advert_int 1       ##通告时间间隔

    authentication###认证

        auth_type PASS####认证类型:简单密钥认证

        auth_pass 1111#####认证密码:最多不能超过8位

    }

    virtual_ipaddress {##虚拟IP地址配在哪个网卡上

        192.168.200.16/24 dev eth0   ##定义配置在哪个网卡的别名上

        192.168.200.17

        192.168.200.18

    }

}

track_interface {   ##配置要监控的网络接口,一旦接口出现故障,则转为FAULT状态;即接口跟踪

eth0

eth2

...

}

nopreempt:定义工作模式为非抢占模式;

preempt_delay 300:抢占式模式下,节点上线后触发新选举操作的延迟时长;

5、修改配置文件

[root@localhost keepalived]# vim keepalived.conf

global_defs {

   notification_email {

        root@localhost

   }

   notification_email_from keepalived@localhost

   smtp_server 127.0.0.1

   smtp_connect_timeout 30

   router_id node1

   vrrp_mcast_group4  224.0.100.50

}


vrrp_instance myroute {

    state MASTER

    interface eth2

    virtual_router_id 50

    priority 100

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 123456

    }

    virtual_ipaddress {

        172.18.50.50/16 dev eth2

    }

}

6、将配置文件发送到另一台机器10上

[root@localhost keepalived]# scp keepalived.conf 172.18.10.10:/etc/keepalived/

修改配置文件

[root@localhost keepalived]# vim keepalived.conf

global_defs {

   notification_email {

        root@localhost

   }

   notification_email_from keepalived@localhost

   smtp_server 127.0.0.1

   smtp_connect_timeout 30

   router_id node2

   vrrp_mcast_group4  224.0.100.50

}


vrrp_instance myroute {

    state BACKUP

    interface eth2

    virtual_router_id 50

    priority 98

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 123456

    }

    virtual_ipaddress {

        172.18.50.50/16 dev eth2

    }

}


7、启动服务

启动备用服务器11

[root@localhost ~]# service keepalived start

查看地址

[root@localhost ~]# ip a

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: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

    link/ether 00:0c:29:07:27:ff brd ff:ff:ff:ff:ff:ff

    inet 172.18.10.10/16 brd 172.18.255.255 scope global eth2

    inet 172.18.50.50/16 scope global secondary eth2

    inet6 fe80::20c:29ff:fe07:27ff/64 scope link 

       valid_lft forever preferred_lft forever

发现地址已经添加,这是若开启主服务器,由于没有设置抢断延迟,则会立刻抢断

8、启动主服务器

[root@localhost keepalived]# service keepalived start

Starting keepalived:                                       [  OK  ]

[root@localhost keepalived]# ip a

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: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

    link/ether 00:0c:29:99:76:84 brd ff:ff:ff:ff:ff:ff

    inet 172.18.10.11/16 brd 172.18.255.255 scope global eth2

    inet 172.18.50.50/16 scope global secondary eth2

    inet6 fe80::20c:29ff:fe99:7684/64 scope link 

       valid_lft forever preferred_lft forever

发现地址已经添加

而从服务器11上

[root@localhost ~]# ip a

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: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

    link/ether 00:0c:29:07:27:ff brd ff:ff:ff:ff:ff:ff

    inet 172.18.10.10/16 brd 172.18.255.255 scope global eth2

    inet6 fe80::20c:29ff:fe07:27ff/64 scope link 

       valid_lft forever preferred_lft forever

IP地址已经删除

9、使用tcpdump抓包工具查看主从服务器的相应心跳测试

[root@localhost keepalived]# tcpdump -i eth2 host 224.0.100.50   ###在主服务器端抓包

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

listening on eth2, link-type EN10MB (Ethernet), capture size 65535 bytes

16:39:33.357307 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:34.358905 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:35.360605 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:36.362301 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:37.363904 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:38.365658 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:39.367266 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:40.368921 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:41.370599 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

[root@localhost ~]#  tcpdump -i  eth2  -nn host 224.0.100.50   ###在从服务器端抓包

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

listening on eth2, link-type EN10MB (Ethernet), capture size 65535 bytes

16:39:40.367044 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:41.368741 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:42.370289 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:43.371983 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:44.373750 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:45.375413 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:46.377092 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

16:39:47.378760 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

分析说明。实现简单的vrrp

即从服务器每隔一秒向主服务器发送1个通报报文。探测主服务器是否存活,实现具体实施软件keepalived

###############################################################################################################################

双主模型


1、我们在172.18.10.11上配置了主服务器配置,双主服务可在配置文件下面继续添如下内容,配置如下

[root@localhost keepalived]# vim keepalived.conf

vrrp_instance myroute2 {

    state BACKUP

    interface eth2

    virtual_router_id 51

    priority 98

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 123457

    }

    virtual_ipaddress {

        172.18.51.51/16 dev eth2

    }

}

2、将内容服务至粘贴至172.18.10.10服务器的keepalived.conf配置文件中,然后需要在state和priority上进行相应修改

vrrp_instance myroute2 {

    state MASTER

    interface eth2

    virtual_router_id 51

    priority 100

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 123457

    }

    virtual_ipaddress {

        172.18.51.51/16 dev eth2

    }

}

保存并退出,实现双主模型的设置


3、从启服务并测试

service keepalived restart

Stopping keepalived:                                       [  OK  ]

Starting keepalived:                                       [  OK  ]

使用tcpdump抓包,结果如下

172.18.10.11端

[root@localhost keepalived]#  tcpdump -i  eth2  -nn host 224.0.100.50

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

listening on eth2, link-type EN10MB (Ethernet), capture size 65535 bytes

00:50:20.150330 IP 172.18.10.10 > 224.0.100.50: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20

00:50:20.521639 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

00:50:21.151175 IP 172.18.10.10 > 224.0.100.50: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20

00:50:21.522539 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

00:50:22.152517 IP 172.18.10.10 > 224.0.100.50: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20

00:50:22.523232 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

00:50:23.154334 IP 172.18.10.10 > 224.0.100.50: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20

00:50:23.524046 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

172.18.10.10端

[root@localhost keepalived]# tcpdump -i eth2 host 224.0.100.50

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

listening on eth2, link-type EN10MB (Ethernet), capture size 65535 bytes

00:54:01.436075 IP 172.18.10.10 > 224.0.100.50: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20

00:54:01.437266 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

00:54:02.437295 IP 172.18.10.10 > 224.0.100.50: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20

00:54:02.438831 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

00:54:03.438695 IP 172.18.10.10 > 224.0.100.50: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20

00:54:03.439205 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20


分析每次都会收到两次信息,一次发送,一次接收

使用iptable设置规则,拒绝172.18.10.11向224.0.100.50发送通知报文

[root@localhost keepalived]# iptables -A OUTPUT -s 172.18.10.11 -d 224.0.100.50 -j REJECT

在172.18.10.10端使用tcpdump抓包

[root@localhost keepalived]#  tcpdump -i  eth2  -nn host 224.0.100.50

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

listening on eth2, link-type EN10MB (Ethernet), capture size 65535 bytes

00:50:20.150330 IP 172.18.10.10 > 224.0.100.50: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20

00:50:20.521639 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

00:50:21.151175 IP 172.18.10.10 > 224.0.100.50: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20

00:50:21.522539 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

00:50:22.152517 IP 172.18.10.10 > 224.0.100.50: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20

00:50:22.523232 IP 172.18.10.11 > 224.0.100.50: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

分析发现发送两条通告,因为172.18.10.11不通告,便认为172.18.10.11挂掉了,因此抢断,让自己变为主机。即别人不通告则认为对方挂掉了

可以使用ip a l 查看相应的ip地址获取:

[root@localhost keepalived]# ip a l

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: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

    link/ether 00:0c:29:07:27:ff brd ff:ff:ff:ff:ff:ff

    inet 172.18.10.10/16 brd 172.18.255.255 scope global eth2

    inet 172.18.51.51/16 scope global secondary eth2

    inet 172.18.50.50/16 scope global secondary eth2

    inet6 fe80::20c:29ff:fe07:27ff/64 scope link 

       valid_lft forever preferred_lft forever

再次在172.18.10.11服务器上,清空iptables规则

[root@localhost keepalived]# iptables -F

再回到172.18.10.10服务器上使用ip a l 查询

[root@localhost keepalived]# ip a l

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: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

    link/ether 00:0c:29:07:27:ff brd ff:ff:ff:ff:ff:ff

    inet 172.18.10.10/16 brd 172.18.255.255 scope global eth2

    inet 172.18.51.51/16 scope global secondary eth2

    inet6 fe80::20c:29ff:fe07:27ff/64 scope link 

       valid_lft forever preferred_lft forever

发现地址已经立马被夺回,是因为工作在抢占模式下。没有设置preempt_delay 300抢占延迟时间,

结论:实现双主模型实验


##################################################################################################################


如何实现自定义通知脚本


一、在172.18.10.11服务器上添加脚本,实现自动发邮件

1.编写邮件脚本

vim notify.sh

#!/bin/bash

#

contact=\'root@localhost\'


notify() {

        mailsubject=vrrp: $(hostname) to be $1

        mailbody=$(hostname) to be $1,vrrp transition, $(date).

        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

        exit 1

        ;;

esac

      

2、测试脚本

语法检测

[root@localhost keepalived]# bash -n notify.sh

运行脚本测试

[root@localhost keepalived]# bash -x notify.sh master

+ contact=root@localhost

+ case $1 in

+ notify master

++ hostname

+ mailsubject=\'localhost.localdomain to be master\'

++ hostname

++ date

+ mailbody=\'localhost.localdomain to be master,vrrp transition, Mon May 15 01:36:33 CST 2017.\'

+ echo \'localhost.localdomain to be master,vrrp transition, Mon May 15 01:36:33 CST 2017.\'

+ mail -s mailsubject root@localhost

[root@localhost keepalived]# vim notify.sh

You have mail in /var/spool/mail/root


3、查看收到的邮件


[root@localhost keepalived]# mail

Heirloom Mail version 12.4 7/29/08.  Type ? for help.

/var/spool/mail/root: 1 message 1 new

>N  1 root                  Mon May 15 01:36  18/696   mailsubject

&     

Message  1:

From root@localhost.localdomain  Mon May 15 01:36:34 2017

Return-Path: <root@localhost.localdomain>

X-Original-To: root@localhost

Delivered-To: root@localhost.localdomain

Date: Mon, 15 May 2017 01:36:33 +0800

To: root@localhost.localdomain

Subject: mailsubject

User-Agent: Heirloom mailx 12.4 7/29/08

Content-Type: text/plain; charset=us-ascii

From: root@localhost.localdomain (root)

Status: R


localhost.localdomain to be master,vrrp transition, Mon May 15 01:36:33 CST 2017.


4、将脚本发送至172.18.10.10端


[root@localhost keepalived]# scp notify.sh 172.18.10.10:/etc/keepalived/

root@172.18.10.10\'s password: 

notify.sh                                                                       100%  367     0.4KB/s   00:00


5、调用脚本


[root@localhost keepalived]# vim keepalived.conf

在172.18.10.11上的vrrp_instance myrouter1下面添加如下内容,注意是放在vrrp_instance myrouter1上下文中调用


        notify_master /etc/keepalived/notify.sh master

        notify_backup /etc/keepalived/notify.sh backup

        notify_fault /etc/keepalived/notify.sh fault

在172.18.10.10上的vrrp_instance myrouter2下面添加如下内容


        notify_master /etc/keepalived/notify.sh master

        notify_backup /etc/keepalived/notify.sh backup

        notify_fault /etc/keepalived/notify.sh fault


6,为了实现测试效果,将之前定义的双主模型删除,并停止服务(在10.10和10.11上做同样的操作)

:.,$d  表示从当前行都最后一行全部删除


[root@localhost keepalived]# service keepalived stop

Stopping keepalived:                                       [  OK  ]


7、给之前编写的脚本加上执行权限

[root@localhost keepalived]# chmod +x  notify.sh 

[root@localhost keepalived]# ll

total 8

-rw-r--r-- 1 root root 658 May 15 02:01 keepalived.conf

-rwxr-xr-x 1 root root 367 May 15 01:41 notify.sh


8、启动服务

在172.18.10.11端

[root@localhost keepalived]# service keepalived start

Starting keepalived:                                       [  OK  ]

[root@localhost keepalived]# ip a l

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: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

    link/ether 00:0c:29:99:76:84 brd ff:ff:ff:ff:ff:ff

    inet 172.18.10.11/16 brd 172.18.255.255 scope global eth2

    inet 172.18.50.50/16 scope global secondary eth2

    inet6 fe80::20c:29ff:fe99:7684/64 scope link 

       valid_lft forever preferred_lft forever

[root@localhost keepalived]# mail

Heirloom Mail version 12.4 7/29/08.  Type ? for help.

/var/spool/mail/root: 3 messages 2 unread

    1 root                  Mon May 15 01:36  19/707   mailsubject

>U  2 root                  Mon May 15 11:03  19/735   vrrp: localhost.localdomain to be master

9、启动172.18.10.10端的keepalived,并且再次到172.18.10.11端查看邮件

[root@localhost ~]# mail

Heirloom Mail version 12.4 7/29/08.  Type ? for help.

/var/spool/mail/root: 7 messages 5 new 7 unread

 U  1 root                  Mon May 15 11:09  19/735   vrrp: localhost.localdomain to be backup

 U  2 root                  Mon May 15 11:11  19/735   vrrp: localhost.localdomain to be backup

>N  3 root                  Mon May 15 11:11  18/725   vrrp: localhost.localdomain to be master

 N  4 root                  Mon May 15 11:11  18/725   vrrp: localhost.localdomain to be backup

 N  5 root                  Mon May 15 11:26  18/725   vrrp: localhost.localdomain to be backup

 N  6 root                  Mon May 15 11:26  18/725   vrrp: localhost.localdomain to be master

 N  7 root                  Mon May 15 11:26  18/725   vrrp: localhost.localdomain to be backup

结论:通知脚本功能实现

######################################################################################################


如何实现 keepalived 高可用LVS (重点)


实验准备:4台虚拟主机

其中172.18.10.10和172.18.10.11做为VS端分别为VS2和VS1

172.18.200.100和172.18.249.57做为RS分别为RS1和RS2

首先分别再RS1和RS2端安装httpd


1、进行如下配置


[root@localhost ~]# cat /var/www/html/index.html

<h2>RS1:172.18.200.100</h2>

[root@localhost ~]# cat /var/www/html/index.html 

<h2>RS2:172.18.249.57</h2>


2、编写VIP配置脚本

vim setparam.sh

#!/bin/bash

#

vip=\'172.18.50.50\'

netmask=\'255.255.255.255\'

iface=\'lo:0\'


case $1 in

start)

        echo 1 > /pro/sys/net/ipv4/conf/all/arp_ignore

        echo 1 > /pro/sys/net/ipv4/conf/lo/arp_ignore

        echo 2 > /pro/sys/net/ipv4/conf/all/arp_ignore

        echo 2 > /pro/sys/net/ipv4/conf/lo/arp_ignore

        ifconfig $iface $vip netmask $netmask broadcast $vip up

        route add -host $vip dev $iface

        ;;

stop)

        ifconfig $iface down

        echo 0 > /pro/sys/net/ipv4/conf/all/arp_ignore

        echo 0 > /pro/sys/net/ipv4/conf/lo/arp_ignore

        echo 0 > /pro/sys/net/ipv4/conf/all/arp_ignore

        echo 0 > /pro/sys/net/ipv4/conf/lo/arp_ignore

        ;;

esac


3、测试脚本

[root@localhost ~]# bash -n setparam.sh 

[root@localhost ~]# bash -x setparam.sh start

+ vip=172.18.50.50

+ netmask=255.255.255.255

+ iface=lo:0

+ case $1 in

+ echo 1

setparam.sh: line 9: /pro/sys/net/ipv4/conf/all/arp_ignore: No such file or directory

+ echo 1

setparam.sh: line 10: /pro/sys/net/ipv4/conf/lo/arp_ignore: No such file or directory

+ echo 2

setparam.sh: line 11: /pro/sys/net/ipv4/conf/all/arp_announce: No such file or directory

+ echo 2

setparam.sh: line 12: /pro/sys/net/ipv4/conf/lo/arp_announce: No such file or directory

+ ifconfig lo:0 172.18.50.50 netmask 255.255.255.255 broadcast 172.18.50.50 up

+ route add -host 172.18.50.50 dev lo:0


4、使用scp将脚本分发至RS2

[root@localhost ~]# scp setparam.sh 172.18.249.57:/root

root@172.18.249.57\'s password: 

setparam.sh                                                                                  100%  610     0.6KB/s   00:00 


5、在RS2端执行脚本,并查看是否生成VIP

[root@localhost ~]# bash -x setparam.sh start

+ vip=172.18.50.50

+ netmask=255.255.255.255

+ iface=lo:0

+ case $1 in

+ echo 1

setparam.sh: line 9: /pro/sys/net/ipv4/conf/all/arp_ignore: No such file or directory

+ echo 1

setparam.sh: line 10: /pro/sys/net/ipv4/conf/lo/arp_ignore: No such file or directory

+ echo 2

setparam.sh: line 11: /pro/sys/net/ipv4/conf/all/arp_announce: No such file or directory

+ echo 2

setparam.sh: line 12: /pro/sys/net/ipv4/conf/lo/arp_announce: No such file or directory

+ ifconfig lo:0 172.18.50.50 netmask 255.255.255.255 broadcast 172.18.50.50 up

+ route add -host 172.18.50.50 dev lo:0

[root@localhost ~]# ip a

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

    inet 172.18.50.50/32 brd 172.18.50.50 scope global lo:0

    inet6 ::1/128 scope host 

       valid_lft forever preferred_lft forever

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

    link/ether 00:0c:29:b2:ca:ea brd ff:ff:ff:ff:ff:ff

    inet 172.18.249.57/16 brd 172.18.255.255 scope global eth0

    inet6 fe80::20c:29ff:feb2:caea/64 scope link 

       valid_lft forever preferred_lft forever


6、启动RS1和RS2的httpd服务,并查看端口,两端都要查看,这里只演示一端的

[root@localhost ~]# service httpd start

[root@localhost ~]# ss -tnl

State       Recv-Q Send-Q                               Local Address:Port                                 Peer Address:Port 

LISTEN      0      128                                             :::80                                             :::*     

LISTEN      0      128                                             :::22                                             :::*     

LISTEN      0      128                                              *:22                                              *:*     

LISTEN      0      100                                            ::1:25                                             :::*     

LISTEN      0      100                                      127.0.0.1:25       


7、在两个前段节点生成ipvs规则

在VS2端

停止keepalived服务

配置sorry server页面

vim /var/www/html/index.html

Director2 sorry server2


启动httpd服务

[root@localhost ~]# service httpd start


在VS1端

首先停止keepalived服务

[root@localhost ~]#  service keepalived stop  

vim /var/www/html/index.html

Director1


启动httpd服务

[root@localhost ~]# service httpd start


在VS1端编辑keepalived配置文件,添加如下内容:

virtual_server 172.18.50.50 80 {

    delay_loop 6

    lb_algo wrr

    lb_kind DR

    persistence_timeout 0

    protocol TCP


    real_server 172.18.10.11 80 {

        weight 1

        HTTP_GET {

    persistence_timeout 0

    protocol TCP

sorry_server 127.0.0.1 80


    real_server 172.18.10.11 80 {

        weight 1

        HTTP_GET {

            url {

              path /

                status_code 200

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

    real_server 172.18.10.10 80 {

        weight 1

        HTTP_GET {

            url {

              path /

                status_code 200

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

}


在VS2端,同样编辑keepalived.conf文件,添加如下内容

virtual_server 172.18.50.50 80 {

    delay_loop 6

    lb_algo wrr

    lb_kind DR

    persistence_timeout 0

    protocol TCP

sorry_server 127.0.0.1 80

    real_server 172.18.10.11 80 {

        weight 1

        HTTP_GET {

    persistence_timeout 0

    protocol TCP


    real_server 172.18.10.11 80 {

        weight 1

        HTTP_GET {

            url {

              path /

                status_code 200

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

    real_server 172.18.10.10 80 {

        weight 1

        HTTP_GET {

            url {

              path /

                status_code 200

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

}

在VS2上启动keepalived服务

[root@localhost ~]# service keepalived start

Starting keepalived:                                       [  OK  ]

[root@localhost ~]# ipvsadm -ln

IP Virtual Server version 1.2.1 (size=4096)

Prot LocalAddress:Port Scheduler Flags

  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn

TCP  172.18.50.50:80 wrr

  -> 172.18.200.100:80            Route   1      0          0         

  -> 172.18.249.57:80             Route   1      0          0   


在客户端使用curl进行访问测试(配置完有一定延迟,稍等片刻在访问)

[root@localhost ~]# curl http://172.18.50.50

<h2>RS2:172.18.249.57</h2>

[root@localhost ~]# curl http://172.18.50.50

<h2>RS1:172.18.200.100</h2>

[root@localhost ~]# curl http://172.18.50.50

<h2>RS2:172.18.249.57</h2>

[root@localhost ~]# curl http://172.18.50.50

<h2>RS1:172.18.200.100</h2>

[root@localhost ~]# curl http://172.18.50.50

<h2>RS2:172.18.249.57</h2>

[root@localhost ~]# curl http://172.18.50.50

<h2>RS1:172.18.200.100</h2>

[root@localhost ~]# curl http://172.18.50.50

<h2>RS2:172.18.249.57</h2>

[root@localhost ~]# curl http://172.18.50.50

<h2>RS1:172.18.200.100</h2>


在172.18.200.100端停止httpd服务

[root@localhost ~]# service httpd stop

Stopping httpd:                                            [  OK  ]


在VS2端使用ipvsadm观察

[root@localhost keepalived]# ipvsadm -ln

IP Virtual Server version 1.2.1 (size=4096)

Prot LocalAddress:Port Scheduler Flags

  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn

TCP  172.18.50.50:80 wrr

  -> 172.18.249.57:80             Route   1      0          2  


在172.18.200.100端停止httpd服务

[root@localhost ~]# service httpd start


在VS2端使用ipvsadm观察

[root@localhost keepalived]# ipvsadm -ln

IP Virtual Server version 1.2.1 (size=4096)

Prot LocalAddress:Port Scheduler Flags

  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn

TCP  172.18.50.50:80 wrr

  -> 172.18.200.100:80            Route   1      0          0         

  -> 172.18.249.57:80             Route   1      0          0    


启动VS1上的keepalived服务,并且关闭VS2,客户端使用curl测试发现,仍然能够访问

[root@localhost keepalived]# curl http://172.18.50.50

<h2>RS2:172.18.249.57</h2>

[root@localhost keepalived]# curl http://172.18.50.50

<h2>RS1:172.18.200.100</h2>

[root@localhost keepalived]# curl http://172.18.50.50

<h2>RS2:172.18.249.57</h2>

[root@localhost keepalived]# curl http://172.18.50.50

<h2>RS1:172.18.200.100</h2>


更改配置文件,将之前删除的双主内容添加进去

VS1端

vrrp_instance myroute2 {

    state BACKUP

    interface eth2

    virtual_router_id 51

    priority 98

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 123457

    }

    virtual_ipaddress {

172.18.51.51/16 dev eth2

    }

}

VS2端

vrrp_instance myroute2 {

    state MASTER

    interface eth2

    virtual_router_id 51

    priority 98

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 123457

    }

    virtual_ipaddress {

172.18.51.51/16 dev eth2

    }

}



重启keepalived服务,相当重要,,,,,不重启不会有效果,这就是个坑




总结VS端

VS2端keepalived配置

! Configuration File for keepalived


global_defs {

   notification_email {

root@localhost

   }

   notification_email_from keepalived@localhost

   smtp_server 127.0.0.1

   smtp_connect_timeout 30

   router_id node2

   vrrp_mcast_group4  224.0.100.50

}


vrrp_instance myroute1 {

    state BACKUP

    interface eth2

    virtual_router_id 50

    priority 98

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 123456

    }

    virtual_ipaddress {

172.18.50.50/16 dev eth2

    }


notify_master /etc/keepalived/notify.sh master

notify_backup /etc/keepalived/notify.sh backup

notify_fault /etc/keepalived/notify.sh fault

}


vrrp_instance myroute2 {

    state MASTER

    interface eth2

    virtual_router_id 51

    priority 98

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 123457

    }

    virtual_ipaddress {

172.18.51.51/16 dev eth2

    }

}


virtual_server 172.18.50.50 80 {

    delay_loop 6

    lb_algo wrr

    lb_kind DR

    persistence_timeout 0

    protocol TCP

    sorry_server 127.0.0.1 80


    real_server 172.18.200.100 80 {

        weight 1

        HTTP_GET {

            url {

              path /

                status_code 200

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

    real_server 172.18.249.57 80 {

        weight 1

        HTTP_GET {

            url {

              path /

                status_code 200

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

}


virtual_server 172.18.51.51 80 {

    delay_loop 6

    lb_algo wrr

    lb_kind DR

    persistence_timeout 0

    protocol TCP

    sorry_server 127.0.0.1 80


    real_server 172.18.200.100 80 {

        weight 1

        HTTP_GET {

            url {

              path /

                status_code 200

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

    real_server 172.18.249.57 80 {

        weight 1

        HTTP_GET {

            url {

              path /

                status_code 200

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

}


VS1端keepalived配置

! Configuration File for keepalived


global_defs {

   notification_email {

root@localhost

   }

   notification_email_from keepalived@localhost

   smtp_server 127.0.0.1

   smtp_connect_timeout 30

   router_id node1

   vrrp_mcast_group4  224.0.100.50

}


vrrp_instance myroute1 {

    state MASTER

    interface eth2

    virtual_router_id 50

    priority 100

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 123456

    }

    virtual_ipaddress {

172.18.50.50/16 dev eth2

    }


notify_master /etc/keepalived/notify.sh master

        notify_backup /etc/keepalived/notify.sh backup

        notify_fault /etc/keepalived/notify.sh fault

}


vrrp_instance myroute2 {

    state BACKUP

    interface eth2

    virtual_router_id 51

    priority 98

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 123457

    }

    virtual_ipaddress {

172.18.51.51/16 dev eth2

    }

}



virtual_server 172.18.50.50 80 {

    delay_loop 6

    lb_algo wrr

    lb_kind DR

    persistence_timeout 0

    protocol TCP

sorry_server 127.0.0.1 80


    real_server 172.18.200.100 80 {

        weight 1

        HTTP_GET {

            url {

              path /

status_code 200

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

    real_server 172.18.249.57 80 {

        weight 1

        HTTP_GET {

            url {

              path /

status_code 200

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

}


virtual_server 172.18.51.51 80 {

    delay_loop 6

    lb_algo wrr

    lb_kind DR

    persistence_timeout 0

    protocol TCP

sorry_server 127.0.0.1 80


    real_server 172.18.200.100 80 {

        weight 1

        HTTP_GET {

            url {

              path /

status_code 200

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

    real_server 172.18.249.57 80 {

        weight 1

        HTTP_GET {

            url {

              path /

status_code 200

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

}


VIP配置脚本 (由用户是双主模型因此VIP有两个)

#!/bin/bash

#

vip=\'172.18.50.50\'

vip2=\'172.18.51.51\'

netmask=\'255.255.255.255\'

iface=\'lo:0\'

iface2=\'lo:1\'


case $1 in

start)

echo 1 > /pro/sys/net/ipv4/conf/all/arp_ignore

echo 1 > /pro/sys/net/ipv4/conf/lo/arp_ignore

echo 2 > /pro/sys/net/ipv4/conf/all/arp_announce

echo 2 > /pro/sys/net/ipv4/conf/lo/arp_announce

ifconfig $iface $vip netmask $netmask broadcast $vip up

ifconfig $iface2 $vip2 netmask $netmask broadcast $vip2 up

route add -host $vip dev $iface

;;

stop)

ifconfig $iface down

ifconfig $iface2 down

echo 0 > /pro/sys/net/ipv4/conf/all/arp_ignore

echo 0 > /pro/sys/net/ipv4/conf/lo/arp_ignore

echo 0 > /pro/sys/net/ipv4/conf/all/arp_announce

echo 0 > /pro/sys/net/ipv4/conf/lo/arp_announce

;;

esac


实验结论:实现keepalived 高可用lvs负载均衡





















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