LVS keepalived負載均衡實戰

lvs+keepalived負載均衡實戰

一、為什麼要使用負載均衡技術？

1、系統高可用性

2、系統可擴充套件性

3、負載均衡能力

lvs+keepalived能很好的實現以上的要求，lvs提供負載均衡，keepalived提供健康檢查，故障轉移，提高系統的可用性！採用這樣的架構以後很容易對現有系統進行擴充套件，只要在後端新增或者減少realserver，只要更改lvs的配置檔案，並能實現無縫配置變更！

二、lvs+keepalived介紹

1、 lvs

lvs是乙個開源的軟體，可以實現linux平台下的簡單負載均衡。lvs是linux virtual server的縮寫，意思是linux虛擬伺服器。目前有三種ip負載均衡技術（vs/nat、vs/tun和vs/dr）；八種排程演算法（rr,wrr,lc,wlc,lblc,lblcr,dh,sh）。

2、 keepalived

keepalived 是執行在lvs 之上，它的主要功能是實現真實機的故障隔離及負載均衡器間的失敗切換，提高系統的可用性

三、lvs+keepalived負載均衡架構圖

四、lvs+keepalived的安裝和配置

1. 配置環境

system os：centos release 5.4

software：ipvsadm-1.24.tar.gz, keepalived-1.1.19.tar.gz

2. 資訊列表

名稱ip

lvs-master

192.168.1.112

lvs-backup

192.168.1.113

lvs-vip

192.168.1.115

realserver1

192.168.1.105

realserver2

192.168.1.103

realserver3

192.168.1.104

3. 安裝lvs

分別在backup lvs和master lvs上安裝

wget

ln -s /usr/src/kernels/2.6.18-164.el5-i686/ /usr/src/linux

tar zxvf ipvsadm-1.24.tar.gz

cd ipvsadm-1.24

make && make install

4. 安裝keepalived

分別在backup lvs和master lvs上安裝

wget

tar zxvf keepalived-1.1.19.tar.gz

cd keepalived-1.1.19

./configure --prefix=/usr/local/keepalived

make

make install

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

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

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

mkdir /etc/keepalived

5. 配置keepadlived

lvs-master的配置檔案如下

# cat /etc/keepalived/keepalived.conf

global_defs

notification_email_from [email protected]

smtp_server 127.0.0.1

smtp_connect_timeout 30

router_id lvs1 # 設定lvs的id，在乙個網路內應該是唯一的

}vrrp_sync_group test

}vrrp_instance loadbalance

virtual_ipaddress

}virtual_server 192.168.1.115 80

}real_server 192.168.1.103 80

}real_server 192.168.1.104 80 }}

lvs-backup的配置檔案如下

global_defs

notification_email_from [email protected]

smtp_server 127.0.0.1

smtp_connect_timeout 30

router_id lvs2

}vrrp_sync_group test

}vrrp_instance loadbalance

virtual_ipaddress

}virtual_server 192.168.1.115 80

}real_server 192.168.1.103 80

}real_server 192.168.1.104 80 }}

6. realserver的配置

三颱客戶端的指令碼都一樣！

cat /etc/rc.d/init.d/realserver.sh

#!/bin/bash

sns_vip=192.168.1.115

/etc/rc.d/init.d/functions

case "$1" in

start)

ifconfig lo:0 $sns_vip netmask 255.255.255.255 broadcast $sns_vip

/sbin/route add -host $sns_vip dev lo:0

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

route del $sns_vip >/dev/null 2>&1

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 "

exit 1

esac

exit 0

7. 測試

1) 首先測試各個readserver，確定各個readserver都能正常訪問，測試realserver.sh指令碼，看啟動後能不能繫結lvs vip，停止後能不能去除繫結的vip

2) 測試lvs能否進行負載均衡**，利用ipvsadm命令檢視，如果想只當當前的請求**到哪個伺服器去了，可以用ipvsadm加選項來檢視，其完整形式為：ipvsadm –lcn | grep 192.168.1.115

3) 停掉主lvs看lvs backup是否接管！

4) 更詳細資訊請檢視日誌，tail -f /var/log/messages

LVS keepalived負載均衡實戰

LVS Keepalived負載均衡配置

LVS keepalived負載均衡 DR

LVS Keepalived構建高可用負載均衡

LVS keepalived負載均衡實戰

LVS Keepalived負載均衡配置

LVS keepalived負載均衡 DR

LVS Keepalived構建高可用負載均衡

相關推薦