linux中的keeplived源码装,Linux下安装Keepalived及原理分析

keepalived是集群管理中保证集群高可用的一个服务软件&＃xff0c;其功能类似于heartbeat&＃xff0c;用来防止单点故障。

2、keepalived工作原理

keepalived是以VRRP协议为实现基础的&＃xff0c;VRRP全称Virtual Router Redundancy Protocol&＃xff0c;即虚拟路由冗余协议。

虚拟路由冗余协议&＃xff0c;可以认为是实现路由器高可用的协议&＃xff0c;即将N台提供相同功能的路由器组成一个路由器组&＃xff0c;这个组里面有一个master和多个backup&＃xff0c;master上面有一个对外提供服务的vip(该路由器所在局域网内其他机器的默认路由为该vip)&＃xff0c;master会发组播&＃xff0c;当backup收不到vrrp包时就认为master宕掉了&＃xff0c;这时就需要根据VRRP的优先级来选举一个backup当master。这样的话就可以保证路由器的高可用了。

keepalived主要有三个模块&＃xff0c;分别是core、check和vrrp。core模块为keepalived的核心&＃xff0c;负责主进程的启动、维护以及全局配置文件的加载和解析。check负责健康检查&＃xff0c;包括常见的各种检查方式。vrrp模块是来实现VRRP协议的。

3、keepalived的配置文件

keepalived只有一个配置文件keepalived.conf&＃xff0c;里面主要包括以下几个配置区域&＃xff0c;分别是global_defs、static_ipaddress、static_routes、vrrp_script、vrrp_instance和virtual_server

2、keepalived 在Linux下的安装

1、准备工作

Linux主机&＃xff1a;10.122.111.80 、

Linux主机&＃xff1a;10.122.111.81、

虚拟IP&＃xff1a;10.122.111.99、

操作系统&＃xff1a;银河麒麟 V3.3

2、安装Keepalived

两台Linux主机都需要安装Keepalived&＃xff0c;如下步骤两台机需要重复进行。

1、下载Keepalived

下载至目录&＃xff1a;/home/zz/user/software

wget

2、解压Keepalived

tar -zxvf keepalived-1.3.8.tar.gz

3、配置Keepalived

cd keepalived-1.3.8/

./configure

此步骤可能出现错误&＃xff0c;

checking libnfnetlink/libnfnetlink.h usability... no

checking libnfnetlink/libnfnetlink.h presence... no

checking for libnfnetlink/libnfnetlink.h... no

configure: error: libnfnetlink headers missing

如下图&＃xff1a;

解决方法如下&＃xff1a;

将 usr.zip 包解压至keepalived-1.3.8目录&＃xff0c;解压&＃xff0c;然后执行

cp -R usr/ /

成功后&＃xff0c;重新执行

./configure

成功&＃xff0c;如下图&＃xff1a;

4、编译安装Keepalived

make

make install

3、配置防火墙

firewall-cmd --direct --permanent --add-rule ipv4 filter INPUT 0 / --in-interface p4p1 --destination 224.0.0.18 --protocol vrrp -j ACCEPT

firewall-cmd --direct --permanent --add-rule ipv4 filter OUTPUT 0 / --out-interface p4p1 --destination 224.0.0.18 --protocol vrrp -j ACCEPT

firewall-cmd --reload

注意&＃xff1a;上述【p4p1】为配置的网卡名称。

4、配置服务启动

cp /home/zz/user/software/keepalived-1.3.8/keepalived/etc/init.d/keepalived /etc/init.d/

mkdir /etc/keepalived

cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/

执行完成后&＃xff0c;即可使用服务的形式启动Keepalived&＃xff0c;如下&＃xff1a;

service keepalived start

如果使用 service keepalived status命令查看状态出现如下问题&＃xff1a;

/etc/init.d/keepalived:行15: /etc/sysconfig/keepalived: 没有那个文件或目录

则需要执行&＃xff1a;

ln -s /usr/local/etc/sysconfig/keepalived /etc/sysconfig/

执行成功后&＃xff0c;重启Keepalived服务&＃xff0c;即可查看状态。

如果Keepalived启动不成功&＃xff0c;错误信息如下&＃xff1a;

Keepalived_vrrp exited with permanent error CONFIG. Terminating

说明Keepalived 核心配置文件配置有误&＃xff0c;继续往下配置即可&＃xff0c;此问题先不用处理。

5、配置双机

Keepalived配置文件为&＃xff1a;/etc/keepalived/keepalived.conf&＃xff0c;

现进行如下配置&＃xff1a;

使用10.122.111.80 为主节点&＃xff0c;

使用10.122.111.81为从节点 进行配置&＃xff0c;

修改主节点80的配置文件 keepalived.conf&＃xff0c;内容修改如下所示&＃xff1a;! Configuration File for keepalived global_defs { notification_email { # acassen&＃64;firewall.loc # failover&＃64;firewall.loc # sysadmin&＃64;firewall.loc } notification_email_from Alexandre.Cassen&＃64;firewall.loc # smtp_server 192.168.200.1 # smtp_connect_timeout 30 router_id SERVER_1 vrrp_skip_check_adv_addr vrrp_garp_interval 0 vrrp_gna_interval 0 } vrrp_instance VI_1 { state MASTER interface p4p1 virtual_router_id 55 priority 100 protocol TCP advert_int 1 authentication {

auth_type PASS

auth_pass 1111 } virtual_ipaddress {

10.122.111.99/24 } }

修改从节点81的配置文件 keepalived.conf&＃xff0c;内容修改如下所示&＃xff1a;! Configuration File for keepalived global_defs { notification_email { # acassen&＃64;firewall.loc # failover&＃64;firewall.loc # sysadmin&＃64;firewall.loc } notification_email_from Alexandre.Cassen&＃64;firewall.loc # smtp_server 192.168.200.1 # smtp_connect_timeout 30 router_id SERVER_2 vrrp_skip_check_adv_addr vrrp_garp_interval 0 vrrp_gna_interval 0 } vrrp_instance VI_1 { state BACKUP interface p4p1 virtual_router_id 55 priority 50 protocol TCP advert_int 1 authentication {

auth_type PASS

auth_pass 1111 } virtual_ipaddress {

10.122.111.99/24 } }

配置完成后&＃xff0c;分别启动 Keepalived&＃xff0c;并进行状态查看&＃xff0c;如下图&＃xff1a;

6、配置非抢占模式

Keepalived默认为抢占模式&＃xff0c;主节点Master在故障回复重新开启使用时会掠夺当前从服务器的虚拟IP&＃xff0c;重新占据中心地位&＃xff0c;在一个去中心化的集群中&＃xff0c;可配置非抢占模式&＃xff0c;即正在处于服务状态的主机虚拟IP不会被抢走知道此台服务器出现问题。

只需要在原有Master配置文件中修改如下配置即可(Backup节点无需更改)&＃xff1a;

nopreempt

state BACKUP

调整后的配置文件如下&＃xff1a;! Configuration File for keepalived global_defs { notification_email { # acassen&＃64;firewall.loc # failover&＃64;firewall.loc # sysadmin&＃64;firewall.loc } notification_email_from Alexandre.Cassen&＃64;firewall.loc # smtp_server 192.168.200.1 # smtp_connect_timeout 30 router_id SERVER_1 vrrp_skip_check_adv_addr vrrp_garp_interval 0 vrrp_gna_interval 0 } vrrp_instance VI_1 { state BACKUP # 此处由MASTER调整为BACKUP nopreempt # 此处添加非抢占模式配置 interface p4p1 virtual_router_id 55 priority 100 protocol TCP advert_int 1 authentication {

auth_type PASS

auth_pass 1111 } virtual_ipaddress {

10.122.111.99/24 } }

7、查看虚拟IP指向

判断当前服务器是否拥有虚拟IP&＃xff0c;执行如下命令&＃xff0c;如果有结果则说明当前服务器正处于服务状态&＃xff0c;如果查询为空&＃xff0c;则说明当前服务器不用有虚拟IP&＃xff0c;处于备用状态。

ip addr|grep 10.122.111.99

说明当前服务器拥有虚拟IP。

8、如何判断脑裂&＃xff1f;