现有问题

  1. 现在我们的Haproxy服务存在单点问题，也就是Haproxy服务一旦挂掉，就会导致用户连接不到Beeline，Hue服务也会出现问题

  2. 使用Keepalived来实现Haproxy的高可用，就是在两台服务器上部署Haproxy服务，当一个Haproxy服务出现问题，就立即切换到另一台Haproxy服务

    安装Haproxy

  3. 我们需要找两台主机安装Haproxy，一般为util节点或者边缘节点，

    1. # 两台主机都需要安装Haproxy服务
    2. yum install -y haproxy

  4. 两台主机的Haproxy配置文件保持一致 ```shell vim /etc/haproxy/haproxy.cfg

——————————————————————————————————-

Example configuration for a possible web application. See the

full configuration options online.

#

http://haproxy.1wt.eu/download/1.4/doc/configuration.txt

#

——————————————————————————————————-

——————————————————————————————————-

Global settings

——————————————————————————————————-

global

# to have these messages end up in /var/log/haproxy.log you will
# need to:
#
# 1) configure syslog to accept network log events.  This is done
#    by adding the '-r' option to the SYSLOGD_OPTIONS in
#    /etc/sysconfig/syslog
#
# 2) configure local2 events to go to the /var/log/haproxy.log
#   file. A line like the following can be added to
#   /etc/sysconfig/syslog
#
#    local2.*                       /var/log/haproxy.log
#
log         127.0.0.1 local0 info

chroot      /var/lib/haproxy
pidfile     /var/run/haproxy.pid
maxconn     4000
user        haproxy
group       haproxy
daemon

# turn on stats unix socket
stats socket /var/lib/haproxy/stats

——————————————————————————————————-

common defaults that all the ‘listen’ and ‘backend’ sections will

use if not designated in their block

——————————————————————————————————-

defaults mode http log global option httplog option dontlognull option http-server-close option forwardfor except 127.0.0.0/8 option redispatch retries 3 timeout http-request 10s timeout queue 1m timeout connect 10s timeout client 60m timeout server 60m timeout http-keep-alive 600s timeout check 10s maxconn 3000

contimeout 5000

clitimeout 50000

srvtimeout 50000

listen status

listen admin_stats stats enable bind *:8080 mode http option httplog log global maxconn 10 stats refresh 30s stats uri /admin?stats stats realm haproxy stats auth admin:admin stats hide-version stats admin if TRUE

Hive Server2

listen hive_server bind 0.0.0.0:10001 mode tcp option tcplog balance source server hive_server_01 master:10000 check server hive_server_02 node2:10000 check


3. 启动Haproxy服务，并设置开机自启
```shell
systemctl start haproxy
systemctl enable haproxy

安装Keepalived

  1. 需要向网络管理员申请和Haproxy服务所在主机同网段的虚IP，我这里申请为192.168.160.180

  2. 并且在集群中所有主机的/etc/hosts中加入虚IP

image.png

  1. 两台主机都需要安装Keepalived

    yum install -y keepalived

  2. 修改配置文件，配置文件需要保持一致 ```shell vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs { router_id node2 #router_id可以自己定义，一般是主机的hostname，需要唯一 }

vrrp_script check_haproxy { script “/etc/keepalived/haproxy_check.sh” interval 5 weight -20 }

vrrp_instance HAProxy_HA { state BACKUP #在 haproxy-server 和 backup-haproxy 上均配置为 BACKUP interface ens160 virtual_router_id 51 #virtual_router_id 两台主机需要保持一致 priority 100 advert_int 2 nopreempt #不抢占模式，只在优先级高的机器上设置即可，优先级低的机器不设置

authentication {
    auth_type PASS
    auth_pass 1111
}
    unicast_src_ip 192.168.160.197    #填写本机的ip
    unicast_peer {
            192.168.160.131    # 填写另一台主机的ip
    }
track_script {
    check_haproxy
}

virtual_ipaddress {
    192.168.160.180 #HAProxy 的对外服务 IP，即 VIP
}

}


3. 配置检测脚本，两个主机都需要配置
```shell
vim /etc/keepalived/haproxy_check.sh

#!/bin/bash
A=`ps -C haproxy --no-header | wc -l`
if [ $A -eq 0 ];then
/etc/init.d/haproxy start
sleep 3
if [ `ps -C haproxy --no-header | wc -l ` -eq 0 ];then
/etc/init.d/keepalived stop
fi
fi

  1. 给检测脚本添加可执行权限

    chmod +x /etc/keepalived/haproxy_check.sh

  2. 两台主机都启动keepalived服务,并设置开机自启

    systemctl start keepalived
systemctl enable keepalived

  3. 查看一台主机发现虚IP以及成功绑定

image.png

测试Keepalived

  1. 测试使用虚IP是否可以访问Haproxy的状态页面

image.png

  1. 关闭虚IP所在主机的Haproxy服务，然后查看虚IP是否漂移到另一台主机 ```shell

    关闭虚IP所在主机的Haproxy服务

    systemctl stop haproxy

查看虚IP是否可以飘逸到另一台Haproxy主机

![image.png](https://cdn.nlark.com/yuque/0/2020/png/2463114/1600618364450-b5f8e616-8e45-47a1-88c4-6e31675fbc11.png#align=left&display=inline&height=777&margin=%5Bobject%20Object%5D&name=image.png&originHeight=777&originWidth=1514&size=55950&status=done&style=none&width=1514)

3. 再次使用虚IP访问Haproxy状态页面，依旧可以访问

![image.png](https://cdn.nlark.com/yuque/0/2020/png/2463114/1600618448124-92a9c25e-70e1-4923-8f1b-46a14af5faf2.png#align=left&display=inline&height=608&margin=%5Bobject%20Object%5D&name=image.png&originHeight=608&originWidth=1915&size=126771&status=done&style=none&width=1915)
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## 修改集群配置

1. 进入Hive -> 配置 -> 搜索HiveServer2 Load Balancer，参数修改为虚 IP:端口号

![image.png](https://cdn.nlark.com/yuque/0/2020/png/2463114/1600618633304-871bcae6-b278-4eef-9055-d2b141628147.png#align=left&display=inline&height=803&margin=%5Bobject%20Object%5D&name=image.png&originHeight=803&originWidth=1896&size=132967&status=done&style=none&width=1896)

2. 进入Hue -> 配置 -> 搜索hue_safety_valve.ini，加如下配置,其中hive_server_host填写虚IP

[beeswax] hive_server_host=hostname hive_server_port=10001


3. 回到CM页面，重启相关服务

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## 测试Beeline和Hue

1. 将beeline连接串改为虚IP的连接串，连接HiveServer2
```shell
beeline -u "jdbc:hive2://load:10001/;principal=hive/load@FAYSON.COM"

image.png

  1. 使用Hue提交一个查询任务

image.png

  1. 至此基于Keepalived实现Haproxy高可用配置完成了