Practice makes perfect --HAProxy achieve web load balancing cluster (including source package can now do)

Practice makes perfect --HAProxy achieve web load balancing cluster (can do now)

Foreword

This paper describes the load balancing provided by nginx web site cluster-practice processes through Haproxy software.

Haproxy Brief

haproxy based on open source software written in C language, mainly to provide high availability, load balancing and other functions, to achieve its agents based on four or seven agreements.

The previously mentioned LVS load balancing is inadequate in that it does not support regular expressions and dynamic separation can not be achieved, and the more complex configuration for large sites.

haproxy support for common algorithms round robin, least connections, hash algorithm based on the source of access, etc.

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lab environment

A haproxy servers, two nginx server, a client

Address planning as follows:

name of server	IP address (NAT)
haproxy	20.0.0.128
Nx1	20.0.0.130
nginx2	20.0.0.131

The client is in the same segment.

Package:

Links: https://pan.baidu.com/s/1OWiwXR8hxys5EMilgBsD3A
extraction code: v53w

Lab topology

experiment process

1. Set up the configuration server haproxy

1) packages and environment configuration

[root@lokott ~]# hostnamectl set-hostname haproxy
[root@lokott ~]# su
[root@haproxy ~]# yum install bzip2-devel pcre-devel gcc gcc-c++ make -y
[root@haproxy ~]# tar zxvf haproxy-1.5.19.tar.gz -C /opt
[root@haproxy ~]# cd /opt
[root@haproxy opt]# ls
haproxy-1.5.19  rh

2) compile and install haproxy

#切换至haproxy目录
[root@haproxy opt]# cd haproxy-1.5.19/

#查看系统版本号3100
[root@haproxy haproxy-1.5.19]# uname -a
Linux haproxy 3.10.0-693.el7.x86_64 #1 SMP Tue Aug 22 21:09:27 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

#编译haproxy
[root@haproxy haproxy-1.5.19]# make TARGET=linux3100

#编译安装
[root@haproxy haproxy-1.5.19]# make install
#创建haproxy文件目录
[root@haproxy haproxy-1.5.19]# mkdir /etc/haproxy

#复制模板文件到haproxy目录
[root@haproxy haproxy-1.5.19]# cp examples/haproxy.cfg /etc/haproxy/

#修改haproxy.cfg文件
[root@haproxy haproxy-1.5.19]# vim /etc/haproxy/haproxy.cfg
#注释chroot和redispatch条目,防止启动失败
global
        log 127.0.0.1   local0
        log 127.0.0.1   local1 notice
        #log loghost    local0 info
        maxconn 4096
        #chroot /usr/share/haproxy
        uid 99
        gid 99
        daemon
        #debug
        #quiet

defaults
        log     global
        mode    http
        option  httplog
        option  dontlognull
        retries 3       
        #redispatch
        maxconn 2000
        contimeout      5000
        clitimeout      50000
        srvtimeout      50000

#删除原有的所有listen条目,添加一下条目
listen webcluster 0.0.0.0:80
       option httpchk GET /index.html
       balance roundrobin
       server inst1 20.0.0.130:80 check inter 2000 fall 3
       server inst2 20.0.0.131:80 check inter 2000 fall 3

#复制haproxy启动脚本到系统启动进程中

3) optimization

#复制haproxy启动脚本到系统启动进程中
[root@haproxy haproxy-1.5.19]# cp examples/haproxy.init /etc/init.d/haproxy

#授予脚本执行权限
[root@haproxy haproxy-1.5.19]# chmod +x /etc/init.d/haproxy

#添加脚本到service管理条目中
[root@haproxy haproxy-1.5.19]# chkconfig --add haproxy 

#建立脚本命令软链接
[root@haproxy haproxy-1.5.19]# ln -s /usr/local/sbin/haproxy /usr/sbin/haproxy

#启动服务
[root@haproxy haproxy-1.5.19]# service haproxy start
Starting haproxy (via systemctl):                          [  确定  ]

#关闭防火墙和安全功能
[root@Haproxy haproxy-1.5.19]# systemctl stop firewalld.service 
[root@Haproxy haproxy-1.5.19]# setenforce 0

2, two servers manually compile and install nginx

Previous article nginx manually compile and install process has been described in detail, this paper gives direct installation configuration process, but many go, mainly in the final verification page content load balancing two needs are not the same (experiments), where patients with nginx1

[root@nginx1 ~]# yum install zlib-devel pcre-devel gcc gcc-c++ make -y
#解压Nginx源码包到/opt目录
root@nginx1 ~]# tar zxvf nginx-1.12.0.tar.gz -C /opt

#创建Nginx管理用户
root@nginx1 ~]# cd /opt
[root@nginx1 opt]# useradd -M -s /sbin/nologin nginx

[root@nginx1 opt]# cd nginx-1.12.0/
[root@nginx1 nginx-1.12.0]# ./configure --prefix=/usr/local/nginx --user=nginx --group=nginx
.编译安装

[root@nginx1 nginx-1.12.0]# make && make install

[root@nginx1 nginx-1.12.0]# cd /usr/local/nginx/html/
[root@nginx1 html]# echo "this is nginx1 web" >index.html

[root@nginx2 nginx-1.12.0]# cd /usr/local/nginx/html/
[root@nginx2 html]# echo "this is nginx2 web" >index.html

[root@nginx1 html]# ln -s /usr/local/nginx/sbin/nginx  /usr/local/sbin/

[root@nginx1 html]# systemctl stop firewalld.service 
[root@nginx1 html]# setenforce 0
[root@nginx1 html]# nginx

3, testing and certification

As shown below:

Brief profile parameters haproxy

Haproxy configuration file is usually divided into three portions

global: Configure global
defaults: the default configuration
configured application components: listen

1、global配置参数

log127.0.0.1 lcal0：配置日志记录，local0为日志设备，默认存放到系统日志
log127.0.0.1 loca1 notice:notice为日志级别，通常有24个级别
maxconn4096：最大连接数
uid 99：用户uid
gid 99：用户gid

2、defaults配置项配置默认参数，一般会被应用组件继承，如果在应用组件中没有特别声明，将安装默认配置参数设置

log global：定义日志为global配置中的日志定义
mode http：模式为http
option httplog：采用http日志格式记录日志
retries 3：检查节点服务器失败连续达到三次则认为节点不可用
maxconn2000：最大连接数（可以优化）
contimeout5000：连接超时时间
clitimeout50000：客户端超时时间
srvtimeout50000：服务器超时时间

3、listen配置项目一般为配置应用模块参数

listen appli4- backup 0.0.0.0:10004：定义一个appli4- backup的应用
option httpchk /index.html检查服务器的index.html文件
option persist：强制将请求发送到已经down掉的服务器
balance roundrobin：负载均衡调度算法使用轮询算法
server inst1 20.0.0.130:80 check inter 2000 fall 3：定义在线节点
server inst2 20.0.0.131:81 check inter 2000 fall 3 backup：定义备份节点