lvs+keepalived实现高可用负载均衡集群

时间 2019-11-15

标签 lvs+keepalived lvs keepalived 实现可用负载均衡集群栏目负载均衡繁體版

原文原文链接

1、LVS+Keepalived介绍

1. LVSlinux

‍LVS是Linux Virtual Server的简写，意即Linux虚拟服务器，是一个虚拟的服务器集群系统。本项目在1998年5月由章文嵩博士成立，是中国国内最先出现的自由软件项目之一。目前有三种IP负载均衡技术（VS/NAT、VS/TUN和VS/DR）；八种调度算法（rr,wrr,lc,wlc,lblc,lblcr,dh,sh）。‍算法

2. Keepalivedbash

Keepalived在这里主要用做RealServer的健康状态检查以及LoadBalance主机和BackUP主机之间failover的实现。服务器

2、网站负载均衡拓朴图

+---------------------------------VIP（192.168.1.222）---------------------------------+app

| | |负载均衡

| | |oop

server（MASTER）<--------------------keepalived------------------->server（BACKUP）网站

192.168.1.202 192.168.1.204spa

IP规划：操作系统

Hostname	IP
VIP	192.168.1.222
MASTER	192.168.1.202
BACKUP	192.168.1.204
REALSERVER1	192.168.1.203
REALSERVER2	192.168.1.201

3、部署步骤

安装LVS和Keepalived软件包

1. 下载相关软件包

mkdir /usr/local/src/lvs

cd /usr/local/src/lvs

wget http://down1.chinaunix.net/distfiles/ipvsadm-1.24.tar.gz

wget http://www.keepalived.org/software/keepalived-1.2.19.tar.gz

2. 安装LVS和Keepalived

lsmod |grep ip_vs #显示已载入系统的ip_vs模块

uname -r #显示操做系统的发行版号

2.6.32-279.el6.x86_64 #操做系统的发行版号

yum install kernel-devel #安装与系统内核配套的开发包

yum -y install popt*

yum -y install libnl*

yum -y install openssl*

ln -s /usr/src/kernels/2.6.32-279.9.1.el6.x86_64/ /usr/src/linux #创建软链接

tar zxvf ipvsadm-1.24.tar.gz

cd ipvsadm-1.24

make && make install

find / -name ipvsadm # 查看ipvsadm的位置

tar zxvf keepalived-1.1.15.tar.gz

cd keepalived-1.1.15

./configure && make && make install

find / -name keepalived # 查看keepalived位置

cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/

cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/

mkdir /etc/keepalived

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

cp /usr/local/sbin/keepalived /usr/sbin/

service keepalived start|stop #作成系统启动服务方便管理.

3. 配置realserver脚本

在192.168.203（realserver）上配置，脚本我保存在了/opt下

#!/bin/bash

#description Config LVS to realserver lo and apply noarp

#Written by ce

VIP=192.168.1.222

. /etc/init.d/functions

case "$1" in

start)

ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP

echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore

echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce

echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore

echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce

sysctl -p >/dev/null 2>&1

echo "RealServer Start OK"

;;

stop)

ifconfig lo:0 down

echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore

echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce

echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore

echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce

echo "RealServer Stoped"

;;

echo "Usage: $0 {start|stop}"

exit 1

esac

exit 0

chmod a+x /opt/realserver.sh #赋予可执行权限

/opt/realserver.sh start #启动

以后，经过rsync远程备份到192.168.1.201（另外一台realserver上）

rsync -av /opt/realserver.sh root@192.168.1.201:/root/

而后，在192.168.1.201上启动realserver脚本。

4. 利用keepalived实现负载均衡和高可用性

1. 配置在主负载均衡服务器(192.168.1.202)上配置keepalived.conf

vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {

router_id LVS_DEVEL

}

vrrp_instance VI_1 {

state MASTER

interface eth0

virtual_router_id 51

priority 100

advert_int 1

authentication {

auth_type PASS

auth_pass 1111

}

virtual_ipaddress {

192.168.1.222

}

virtual_server 192.168.1.222 80 {

delay_loop 6

lb_algo wrr

lb_kind DR

persistence_timeout 60

protocol TCP

real_server 192.168.1.203 80 {

weight 3

TCP_CHECK {

connect_timeout 10

nb_get_retry 3

delay_before_retry 3

connect_port 80

}

real_server 192.168.1.201 80 {

weight 3

TCP_CHECK {

connect_timeout 10

nb_get_retry 3

delay_before_retry 3

connect_port 80

}

2. 配置在备份负载均衡服务器(192.168.1.204)上配置keepalived.conf

vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {

router_id LVS_DEVEL

}

vrrp_instance VI_1 {

state BACKUP

interface eth0

virtual_router_id 51

priority 99

advert_int 1

authentication {

auth_type PASS

auth_pass 1111

}

virtual_ipaddress {

192.168.1.222

}

virtual_server 192.168.1.222 80 {

delay_loop 6

lb_algo wrr

lb_kind DR

persistence_timeout 60

protocol TCP

real_server 192.168.1.203 80 {

weight 3

TCP_CHECK {

connect_timeout 10

nb_get_retry 3

delay_before_retry 3

connect_port 80

}

real_server 192.168.1.201 80 {

weight 3

TCP_CHECK {

connect_timeout 10

nb_get_retry 3

delay_before_retry 3

connect_port 80

}

3. 启动keepalived

/etc/init.d/keepalived start（或者service keepalived start）

启动keepalived 服务，keepalived就能利用keepalived.conf 配置文件，实现负载均衡和高可用. 整个LVS负均衡HA方案，由keepalived.conf一个文件便可搞定！‍

4. 查看lvs服务是否正常

ipvsadm -ln

IP Virtual Server version 1.2.1 (size=4096)

Prot LocalAddress:Port Scheduler Flags

-> RemoteAddress:Port Forward Weight ActiveConn InActConn

TCP 192.168.1.200:80 wrr persistent 60

-> 192.168.1.203:80 Route 3 0
-> 192.168.1.201:80 Route 3 0

tail ‍‍–f /var/log/message‍‍ 监听日志，查看状态。