用HAProxy和KeepAlived构建高可用的反向代理

时间：2024-01-19 21:31:44
用HAProxy和KeepAlived构建高可用的反向代理

用HAProxy和KeepAlived构建高可用的反向代理 前言对于访问量较大的网站来说，随着流量的增加单台服务器已经无法处理所有的请求，这时候需要多台服务器对大量的请求进行分流处理，即负载均衡。而如果实 现负载均衡，必须在网站的入口部署服务器（不只是一台）对这些请求进行分发，这台服务器即反向代理。由于反向代理服务器是网站的入口，其负载压力大且易遭 到攻击，存在单点故障的风险，所以我们需要一个高可用的方案来实现当一台反向代理服务器宕机的时候，另一台服务器会自动接管服务。基于以上要求，我们使用 HAProxy，KeepAlived来构建高可用的反向代理系统。 介绍HAProxy是高性能的代理服务器，其可以提供7层和4层代理，具有healthcheck，负载均衡等多种特性，性能卓越，国内很多大的互联网公 司都在使用， KeepAlived是一个高可用方案，通过VIP(即虚拟IP)和心跳检测来实现高可用。其原理是存在一组（两台）服务器，分别赋予 Master,Backup两个角色，默认情况下Master会绑定VIP到自己的网卡上，对外提供服务。Master,Backup会在一定的时间间隔 向对方发送心跳数据包来检测对方的状态，这个时间间隔一般为2秒钟，如果Backup发现Master宕机，那么Backup会发送ARP包到网关，把 VIP绑定到自己的网卡，此时Backup对外提供服务，实现自动化的故障转移，当Master恢复的时候会重新接管服务。

部署环境准备

环境OS: CentOS Linux release 6.0 (Final) 2.6.32-71.29.1.el6.x86_64

HAProxy: 1.5.10

KeepAlived: 1.2.2

VIP: 192.168.36.100

M: 192.168.36.154

S: 192.168.36.129

架构

                   192.168.36.100

             +-----------VIP----------+

             |                        |

             |                        |

           Master                   Backup

        192.168.36.129            192.168.36.154

        +----------+             +----------+

        | HAProxy  |             | HAProxy  |

        |keepalived|             |keepalived|

        +----------+             +----------+

             |

             v

    +--------+---------+

    |        |         |

    |        |         |

    v        v         v

+------+  +------+  +------+

| WEB1 |  | WEB2 |  | WEB3 |

+------+  +------+  +------+

安装HAProxy

安装pcre

 yum install pcre

 wget wget http://www.haproxy.org/download/1.5/src/haproxy-1.5.10.tar.gz

 tar -zxvf haproxy-1.5.10.tar.gz

 cd haproxy-1.5.10

注意编译参数：

TARGET是指自己系统的内核版本 ARCH指定系统是32位还是64位

CPU=native: use the build machine's specific processor optimizations

更多编译参数内容见源码中的README

 make TARGET=linux26 make TARGET=linux26 USE_OPENSSL=1 ADDLIB=-lz  #编译支持ssl认证功能，haproxy 1.5t版本以上才支持。

 make install

 ln -s /usr/local/src/haproxy-1.5.10 /usr/local/haproxy

 mkdir /usr/local/haproxy/etc

配置文件hparoxy

cd haproxy-1.5.10

cat etc/haproxy.cfg

global

    log 127.0.0.1   local3 info

    maxconn 20000

    user lashourun

    group lashourun

    chroot /var/chroot/haproxy

    daemon

    nbproc 4

defaults

   log     127.0.0.1       local3

   mode    http

   option  httplog

   option  httpclose

   option  dontlognull

   option  forwardfor

   option accept-invalid-http-request

   retries 2

   balance roundrobin

   stats enable

   stats   uri   /admin

   stats  auth haadmin:lashoupay

   timeout http-request 20s

   timeout connect 50000

   timeout client 500000

   timeout server 500000

frontend lashoupay-http #支持http 80端口访问的业务

    bind *:80

    reqadd X-Forwarded-Proto:\ http

    #acl lashoupay-4.90 dst 192.168.4.90

    acl lashoupay-4.90 path_beg /lashoupay/lashoupay || dst 192.168.4.90

    acl vs-lashoupay-index-4.94 dst 192.168.4.111

    #acl vs-lsmvas-4.51 dst 192.168.4.51

    #acl vs-lsmvas-4.93 dst 192.168.4.93

    acl vs-pay-4.90 dst  192.168.4.114

    acl vs-project-4.95 dst 192.168.4.115

    use_backend lashoupay-4.90-pool if lashoupay-4.90

    use_backend vs-lashoupay-index-4.94-pool if vs-lashoupay-index-4.94

    #use_backend vs-lsmvas-4.51-pool if vs-lsmvas-4.51

    #use_backend vs-lsmvas-4.93-pool if vs-lsmvas-4.93

    use_backend vs-pay-4.90-pool if vs-pay-4.90

    use_backend vs-project-4.95-pool if vs-project-4.95

frontend lashoupay-https #支持https 443 ssl认证访问的业务

    bind *:443 ssl crt /usr/local/haproxy/cert.pem

    option httpclose

    option forwardfor

    reqadd X-Forwarded-Proto:\ https

    default_backend lashoupay-4.90-pool

frontend vs-lsmvas4.51-9002  #支持一些特殊业务端口访问

    mode http

    bind *:9002

    reqadd X-Forwarded-Proto:\ http

    acl vs-lsmvas-4.51 dst 192.168.4.51

    acl vs-lsmvas-4.93 dst 192.168.4.93

    use_backend vs-lsmvas-4.51-pool if vs-lsmvas-4.51

    use_backend vs-lsmvas-4.93-pool if vs-lsmvas-4.93

backend lashoupay-4.90-pool

    redirect scheme https if !{ ssl_fc }

    balance roundrobin

        stats refresh 2

        server lashoupay-4.73 192.168.4.73:80 weight 3 maxconn 10000 check

backend vs-lashoupay-index-4.94-pool

    balance roundrobin

    stats refresh 2

    server lashoupay-index-16-26 192.168.4.16:9002 weight 3 maxconn 10000 check

backend vs-lsmvas-4.51-pool

    balance roundrobin

    stats refresh 2

    #server vs-lsmvas-4.16 192.168.4.16:9002 weight 3 maxconn 10000 check

    server vs-lsmvas-4.18 192.168.4.18:9002 weight 3 maxconn 10000 check

    server vs-lsmvas-4.26 192.168.4.26:9002 weight 3 maxconn 10000 check

    server vs-lsmvas-4.28 192.168.4.28:9002 weight 3 maxconn 10000 check

backend vs-lsmvas-4.93-pool

    balance roundrobin

    stats refresh 2

    server vs-lsmvas-4.18 192.168.4.18:9002 weight 3 maxconn 10000 check

    server vs-lsmvas-4.28 192.168.4.28:9002 weight 3 maxconn 10000 check

backend vs-pay-4.90-pool

    balance roundrobin

    stats refresh 2

    #server vs-lsmvas-4.16 192.168.4.16:9002 weight 3 maxconn 10000 check

    server vs-lsmvas-4.18 192.168.4.18:9002 weight 3 maxconn 10000 check

    server vs-lsmvas-4.26 192.168.4.26:9002 weight 3 maxconn 10000 check

    server vs-lsmvas-4.28 192.168.4.28:9002 weight 3 maxconn 10000 check

backend vs-project-4.95-pool

    balance roundrobin

    stats refresh 2

    server project-4.17 192.168.4.17:9002 weight 3 maxconn 10000 check

    server project-4.27 192.168.4.27:9002 weight 3 maxconn 10000 check

查看HAProxy的状态：http://192.168.36.100/haproxy-stats，这个页面会显示HAProxy本身以及后端服务器的状态。

日志haproxy会把日志记录发送到syslog server(CentOS6下是rsyslogd，UDP514端口)， 编辑/etc/rsyslog.conf文件，添加如下内容：

ModLoad imudp

UDPServerRun 514

UDPServerAddress 127.0.0.1

local3.*                /var/log/haproxy.log

重启rsyslog

 /etc/init.d/rsyslog restart

自动轮转日志，编辑/etc/logrotate.d/haproxy.cfg，添加如下内容：

/var/log/haproxy.log

{

    rotate 4

    daily

    missingok

    notifempty

    compress

    delaycompress

    sharedscripts

    postrotate

    reload rsyslog > /dev/null 2>&1 || true

    endscript

}

启动脚本

 wget -O haproxy https://raw.github.com/gist/3665034/4125bd5b81977a72e5eec30650fb21f3034782a0/haproxy-init.d

 cp haproxy /etc/init.d/haproxy

 chmod +x /etc/init.d/haproxy

#使用方式

 /etc/init.d/haproxy start|stop|restart

安装KeepAlived

安装依赖库

 yum install popt popt-devel

 wget http://www.keepalived.org/software/keepalived-1.2.2.tar.gz

 tar -zxvf keepalived-1.2.2.tar.gz

 cd keepalived-1.2.2

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

 make && make install

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

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

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

 mkdir -p /etc/keepalived/

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

 chmod +x /etc/init.d/keepalived

使用方式

 /etc/init.d/keepalived start|stop|restart

Master服务器上的配置

cat etc/keepalived/keepalived.conf

global_defs {

   notification_email {

       user@example.com

   }

   notification_email_from mail@example.org

   smtp_server 192.168.x.x

   smtp_connect_timeout 30

   router_id LVS_DEVEL

}

#监测haproxy进程状态，每2秒执行一次

vrrp_script chk_haproxy {

    script "/usr/local/keepalived/chk_haproxy.sh"

    interval 2

    weight 2

}

vrrp_instance VI_1 {

    state MASTER #标示状态为MASTER

    interface eth0

    virtual_router_id 51

    priority 101   #MASTER权重要高于BACKUP

    advert_int 1

    mcast_src_ip 192.168.36.129 #Master服务器IP

    authentication {

        auth_type PASS #主从服务器验证方式

        auth_pass 1111

    }

    track_script {

        chk_haproxy #监测haproxy进程状态

    }

    #VIP

    virtual_ipaddress {

        192.168.36.100 #虚拟IP

    }

}

Bakcup服务器上的配置

cat etc/keepalived/keepalived.conf

global_defs {

   notification_email {

   user@example.com

   }

   notification_email_from mail@example.org

   smtp_server 192.168.x.x

   smtp_connect_timeout 30

   router_id LVS_DEVEL

}

#监测haproxy进程状态，每2秒执行一次

vrrp_script chk_haproxy {

    script "/usr/local/keepalived/chk_haproxy.sh"

    interval 2

    weight 2

}

vrrp_instance VI_1 {

    state BACKUP #状态为BACKUP

    interface eth0

    virtual_router_id 51

    priority 100  #权重要低于MASTER

    advert_int 1

    mcast_src_ip 192.168.36.154 #Backup服务器的IP

    authentication {

        auth_type PASS

        auth_pass 1111

    }

    track_script {

        chk_haproxy #监测haproxy进程状态

    }

    #VIP

    virtual_ipaddress {

        192.168.36.100 #虚拟IP

    }

}
  • keepalived 配置中引用的脚本 chk_haproxy.sh内容
#!/bin/bash

#

# author: weizhifeng

# description:

# 定时查看haproxy是否存在，如果不存在则启动haproxy，

# 如果启动失败，则停止keepalived

#

status=(ps aux|grep haproxy | grep -v grep | grep -v bash | wc -l)

if [ "{status}" = "0" ]; then

    /etc/init.d/haproxy start

    status2=(ps aux|grep haproxy | grep -v grep | grep -v bash |wc -l)

    if [ "{status2}" = "0"  ]; then

            /etc/init.d/keepalived stop

    fi

fi

高可用测试

  • 1. 在Master上停止keepalived，查看系统日志，发IP
  /etc/init.d/keepalived stop

  tail -f /var/log/message

 Keepalived: Terminating on signal Keepalived: Stopping Keepalived v1.2.2 (11/03,2011)

 Keepalived_vrrp: Terminating VRRP child process on signal

 Keepalived_vrrp: VRRP_Instance(VI_1) removing protocol VIPs.
  • 2. 在Backup上查看系统日志，发现Backup已经进入MASTER角色，并且绑定了VIP 192.168.36.100
  tail -f /var/log/message

 Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE

 Keepalived_vrrp: VRRP_Instance(VI_1) setting protocol VIPs

 Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.36.100 #在Backup上查看VIP是否已经绑定
  • 3. 在Master上重新启动keepalived，查看系统日志，发现重新获得MASTER角色，并且绑定VIP 192.168.36.100
  /etc/init.d/keepalived start

  tail -f /var/log/message

 Keepalived_vrrp: VRRP_Instance(VI_1) Transition to MASTER STATE

 Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE

 Keepalived_vrrp: VRRP_Instance(VI_1) setting protocol VIPs.

 Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.36.100
  • 4. 在Backup上查看系统日志，发现其重新回到BACKUP角色，并且释放VIP
  tail -f /var/log/message

 Keepalived_vrrp: VRRP_Instance(VI_1) Received higher prio advert

 Keepalived_vrrp: VRRP_Instance(VI_1) Entering BACKUP STATE

 Keepalived_vrrp: VRRP_Instance(VI_1) removing protocol VIPs.
  • 并发测试我们使用webbench来对HAProxy进行并发测试
 yum install ctags

 wget http://home.tiscali.cz/~cz210552/distfiles/webbench-1.5.tar.gz

 tar -zxvf webbench-1.5.tar.gz

 cd webbench-1.5

 make

 mkdir -p /usr/local/man && make install

测试方法：

 webbench -c 100 -t 3000 http://192.168.36.100/index.html

haproxy维护

  • 1,haproxy做前端代理，出错类 -1/-1/-1/-1/0 400 187 - - PR-- 0/0/0/0/0 0/0 "

    google了一下全是英文的，大概意思说原因是因为客户端发来了无效的字符，处理不了罢，说白了，就是可能不支持客户发来的字符集，

    我们查了一下发来的字符串中文的，好像是gb2312的，google有牛人给出的解决办法如下：

    打开haproxy.cfg配置加上如下

    timeout http-request 20s

    option accept-invalid-http-request

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