pacemaker+Haproxy实现集群负载均衡
本篇内容实现了pacemaker+Haproxy的简单集群负载均衡
高可用+负载均衡可查看：
https://blog.csdn.net/aaaaaab_/article/details/81408444
实验环境：
server2,server3:集群节点
server5,server6:后端服务器一、配置Haproxy
HAProxy 是一款提供高可用性、负载均衡以及基于TCP（第四层）和HTTP（第七层）应用的代理软件。
也是是一种高效、可靠、免费的高可用及负载均衡解决方案，非常适合于高负载站点的七层数据请求。
客户端通过HAProxy代理服务器获得站点页面，而代理服务器收到客户请求后根据负载均衡的规则将
请求数据转发给后端真实服务器。
同一客户端访问服务器，HAProxy保持回话的三种方案：
1 HAProxy将客户端ip进行Hash计算并保存，由此确保相同IP访问时被转发到同一真实服务器上。
2 HAProxy依靠真实服务器发送给客户端的cookie信息进行回话保持。
3 HAProxy保存真实服务器的session及服务器标识，实现会话保持功能。在server2：
[root@serve2 yum.repos.d]# yum install haproxy -y 安装haproxy
Loaded plugins: product-id, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Setting up Install Process
Package haproxy-1.4.24-2.el6.x86_64 already installed and latest version
Nothing to do
[root@serve2 yum.repos.d]# vim /etc/haproxy/haproxy.cfg 编辑主配置文件
[root@serve2 yum.repos.d]# cat /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 local2
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 65535
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 1m
timeout server 1m
timeout http-keep-alive 10s
timeout check 10s
maxconn 3000
stats uri /admin/stats 健康检查
monitor-uri /monitoruri 监控管理
#---------------------------------------------------------------------
# main frontend which proxys to the backends
#---------------------------------------------------------------------
frontend main *:5000
# acl url_static path_beg -i /static /images /javascript /stylesheets
# acl url_static path_end -i .jpg .gif .png .css .js
# use_backend static if url_static
bind 172.25.254.100:80 添加虚拟IP
default_backend static
#---------------------------------------------------------------------
# static backend for serving up images, stylesheets and such
#---------------------------------------------------------------------
backend static
balance roundrobin
server static 172.25.254.6:80 check 添加后端IP
server static 172.25.254.7:80 check
#---------------------------------------------------------------------
# round robin balancing between the various backends
#---------------------------------------------------------------------
backend app
balance roundrobin
server app1 127.0.0.1:5001 check
server app2 127.0.0.1:5002 check
server app3 127.0.0.1:5003 check
server app4 127.0.0.1:5004 check
[root@serve2 yum.repos.d]# ip addr add 172.25.254.100/24 dev eth0 添加虚拟IP
[root@serve2 yum.repos.d]# vim /etc/security/limits.conf
[root@serve2 yum.repos.d]# cat /etc/security/limits.conf| tail -n 1
haproxy - nofile 65535
[root@serve2 yum.repos.d]# /etc/init.d/haproxy start 打开服务
Starting haproxy: [ OK ]
[root@serve2 yum.repos.d]# ip addr 查看IP
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 52:54:00:ee:d7:80 brd ff:ff:ff:ff:ff:ff
inet 172.25.254.2/24 brd 172.25.254.255 scope global eth0
inet 172.25.254.100/24 scope global secondary eth0
inet6 fe80::5054:ff:feee:d780/64 scope link
valid_lft forever preferred_lft forever
server1上Haproxy实现轮询： 测试
配置后端服务器server5：
[root@server5 ~]# yum install httpd -y 安装阿帕其
Loaded plugins: product-id, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Setting up Install Process
Package httpd-2.2.15-29.el6_4.x86_64 already installed and latest version
Nothing to do
[root@server5 ~]# cd /var/www/html/ 编写访问目录
[root@server5 html]# ls
[root@server5 html]# vim index.html
[root@server5 html]# cat index.html
server5
[root@server5 html]# /etc/init.d/httpd start 打开阿帕其
Starting httpd: httpd: Could not reliably determine the server's fully qualified domain name, using 172.25.254.5 for ServerName
[ OK ]
[root@server5 html]# /etc/init.d/httpd restart 重启阿帕其
Stopping httpd: [ OK ]
Starting httpd: httpd: Could not reliably determine the server's fully qualified domain name, using 172.25.254.5 for ServerName
[ OK ]
配置后端服务器server6：
[root@server6 ~]# yum install httpd -y 安装阿帕其
Loaded plugins: product-id, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
rhel-source | 3.9 kB 00:00
Setting up Install Process
Package httpd-2.2.15-29.el6_4.x86_64 already installed and latest version
Nothing to do
[root@server6 ~]# cd /var/www/html/ 编写访问目录
[root@server6 html]# ls
[root@server6 html]# vim index.html
[root@server6 html]# cat index.html
server6
[root@server6 html]# /etc/init.d/httpd start 打开阿帕其
Starting httpd: httpd: Could not reliably determine the server's fully qualified domain name, using 172.25.254.6 for ServerName
[ OK ]
[root@server6 html]# /etc/init.d/httpd restart重启阿帕其
Stopping httpd: [ OK ]
Starting httpd: httpd: Could not reliably determine the server's fully qualified domain name, using 172.25.254.6 for ServerName
[ OK ]
在真机写入解析在浏览器测试可以正常轮询：
在浏览器测试健康检查：
在浏览器测试监控界面：
在server3和server2作同样的配置防止一个节点坏掉系统崩溃：
[root@serve3 ~]# yum install haproxy -y 安装haproxy服务
[root@serve3 ~]# scp server2:/etc/haproxy/haproxy.cfg /etc/haproxy/
root@server2's password:
haproxy.cfg 100% 3301 3.2KB/s 00:00
[root@serve3 ~]# ip addr add 172.25.254.100/24 dev eth0 添加虚拟IP
[root@serve3 ~]# ip addr
1: lo: mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 52:54:00:42:fc:3a brd ff:ff:ff:ff:ff:ff
inet 172.25.254.3/24 brd 172.25.254.255 scope global eth0
inet 172.25.254.100/24 scope global secondary eth0
inet6 fe80::5054:ff:fe42:fc3a/64 scope link
valid_lft forever preferred_lft forever
[root@serve3 ~]# 二、配置pacemaker：
Pacemaker是一个集群资源管理器。它利用集群基础构件
（OpenAIS 、heartbeat或corosync）提供的消息和成
员管理能力来探测并从节点或资源级别的故障中恢复，以实现
群集服务（亦称资源）的最大可用性。
Corosync是集群管理套件的一部分，它在传递信息的时候可以
通过一个简单的配置文件来定义信息传递的方式和协议等。
传递心跳信息和集群事务信息，pacemaker工作在资源分配层，提供资
源管理器的功能，并以crmsh这个资源配置的命令接口来配置资源
在server2:
[root@serve2 ~]# yum install pacemaker corosync -y 安装pacemaker
[root@serve2 ~]# cp /etc/corosync/corosync.conf.example /etc/corosync/corosync.conf
[root@serve2 ~]# rpm -ivh crmsh-1.2.6-0.rc2.2.1.x86_64.rpm --nodeps 安装crm
warning: crmsh-1.2.6-0.rc2.2.1.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 7b709911: NOKEY
Preparing... ########################################### [100%]
1:crmsh ########################################### [100%] 
[root@serve2 ~]# vim /etc/corosync/corosync.conf 修改配置文件
[root@serve2 ~]# scp crmsh-1.2.6-0.rc2.2.1.x86_64.rpm server3:/root 将配置文件传到server3
root@server3's password:
crmsh-1.2.6-0.rc2.2.1.x86_64.rpm 100% 483KB 483.4KB/s 00:00
[root@serve2 ~]# /etc/init.d/pacemaker start 开启服务
[root@serve2 ~]# scp /etc/corosync/corosync.conf server3:/etc/corosync/
root@server3's password:
corosync.conf 100% 642 0.6KB/s 00:00
[root@serve2 ~]# /etc/init.d/corosync start 开启服务
Starting Corosync Cluster Engine (corosync): [ OK ]
[root@serve2 ~]# crm 只有server2状态
crm(live)# status
Last updated: Fri Aug 3 20:47:36 2018
Last change: Fri Aug 3 20:45:38 2018 via crmd on serve2
Stack: classic openais (with plugin)
Current DC: serve2 - partition WITHOUT quorum
Version: 1.1.10-14.el6-368c726
1 Nodes configured, 2 expected votes
0 Resources configured
Online: [ serve2 ]
crm(live)# quit
bye
[root@serve2 ~]# crm status
Last updated: Fri Aug 3 21:26:49 2018
Last change: Fri Aug 3 21:10:22 2018 via crmd on serve2
Stack: classic openais (with plugin)
Current DC: serve2 - partition with quorum
Version: 1.1.10-14.el6-368c726
2 Nodes configured, 2 expected votes
0 Resources configured
Online: [ serve2 serve3 ]
[root@serve2 ~]# crm node standby 将server2节点关闭
在server3：
[root@serve3 ~]# yum install pacemaker corosync -y 安装pacemaker安装包
[root@serve3 ~]# rpm -ivh crmsh-1.2.6-0.rc2.2.1.x86_64.rpm --nodeps
error: open of crmsh-1.2.6-0.rc2.2.1.x86_64.rpm failed: No such file or directory
[root@serve3 ~]# rpm -ivh crmsh-1.2.6-0.rc2.2.1.x86_64.rpm --nodeps
warning: crmsh-1.2.6-0.rc2.2.1.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 7b709911: NOKEY
Preparing... ########################################### [100%]
1:crmsh ########################################### [100%]
[root@serve3 ~]# /etc/init.d/corosync start 打开服务
Starting Corosync Cluster Engine (corosync): [ OK ]
[root@serve3 ~]# /etc/init.d/pacemaker start 打开服务
[root@serve3 ~]# crm status 查看状态server2和server3工作
Last updated: Fri Aug 3 21:25:33 2018
Last change: Fri Aug 3 21:10:22 2018 via crmd on serve2
Stack: classic openais (with plugin)
Current DC: serve2 - partition with quorum
Version: 1.1.10-14.el6-368c726
2 Nodes configured, 2 expected votes
0 Resources configured
Online: [ serve2 serve3 ]
[root@serve3 ~]# crm status server2关闭之后
Last updated: Fri Aug 3 21:27:18 2018
Last change: Fri Aug 3 21:27:12 2018 via crm_attribute on serve2
Stack: classic openais (with plugin)
Current DC: serve2 - partition with quorum
Version: 1.1.10-14.el6-368c726
2 Nodes configured, 2 expected votes
0 Resources configured
Node serve2: standby
Online: [ serve3 ]
[root@serve3 ~]# crm node standby 将server3关闭没有节点工作
[root@serve3 ~]# crm status
Last updated: Fri Aug 3 21:29:11 2018
Last change: Fri Aug 3 21:29:07 2018 via crm_attribute on serve2
Stack: classic openais (with plugin)
Current DC: serve2 - partition with quorum
Version: 1.1.10-14.el6-368c726
2 Nodes configured, 2 expected votes
0 Resources configured
Node serve2: standby
Node serve3: standby