commit 8a0faeaf4a552739aa88847ecc1c0d5b325eefb8 Author: xiaoshun Date: Sun Jun 9 16:49:44 2024 +0800 上传文件至 / diff --git a/keepalived高可用集群.md b/keepalived高可用集群.md new file mode 100644 index 0000000..64b85ea --- /dev/null +++ b/keepalived高可用集群.md @@ -0,0 +1,366 @@ +# keepalived高可用集群 + +### keepalived介绍 + + keepalived是集群管理中保证集群高可用的一个服务软件，其功能类似于heartbeat，用来防止单点故障。 + +**脑裂**问题： + +backup vip + +master vip + +解决：**stonith** `shoot the other node in the head` **爆头** + +重启keepalived 关闭keepalived服务 + +### keepalived工作原理 + + keepalived是以**VRRP**协议为实现基础的，是实现路由器高可用的协议，VRRP全称Virtual Router Redundancy Protocol，即**虚拟路由冗余协议。** + +面试题(keepalived的工作原理) +**将N台提供相同功能的服务器组成一个服务器组，这个组里面有一个master和多个backup，master上面有一个对外提供服务的vip（该服务器所在局域网内其他机器的默认路由为该vip），master会发组播，当backup收不到vrrp包时就认为master宕掉了，这时就需要根据VRRP的优先级来选举一个backup当master** + +keepalived主要有三个模块，分别是**core、check和vrrp**。core模块为keepalived的核心，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，包括常见的各种检查方式。vrrp模块是来实现VRRP协议的。 + +### keepalived部署 + + ++++++++++++ + + +---------------------------> + Client + 192.168.122.1/24 (真实机做客户端) + | ++++++++++++ + | ________________|________________ VIP eth0:1 192.168.122.254/24 + | | | + | ++++++++++++++++ +++++++++++++++++ + | + Director master + + Director backup + + | ++++++++++++++++ +++++++++++++++++ + | DIP eth0 192.168.122.10/24 DIP eth0 192.168.122.20/24 + | |____________________________________________________________| + |___________________________________________________________________ ____________________ _________|__________________________________________________ + | | + | | + + ++++++++++++++++ ++++++++++++++++ + + \+ Real Server A + + Real Server B + + + ++++++++++++++++ ++++++++++++++++ + + eth0 192.168.122.30/24 eth0 192.168.122.40/24 + +**分别在Director master、Director backup 上部署浮动资源（VIP IPVS策略）** +**测试2个Director在DR模式下都工作正常。测试完成后都撤掉浮动资源。** + +**web上操作** + +web01 web02 添加同一网段虚拟网卡 且都是同一网段的 + +**lvs上操作** + +在两台dr配置keepalivied (lvs上) + +**1. 在master上安装配置Keepalived** + +```bash +# yum install keepalived -y +``` + +**2. 修改配置文件**(清空原有配置文件) + +```bash +# cd /etc/keepalived/ +# vim keepalived.conf +``` + +//全局配置 +! 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 Director1** //两边是一样的 + } +//局部配置 +vrrp_instance VI_1 { + state **MASTER** //另外一台机器是BACKUP + interface **eth0** //心跳网卡 DIP那一块网卡 + virtual_router_id 51 + priority **50** //优先级 + advert_int 1 //检查间隔，单位秒 + authentication { + auth_type PASS + auth_pass 1111 + } + virtual_ipaddress { + **192.168.122.254/24 dev eth0** //VIP随便自己定义(和web的是一个虚拟IP) 只要是同一个网段就可以 + } + } + +virtual_server **192.168.122.254** 80 { //LVS 配置，VIP(和web的一个ip)上面是啥这块就是 ^ + delay_loop 3 //服务论询的时间间隔 + lb_algo rr //LVS 调度算法 + lb_kind DR // LVS 集群模式 + protocol TCP + real_server **192.168.122.30** 80 { + weight 1 + TCP_CHECK { + connect_timeout 3 + } + } + real_server **192.168.122.40** 80 { + weight 1 + TCP_CHECK { + connect_timeout 3 + } + } +} + +**3.在backup上安装keepalived** + +```bash +# yum install keepalived -y +``` + +**4.拷贝master上的keepalived.conf到backup上：** + +```bash +# scp keepalived.conf 192.168.122.20:/etc/keepalived/ +``` + +**5.拷贝后,修改配置文件** + state **BACKUP** + priority **100** + +**6.两个Director上启动服务** + +```bash +# systemctl start keepalived +``` + +**7.测试** +**7.测试** +1）观察lvs路由条目 +2）观察vip地址在哪台机器上（有可能两台机器上都有，但是他好用没有问题即可） +3）客户端浏览器访问vip +4）关闭master上的keepalived服务，再次访问vip + +### 扩展实验-keepalived+mysql + + mysql可以是以下3种情况 + +1、双主 + +2、mysql-cluster + +3、gelara集群 + +**项目环境** +VIP 192.168.122.100 +mysql1 192.168.122.10 +mysql2 192.168.122.20 + vip +主(keepalived) 主(keepalived） + +**实现过程概要** + +一、mysql 主主同步 +二、在两台mysql上安装keepalived +三、keepalived 主备配置文件 +四、mysql状态检测脚本/root/bin/keepalived_check_mysql.sh +五、测试及诊断 +注 keepalived之间使用vrrp组播方式通信使用的IP地址是224.0.0.18 +＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝ +**实施步骤** +**一、mysql 主主同步 <略>** + +**二、安装keepalived** + +```bash +两台 +# yum install keepalived -y +``` + +**三、keepalived 主备配置文件** +主备置文件不同处有 state priority + +------ + +**192.168.122.10 Master配置** + +```bash +# vim /etc/keepalived/keepalived.conf +``` + +! Configuration File for keepalived + +global_defs { + router_id mysql1 //两边一样 +} + +**vrrp_script** **check_run** { //定义配置健康检查脚本的配置名称**check_run** + script "/root/keepalived_check_mysql.sh" + interval **5** //执行健康检查的时间间隔 单位s +} + +vrrp_instance VI_1 { + state MASTER + interface eth0 + virtual_router_id 88 + priority 100 + advert_int 1 //检查keepalived本身服务的时间间隔 + authentication { + auth_type PASS + auth_pass 1111 + } + + track_script { + **check_run** //名字必须和上面的脚本配置名称一致 + } + + virtual_ipaddress { + **192.168.122.100** dev **eth0** + } +} + +------ + +**192.168.122.20 Slave配置** + +```bash +# vim /etc/keepalived/keepalived.conf +``` + +! Configuration File for keepalived + +global_defs { + router_id mysql1 +} + +vrrp_script check_run { + script "/root/keepalived_check_mysql.sh" + interval 5 +} + +vrrp_instance VI_1 { + state **BACKUP** + interface eth0 + virtual_router_id 88 + priority **90** + advert_int 1 + authentication { + auth_type PASS + auth_pass 1111 + } + + track_script { + check_run + } + + virtual_ipaddress { + **192.168.122.100** + } +} + +**四、mysql状态检测脚本** + +/root/keepalived_check_mysql.sh（两台MySQL同样的脚本） + +版本一：简单使用： +#!/bin/bash +/usr/bin/mysql -h ip -uroot -p123 -e "show status;" &>/dev/null +if [ $? -ne 0 ] ;then + systemctl stop keepalived +fi + +#此处的ip是本地ip + +版本二：检查多次 + +vim /root/keepalived_check_mysql.sh + +#!/bin/bash +MYSQL=/usr/local/mysql/bin/mysql +MYSQL_HOST=localhost +MYSQL_USER=root +MYSQL_PASSWORD=1111 +CHECK_TIME=3 + +#mysql is working MYSQL_OK is 1 , mysql down MYSQL_OK is 0 +MYSQL_OK=1 + +check_mysql_helth (){ + $MYSQL -h $MYSQL_HOST -u $MYSQL_USER -p${MYSQL_PASSWORD} -e "show status;" &>/dev/null + if [ $? -eq 0 ] ;then + MYSQL_OK=1 + else + MYSQL_OK=0 + fi + return $MYSQL_OK +} + +while [ $CHECK_TIME -ne 0 ] +do + check_mysql_helth + if [ $MYSQL_OK -eq 1 ] ; then + exit 0 + fi + + if [ $MYSQL_OK -eq 0 ] && [ $CHECK_TIME -eq 1 ];then + /etc/init.d/keepalived stop + exit 1 + fi + let CHECK_TIME-- + sleep 1 +done + +版本三：检查多次 + +vim /root/keepalived_check_mysql.sh + +#!/bin/bash +MYSQL=/usr/local/mysql/bin/mysql +MYSQL_HOST=localhost +MYSQL_USER=root +MYSQL_PASSWORD=1111 +CHECK_TIME=3 + +#mysql is working MYSQL_OK is 1 , mysql down MYSQL_OK is 0 +MYSQL_OK=1 + +check_mysql_helth (){ + $MYSQL -h $MYSQL_HOST -u $MYSQL_USER -p${MYSQL_PASSWORD} -e "show status;" &>/dev/null + if [ $? -eq 0 ] ;then + MYSQL_OK=1 + else + MYSQL_OK=0 + fi + return $MYSQL_OK +} + +while [ $CHECK_TIME -ne 0 ] +do + check_mysql_helth + if [ $MYSQL_OK -eq 1 ] ; then + exit 0 + fi + + let CHECK_TIME-- + sleep 1 +done +/etc/init.d/keepalived stop +exit 1 + +chmod 755 /root/keepalived_check_mysql.sh + +两边均启动keepalived + +日志查看脚本是否被执行 + +tail -f /var/log/messages + +Jun 19 15:20:19 xen1 Keepalived_vrrp[6341]: Using LinkWatch kernel netlink reflector... +Jun 19 15:20:19 xen1 Keepalived_vrrp[6341]: VRRP sockpool: [ifindex(2), proto(112), fd(11,12)] +Jun 19 15:20:19 xen1 Keepalived_vrrp[6341]: VRRP_Script(check_run) succeeded \ No newline at end of file