目錄

Haproxy概述

haproxy算法：

Haproxy實(shí)現(xiàn)七層負(fù)載

①部署nginx-server測(cè)試頁(yè)面

②(主/備)部署負(fù)載均衡器

?③部署keepalived高可用

?④增加對(duì)haproxy健康檢查

⑤測(cè)試

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Haproxy概述

haproxy---主要是做負(fù)載均衡的7層，也可以做4層負(fù)載均衡
apache也可以做7層負(fù)載均衡，但是很麻煩。實(shí)際工作中沒有人用。
負(fù)載均衡是通過OSI協(xié)議對(duì)應(yīng)的
7層負(fù)載均衡：用的7層http協(xié)議，
4層負(fù)載均衡：用的是tcp協(xié)議加端口號(hào)做的負(fù)載均衡

haproxy算法：

1.roundrobin
基于權(quán)重進(jìn)行輪詢,在服務(wù)器的處理時(shí)間保持均勻分布時(shí),這是最平衡,最公平的算法.此算法是動(dòng)態(tài)的,這表示其權(quán)重可以在運(yùn)行時(shí)進(jìn)行調(diào)整.不過在設(shè)計(jì)上,每個(gè)后端服務(wù)器僅能最多接受4128個(gè)連接
2.static-rr
基于權(quán)重進(jìn)行輪詢,與roundrobin類似,但是為靜態(tài)方法,在運(yùn)行時(shí)調(diào)整其服務(wù)器權(quán)重不會(huì)生效.不過,其在后端服務(wù)器連接數(shù)上沒有限制
3.leastconn
新的連接請(qǐng)求被派發(fā)至具有最少連接數(shù)目的后端服務(wù)器.

Haproxy實(shí)現(xiàn)七層負(fù)載

keepalived+haproxy

192.168.134.165? master

192.168.134.166 slave

192.168.134.163? nginx-server

192.168.134.164 nginx-server

192.168.134.160? ?VIP（虛擬IP）

①部署nginx-server測(cè)試頁(yè)面

兩臺(tái)nginx都部署方便測(cè)試

[root@server03 ~]# yum -y install nginx
[root@server03 ~]# systemctl  start nginx
[root@server03 ~]# echo "webserver01..." > /usr/share/nginx/html/index.html [root@server04 ~]# yum -y install nginx
[root@server04 ~]# systemctl  start nginx
[root@server04 ~]# echo "webserver02..." > /usr/share/nginx/html/index.html

②(主/備)部署負(fù)載均衡器

[root@server01 ~]# yum -y install haproxy
[root@server01 ~]# vim /etc/haproxy/haproxy.cfg
globallog         127.0.0.1 local2 infopidfile     /var/run/haproxy.pidmaxconn     4000user        haproxygroup       haproxydaemonnbproc 1
defaultsmode                    httplog                     globalretries                 3option                  redispatchmaxconn                 4000contimeout              5000clitimeout              50000srvtimeout              50000
listen statsbind                        *:81stats                       enablestats uri                   /haproxystats auth                  aren:123
frontend  webmode                        httpbind                            *:80option                  httplogacl html url_reg  -i  \.html$use_backend httpservers if  htmldefault_backend    httpservers
backend httpserversbalance     roundrobinserver  http1 192.168.134.163:80 maxconn 2000 weight 1  check inter 1s rise 2 fall 2server  http2 192.168.134.164:80 maxconn 2000 weight 1  check inter 1s rise 2 fall 2[root@server01 ~]# systemctl  start haproxy

瀏覽器訪問haproxy監(jiān)控

master:

slave:

頁(yè)面主要參數(shù)解釋
Queue
Cur: current queued requests //當(dāng)前的隊(duì)列請(qǐng)求數(shù)量
Max：max queued requests ????//最大的隊(duì)列請(qǐng)求數(shù)量
Limit： ??????????//隊(duì)列限制數(shù)量

Errors
Req：request errors ????????????//錯(cuò)誤請(qǐng)求
Conn：connection errors ?????????//錯(cuò)誤的連接

Server列表：
Status:狀態(tài)，包括up(后端機(jī)活動(dòng))和down(后端機(jī)掛掉)兩種狀態(tài)
LastChk: ???持續(xù)檢查后端服務(wù)器的時(shí)間
Wght: (weight) : 權(quán)重

?③部署keepalived高可用

注意：master和slave的優(yōu)先級(jí)不一樣，但虛擬路由id(virtual_router_id)保持一致；并且slave配置?nopreempt（不搶占資源）

master：

[root@server01 ~]# yum -y install keepalived
[root@server01 ~]# vim /etc/keepalived/keepalived.conf 
! Configuration File for keepalivedglobal_defs {router_id director1
}
vrrp_instance VI_1 {state MASTERinterface ens33virtual_router_id 80priority 100advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.134.160/24}
}[root@server01 ~]# systemctl  start keepalived

slaver：

[root@localhost ~]# yum -y install keepalived
[root@localhost ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalivedglobal_defs {router_id directory2
}
vrrp_instance VI_1 {state BACKUPinterface ens33nopreemptvirtual_router_id 80priority 50advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.134.160/24}
}
[root@localhost ~]# systemctl  start keepalived

查看IP

?④增加對(duì)haproxy健康檢查

兩臺(tái)機(jī)器都做，讓Keepalived以一定時(shí)間間隔執(zhí)行一個(gè)外部腳本，腳本的功能是當(dāng)Haproxy失敗，則關(guān)閉本機(jī)的Keepalived。

[root@server01 ~]# vim /etc/keepalived/check.sh
#!/bin/bash /usr/bin/curl -I http://localhost &>/dev/null
if [ $? -ne 0 ];then
#       /etc/init.d/keepalived stopsystemctl stop keepalived
fi
[root@server01 ~]# chmod a+x /etc/keepalived/check.sh

在keepalived增加健康檢查配置vrrp_script check_haproxy并且用?track_script調(diào)用。

! Configuration File for keepalivedglobal_defs {router_id director1
}
vrrp_script check_haproxy {script "/etc/keepalived/check.sh"interval 5
}
vrrp_instance VI_1 {state MASTERinterface ens33virtual_router_id 80priority 100advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.134.160/24}track_script {check_haproxy}
}

重啟keepalived

[root@server01 ~]# systemctl  restart keepalived

⑤測(cè)試

關(guān)閉master的haproxy服務(wù)可以發(fā)現(xiàn)master的keepalived服務(wù)也關(guān)閉，此時(shí)master上的VIP轉(zhuǎn)移到slave上

• 關(guān)閉master的服務(wù)并查看VIP

• 查看slave的IP可以發(fā)現(xiàn)VIP跳轉(zhuǎn)至此。

• 在web界面查看服務(wù)是否正常

第一次刷新

第二次刷新