基于LVS负载均衡群集来实现Keepalived的部署 技术

技术文章 11个月前 完美者
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标签:讲解   热备   address   测试   evel   方案   试验   ctc   一个   

 

 

摘要

Keepalived的作用是检测服务器的状态,如果有一台web服务器宕机,或工作出现故障,Keepalived将检测到,并将有故障的服务器从系统中剔除,同时使用其他服务器代替该服务器的工作,当服务器工作正常后Keepalived自动将服务器加入到服务器群中,这些工作全部自动完成,不需要人工干涉,需要人工做的只是修复故障的服务器

一、Keepalived案例分析

1.1、企业应用中,单台服务器承担应用存在单点故障的危险

1.2、单点故障一旦发生,企业服务将发生中断,造成极大的危害

技术图片

二、Keepalived工具介绍

专为LVS和HA设计的一款健康检查工具

①支持故障自动切换(Failover)

②支持节点健康状态检查(Health Checking)

③官方网站:http://www.keepalived.org/

三、Keepalived实现原理剖析

3.1、Keepalived采用VRRP热备份协议实现Linux服务器的多机热备功能

3.2、VRRP(虚拟路由冗余协议)是针对路由器的一种备份解决方案

①由多台路由器组成一个热备组,通过共用的虚拟IP地址对外提供服务

②每个热备组内同时只有一台主路由器提供服务,其他路由器处于冗余状态

③若当前在线的路由器失效,则其他路由器会根据设置的优先级自动接替虚拟IP地址,继续提供服务

四、Keepalived案例讲解

4.1、双机热备的故障切换是由虚拟IP地址来实现,适用于各种应用服务器

4.2、实现基于Web服务的双机热备

①漂移地址:192.168.100.100

②主、备服务器:192.168.100.10、192.168.100.50

③提供的应用服务:Web

技术图片

4.3、环境(基于LVS-DR进行搭建)

虚拟IP

192.168.100.100/24

主调度器

192.168.100.10/24

备调度器

192.168.100.40/24

Web1服务器

192.168.100.20/24

Web2服务器

192.168.100.30/24

NFS共享服务器

192.168.100.50/24

客户机一台

用于测试验证

4.4、配置主调度器(192.168.100.10)

 
 1 加载ip_vs模块
 2 [root@lvs-zhu ~]# modprobe ip_vs
 3 [root@lvs-zhu ~]# cat /proc/net/ip_vs
 4 IP Virtual Server version 1.2.1 (size=4096)
 5 Prot LocalAddress:Port Scheduler Flags
 6   -> RemoteAddress:Port Forward Weight ActiveConn InActConn
 7 
 8 安装管理软件ipvsadm
 9 [root@lvs-zhu ~]# rpm -ivh /mnt/Packages/ipvsadm-1.27-7.el7.x86_64.rpm
10 
11 安装编译工具
12 [root@lvs-zhu ~]# yum -y install gcc gcc-c++ make popt-devel openssl-devel kernel-devel
13 
14 解压缩,编译安装
15 [root@lvs-zhu ~]# tar zxf keepalived-2.0.13.tar.gz
16 [root@lvs-zhu ~]# cd keepalived-2.0.13/
17 [root@lvs-zhu keepalived-2.0.13]# ./configure --prefix=/
18 [root@lvs-zhu keepalived-2.0.13]# make && make install
19 
20 加入系统管理服务,设置开机自启
21 [root@lvs-zhu keepalived-2.0.13]# cp keepalived/etc/init.d/keepalived /etc/init.d/
22 [root@lvs-zhu keepalived-2.0.13]# systemctl enable keepalived.service
23 
24 编辑配置文件
25 [root@lvs-zhu keepalived-2.0.13]# vi /etc/keepalived/keepalived.conf
26 ! Configuration File for keepalived
27 global_defs {
28       router_id LVS_01              #本服务器的名称
29 }
30 vrrp_instance VI_1 {                #定义VRRP热备实例
31       state MASTER                  #热备状态,MASTER表示主服务器,BACKUP表示从服务器
32       interface ens33               #承载VIP地址的物理接口
33       virtual_router_id 51          #虚拟路由器的ID号,每个热备组保持一致
34       priority 110                  #优先级,数值越大优先级越高
35       advert_int 1                  #通告间隔秒数(心跳频率)
36       authentication {              #热备认证信息,每个热备组保持一致
37             auth_type PASS          #认证类型
38             auth_pass 6666          #密码字符串
39       }
40       virtual_ipaddress {           #指定飘逸地址(VIP),可以有多个
41             192.168.100.100
42       }
43 }
44 virtual_server 192.168.100.100 80 {  #虚拟服务器地址(VIP)、端口
45             delay_loop 6              #健康检查的间隔时间(秒)
46             lb_algo rr                #轮询(rr)调度算法
47             lb_kind DR                #直接路由(DR)群集工作模式
48             persistence_timeout 6     #连接保持时间(秒)
49             protocol TCP              #应用服务器采用的是TCP协议
50 real_server 192.168.100.20 80 {       #第一个web服务器节点的地址、端口
51             weight 1                  #节点的权重
52             TCP_CHECK {               #健康检查方式
53             connect_port 80           #检查的目标端口
54             connect_timeout 3         #连接超时(秒)
55             nb_get_retry 3            #重试次数
56             delay_before_retry 3      #重试间隔
57             }
58 }
59 real_server 192.168.100.30 80 {
60             weight 1
61             TCP_CHECK {
62             connect_port 80
63             connect_timeout 3
64             nb_get_retry 3
65             delay_before_retry 3
66             }
67     }
68 }
69 
70 开启服务
71 [root@lvs-zhu keepalived-2.0.13]# systemctl start keepalived.service
72 [root@lvs-zhu keepalived-2.0.13]# tail -f /var/log/messages
73 [root@lvs-zhu keepalived-2.0.13]# ipvsadm -Ln
74 IP Virtual Server version 1.2.1 (size=4096)
75 Prot LocalAddress:Port Scheduler Flags
76   -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
77 TCP  192.168.100.100:80 rr persistent 6
78   -> 192.168.100.20:80            Route   1      0          0
79   -> 192.168.100.30:80            Route   1      0          0
80 [root@lvs-zhu keepalived-2.0.13]# ip addr show dev ens33
81 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
82     link/ether 00:0c:29:9a:cd:27 brd ff:ff:ff:ff:ff:ff
83     inet 192.168.100.10/24 brd 192.168.100.255 scope global ens33
84        valid_lft forever preferred_lft forever
85     inet 192.168.100.100/32 scope global ens33
86        valid_lft forever preferred_lft forever
87     inet6 fe80::26b5:ebd3:a0d2:db12/64 scope link
88        valid_lft forever preferred_lft forever
 

4.5、配置从调度器(192.168.100.40)

 
 1 加载ip_vs模块
 2 [root@lvs-bei ~]# modprobe ip_vs
 3 [root@lvs-bei ~]# cat /proc/net/ip_vs
 4 IP Virtual Server version 1.2.1 (size=4096)
 5 Prot LocalAddress:Port Scheduler Flags
 6   -> RemoteAddress:Port Forward Weight ActiveConn InActConn
 7 
 8 安装管理软件ipvsadm
 9 [root@lvs-bei ~]# rpm -ivh /mnt/Packages/ipvsadm-1.27-7.el7.x86_64.rpm
10 
11 安装编译工具
12 [root@lvs-bei ~]# yum -y install gcc gcc-c++ make popt-devel openssl-devel kernel-devel
13 
14 解压缩,编译安装
15 [root@lvs-bei ~]# tar zxf keepalived-2.0.13.tar.gz
16 [root@lvs-bei ~]# cd keepalived-2.0.13/
17 [root@lvs-bei keepalived-2.0.13]# ./configure --prefix=/
18 [root@lvs-bei keepalived-2.0.13]# make && make install
19 
20 加入系统管理服务,设置开机自启
21 [root@lvs-bei keepalived-2.0.13]# cp keepalived/etc/init.d/keepalived /etc/init.d/
22 [root@lvs-bei keepalived-2.0.13]# systemctl enable keepalived.service
23 
24 编辑配置文件
25 [root@lvs-bei keepalived-2.0.13]# vi /etc/keepalived/keepalived.conf
26 ! Configuration File for keepalived
27 global_defs {
28       router_id LVS_02              #本服务器的名称
29 }
30 vrrp_instance VI_1 {                #定义VRRP热备实例
31       state BACKUP                  #热备状态,MASTER表示主服务器,BACKUP表示从服务器
32       interface ens33               #承载VIP地址的物理接口
33       virtual_router_id 51          #虚拟路由器的ID号,每个热备组保持一致
34       priority 105                  #优先级,数值越大优先级越高
35       advert_int 1                  #通告间隔秒数(心跳频率)
36       authentication {              #热备认证信息,每个热备组保持一致
37             auth_type PASS          #认证类型
38             auth_pass 6666          #密码字符串
39       }
40       virtual_ipaddress {           #指定飘逸地址(VIP),可以有多个
41             192.168.100.100
42       }
43 }
44 virtual_server 192.168.100.100 80 {  #虚拟服务器地址(VIP)、端口
45             delay_loop 6              #健康检查的间隔时间(秒)
46             lb_algo rr                #轮询(rr)调度算法
47             lb_kind DR                #直接路由(DR)群集工作模式
48             persistence_timeout 6     #连接保持时间(秒)
49             protocol TCP              #应用服务器采用的是TCP协议
50 real_server 192.168.100.20 80 {       #第一个web服务器节点的地址、端口
51             weight 1                  #节点的权重
52             TCP_CHECK {               #健康检查方式
53             connect_port 80           #检查的目标端口
54             connect_timeout 3         #连接超时(秒)
55             nb_get_retry 3            #重试次数
56             delay_before_retry 3      #重试间隔
57             }
58 }
59 real_server 192.168.100.30 80 {
60             weight 1
61             TCP_CHECK {
62             connect_port 80
63             connect_timeout 3
64             nb_get_retry 3
65             delay_before_retry 3
66             }
67     }
68 }
69 
70 开启服务
71 [root@lvs-bei keepalived-2.0.13]# systemctl start keepalived.service
72 [root@lvs-bei keepalived-2.0.13]# tail -f /var/log/messages
73 [root@lvs-bei keepalived-2.0.13]# ipvsadm -Ln
74 IP Virtual Server version 1.2.1 (size=4096)
75 Prot LocalAddress:Port Scheduler Flags
76   -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
77 TCP  192.168.100.100:80 rr
78   -> 192.168.100.20:80            Route   1      0          0         
79   -> 192.168.100.30:80            Route   1      0          0         
80 [root@lvs-bei keepalived-2.0.13]# ip addr show dev ens33
81 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
82     link/ether 00:0c:29:dc:10:18 brd ff:ff:ff:ff:ff:ff
83     inet 192.168.100.40/24 brd 192.168.100.255 scope global ens33
84        valid_lft forever preferred_lft forever
85     inet6 fe80::c1f0:d588:3477:d684/64 scope link 
86        valid_lft forever preferred_lft forever
87 
88 ####由于设置了连接保持时间为60秒,一分钟后重新再访问该地址自动轮询交给另一台Web服务器
 

4.6、配置NFS服务器(192.168.100.50)

 
 1 安装NFS服务
 2 [root@nfs-server ~]# yum -y install rpcbind nfs-utils
 3 
 4 创建测试目录并新建网页
 5 [root@nfs-server ~]# mkdir -p /opt/web1
 6 [root@nfs-server ~]# mkdir -p /opt/web2
 7 [root@nfs-server ~]# echo ‘<h1>this is web 1!</h1>‘ > /opt/web1/index.html
 8 [root@nfs-server ~]# echo ‘<h1>this is web 2!</h1>‘ > /opt/web2/index.html
 9 
10 设置访问权限
11 [root@nfs-server ~]# vi /etc/exports
12 /opt/web1  192.168.100.20(ro)
13 /opt/web2  192.168.100.30(ro)
14 
15 开启服务并开机自启
16 [root@nfs-server ~]# systemctl start nfs
17 [root@nfs-server ~]# systemctl start rpcbind
18 [root@nfs-server ~]# systemctl enable nfs
19 [root@nfs-server ~]# systemctl enable rpcbind
20 
21 查看访问权限
22 [root@nfs-server ~]# showmount -e
23 Export list for nfs-server:
24 /opt/web2 192.168.100.30
25 /opt/web1 192.168.100.20
 

4.7 配置Web1服务器(192.168.100.20)

 
 1 安装httpd服务
 2 [root@web1 ~]# yum -y install httpd
 3 
 4 挂载NFS服务
 5 [root@web1 ~]# mount 192.168.100.50:/opt/web1 /var/www/html
 6 
 7 查看权限
 8 [root@web1 ~]# showmount -e 192.168.100.50
 9 Export list for 192.168.100.50:
10 /opt/web2 192.168.100.30
11 /opt/web1 192.168.100.20
12 
13 开启httpd服务
14 [root@web1 ~]# systemctl start httpd
15 
16 本机访问
17 [root@web1 ~]# curl http://localhost
18 <h1>this is web1!</h1>
19 
20 配置DR模式
21 [root@web1 ~]# vi web1.sh
22 #!/bin/bash
23 # web1
24 ifconfig lo:0 192.168.100.100 broadcast 192.168.100.100 netmask 255.255.255.255 up
25 route add -host 192.168.100.100 dev lo:0
26 echo "1" > /proc/sys/net/ipv4/conf/lo/arp_ignore
27 echo "1" > /proc/sys/net/ipv4/conf/all/arp_ignore
28 echo "2" > /proc/sys/net/ipv4/conf/lo/arp_announce
29 echo "2" > /proc/sys/net/ipv4/conf/all/arp_announce
30 sysctl -p &> /dev/null
31 
32 执行脚本
33 [root@web1 ~]# sh web1.sh
34 
35 查看端口信息
36 [root@web1 ~]# ifconfig
37 ......
38 lo:0: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
39         inet 192.168.100.100  netmask 255.255.255.255
40         loop  txqueuelen 1  (Local Loopback)
41 ......
 

4.8、配置web2服务器(192.168.100.30)

 
 1 安装httpd服务
 2 [root@web1 ~]# yum -y install httpd
 3 
 4 挂载NFS服务
 5 [root@web1 ~]# mount 192.168.100.50:/opt/web2 /var/www/html
 6 
 7 查看权限
 8 [root@web1 ~]# showmount -e 192.168.100.50
 9 Export list for 192.168.100.50:
10 /opt/web2 192.168.100.30
11 /opt/web1 192.168.100.20
12 
13 开启httpd服务
14 [root@web1 ~]# systemctl start httpd
15 
16 本机访问
17 [root@web1 ~]# curl http://localhost
18 <h1>this is web2!</h1>
19 
20 配置DR模式
21 [root@web1 ~]# vi web2.sh
22 #!/bin/bash
23 # web2
24 ifconfig lo:0 192.168.100.100 broadcast 192.168.100.100 netmask 255.255.255.255 up
25 route add -host 192.168.100.100 dev lo:0
26 echo "1" > /proc/sys/net/ipv4/conf/lo/arp_ignore
27 echo "1" > /proc/sys/net/ipv4/conf/all/arp_ignore
28 echo "2" > /proc/sys/net/ipv4/conf/lo/arp_announce
29 echo "2" > /proc/sys/net/ipv4/conf/all/arp_announce
30 sysctl -p &> /dev/null
31 
32 执行脚本
33 [root@web1 ~]# sh web2.sh
34 
35 查看端口信息
36 [root@web1 ~]# ifconfig
37 ......
38 lo:0: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
39         inet 192.168.100.100  netmask 255.255.255.255
40         loop  txqueuelen 1  (Local Loopback)
41 ......
 

4.9、测试web1和web2的IP访问

技术图片

 技术图片

 4.10、测试虚拟IP地址级查看状态

技术图片

 技术图片

 
1 [root@lvs-zhu keepalived-2.0.13]# ipvsadm -Ln
2 IP Virtual Server version 1.2.1 (size=4096)
3 Prot LocalAddress:Port Scheduler Flags
4   -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
5 TCP  192.168.100.100:80 rr
6   -> 192.168.100.20:80            Route   1      1          1         
7   -> 192.168.100.30:80            Route   1      1          0         
 

4.10、模拟主调度器故障,验证结果

 
 1 关闭主调度器keepalived
 2 [root@lvs-zhu keepalived-2.0.13]# systemctl stop keepalived.service
 3 
 4 查看从调度器状态
 5 [root@lvs-bei keepalived-2.0.13]# tail -f /var/log/messages
 6 [root@lvs-bei keepalived-2.0.13]# ipvsadm -Ln
 7 IP Virtual Server version 1.2.1 (size=4096)
 8 Prot LocalAddress:Port Scheduler Flags
 9   -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
10 TCP  192.168.100.100:80 rr
11   -> 192.168.100.20:80            Route   1      0          0         
12   -> 192.168.100.30:80            Route   1      0          0         
13 [root@lvs-bei keepalived-2.0.13]# ip addr show dev ens33
14 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
15     link/ether 00:0c:29:dc:10:18 brd ff:ff:ff:ff:ff:ff
16     inet 192.168.100.40/24 brd 192.168.100.255 scope global ens33
17        valid_lft forever preferred_lft forever
18     inet 192.168.100.100/32 scope global ens33
19        valid_lft forever preferred_lft forever                    #虚拟地址漂移到备调度器上
20     inet6 fe80::c1f0:d588:3477:d684/64 scope link 
21        valid_lft forever preferred_lft forever
 

技术图片

 技术图片

查看备调度器连接状态

 
1 [root@lvs-bei keepalived-2.0.13]# ipvsadm -Ln
2 IP Virtual Server version 1.2.1 (size=4096)
3 Prot LocalAddress:Port Scheduler Flags
4   -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
5 TCP  192.168.100.100:80 rr
6   -> 192.168.100.20:80            Route   1      0          1         
7   -> 192.168.100.30:80            Route   1      2          0         
 

4.11、开启主调度器并查看状态

 
 1 [root@lvs-zhu keepalived-2.0.13]# systemctl start keepalived.service 
 2 [root@lvs-zhu keepalived-2.0.13]# tail -f /var/log/messages
 3 [root@lvs-zhu keepalived-2.0.13]# ipvsadm -Ln
 4 IP Virtual Server version 1.2.1 (size=4096)
 5 Prot LocalAddress:Port Scheduler Flags
 6   -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
 7 TCP  192.168.100.100:80 rr
 8   -> 192.168.100.20:80            Route   1      0          0         
 9   -> 192.168.100.30:80            Route   1      0          0         
10 [root@lvs-zhu keepalived-2.0.13]# ip addr show dev ens33
11 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
12     link/ether 00:0c:29:9a:cd:27 brd ff:ff:ff:ff:ff:ff
13     inet 192.168.100.10/24 brd 192.168.100.255 scope global ens33
14        valid_lft forever preferred_lft forever
15     inet 192.168.100.100/32 scope global ens33
16        valid_lft forever preferred_lft forever                         #虚拟地址又到主调度器上
17     inet6 fe80::26b5:ebd3:a0d2:db12/64 scope link 
18        valid_lft forever preferred_lft forever
 

4.12、模拟web服务器故障,查看状态

①关闭web1的httpd服务

1 [root@web1 ~]# systemctl stop httpd

②测试网页,只能查看web2服务器的网页

技术图片

③查看调度器节点状态

1 [root@lvs-zhu keepalived-2.0.13]# ipvsadm -Ln
2 IP Virtual Server version 1.2.1 (size=4096)
3 Prot LocalAddress:Port Scheduler Flags
4   -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
5 TCP  192.168.100.100:80 rr
6   -> 192.168.100.30:80            Route   1      1          2         

④开启Web1服务又可以轮询了

 
1 [root@lvs-zhu keepalived-2.0.13]# ipvsadm -Ln
2 IP Virtual Server version 1.2.1 (size=4096)
3 Prot LocalAddress:Port Scheduler Flags
4   -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
5 TCP  192.168.100.100:80 rr
6   -> 192.168.100.20:80            Route   1      2          0         
7   -> 192.168.100.30:80            Route   1      3          1         
 

总结

通过本篇文章学习了Keepalived的群集部署,故障时是如何自动切换以及节点健康检查的方式

基于LVS负载均衡群集来实现Keepalived的部署 技术

标签:讲解   热备   address   测试   evel   方案   试验   ctc   一个   

原文地址:https://www.cnblogs.com/wqhao/p/13936494.html

版权声明:完美者 发表于 2020-11-07 16:15:30。
转载请注明:基于LVS负载均衡群集来实现Keepalived的部署 技术 | 完美导航

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