lvs是一种负载均衡技术.注意区分负载均衡和高可用的区别.

 

keepalive是lvs的管理工具

ipvsadm也是lvs的管理工具

keepalive借助ipvsadm管理lvs.所以通常说lvs+keepalive

 

lvs支持多种负载方式.

理论及配置说明:

 

lvs:DR模式wrr负载:

拓扑

　　　　KA1    LAMP-1

pc------|

　　　　KA2　 LAMP-2

VIP:192.168.14.100

KA1:192.168.14.134

KA1:192.168.14.135

LAMP-1:192.168.141

LAMP-2:192.168.142

 

安装软件:

lvs:

yum install ipvsadm -y rpm -qa ipvsadm

KA:

yum install keepalived -y

 

lamp:配置

RS绑定VIP：ip addr add 192.168.14.100/32 dev lo label lo:1route add -host 192.168.14.100 dev lo抑制ARP：echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignoreecho "2" >/proc/sys/net/ipv4/conf/lo/arp_announceecho "1" >/proc/sys/net/ipv4/conf/all/arp_ignoreecho "2" >/proc/sys/net/ipv4/conf/all/arp_announce

 

前期准备:

KA的配置文件:主KA

/etc/keepalived/keepalived.conf

! Configuration File for keepalivedglobal_defs {   router_id LVS_19   vrrp_mcast_group4 224.0.1.18}vrrp_instance VI_1 {    state MASTER    interface eth0    virtual_router_id 199    priority 150    advert_int 1    authentication {        auth_type PASS        auth_pass 1098    }    virtual_ipaddress {      192.168.14.100/24 dev eth0 label eth0:1    }}#ipvsadm -A -t 192.168.14.100:80 -s rr -p 300virtual_server 192.168.14.100 80 {    delay_loop 6                  lb_algo wrr                    lb_kind DR                    nat_mask 255.255.255.0    persistence_timeout 50         protocol TCP               #ipvsadm -a -t 192.168.14.100:80 -r 10.0.1.6:80 -g     real_server 192.168.14.141 80 {        weight 1                      TCP_CHECK {        connect_timeout 8               nb_get_retry 3        delay_before_retry 3        connect_port 80        }    }    real_server 192.168.14.142 80 {        weight 1                      TCP_CHECK {        connect_timeout 8               nb_get_retry 3        delay_before_retry 3        connect_port 80        }    }}

备:KA:

! Configuration File for keepalivedglobal_defs {   router_id LVS_19   vrrp_mcast_group4 224.0.1.18}vrrp_instance VI_1 {    state BACKUP    interface eth0    virtual_router_id 199    priority 100    advert_int 1    authentication {        auth_type PASS        auth_pass 1098    }    virtual_ipaddress {      192.168.14.100/24 dev eth0 label eth0:1    }}#ipvsadm -A -t 192.168.14.100:80 -s rr -p 300virtual_server 192.168.14.100 80 {    delay_loop 6                  lb_algo wrr                    lb_kind DR                    nat_mask 255.255.255.0    persistence_timeout 50         protocol TCP               #ipvsadm -a -t 192.168.14.100:80 -r 10.0.1.6:80 -g     real_server 192.168.14.141 80 {        weight 1                      TCP_CHECK {        connect_timeout 8               nb_get_retry 3        delay_before_retry 3        connect_port 80        }    }    real_server 192.168.14.142 80 {        weight 1                      TCP_CHECK {        connect_timeout 8               nb_get_retry 3        delay_before_retry 3        connect_port 80        }    }}

检查:如果一台down了,另一台通过ifconfig就会出现绑定的VIP了

ip add |egrep  "134|135"

 

理论笔记:

集群--一组服务器

lvs harproxy nginx,keepalive heartbeat

负载均衡 高可用

负载模型:

nginx 7层负载

lvs 4层负载

lvs---nginx---webserver

负载:

1,7*24h服务

2,一台机器扛不住

lvs底层原理底层原理:

ipvs

ipvsadm自带

keepalive

名词介绍:

CIP(Client ip address)

DIP(Director IP address)

VIP(virtual ip address)

RIP(Real Server Ip address)=RS

负载的3种模式:

NAT

DR(direct route)

TUN(ip tunnel)

fullnat

DR

RIP

1,绑定VIP

2,抑制arp回应

主要:

LB通过修改目的mac,因此无法改写端口

2000W pv

请求10000一下都可以用haproxy/nginx

NAT模式:

LB要打开转发:

net.ipv4_forward=1