Corosync+pacemaker实现对haproxy的高可用

一、架构模型

通过Haproxy实现对web服务的负载均衡及健康检查，pacemaker实现haproxy的高可用,corosync实现心跳信息的传递

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。

pacemaker和corosync，后者用于心跳检测，前者用于资源转移。两个结合起来使用，可以实现对高可用架构的自动管理。 心跳检测是用来检测服务器是否还在提供服务，只要出现异常不能提供服务了，就认为它挂掉了。 当检测出服务器挂掉之后，就要对服务资源进行转移。
CoroSync是运行于心跳层的开源软件， PaceMaker是运行于资源转移层的开源软件。

二、配置

实验环境：

主机	ip	服务
server1	172.25.1.1	corosync，pacemaker，haproxy
server2	172.25.1.2	httpd
server3	172.25.1.3	httpd
server4	172.25.1.4	corosync,pacemaker,haproxy

haproxy的安装配置

压缩包解压并构建rpm包

tar zxf haproxy-1.6.11.tar.gz     #解压tar包
yum install rpm-build -y           #安装rpm包制作工具
rpmbuild -tb haproxy-1.6.11.tar.gz    #将其制作为rpm包
​
cd /root/rpmbuild/RPMS/x86_64/
rpm -qpl haproxy-1.6.11-1.x86_64.rpm  （查看下载后得到的相关文件）
rpm -ivh haproxy-1.6.11-1.x86_64.rpm （安装）
​
cd /mnt/haproxy-1.6.11/examples
cp content-sw-sample.cfg /etc/haproxy/haproxy.cfg    将模板中的配置文件移到对应目录下

添加haproxy用户和组

grep 200 /etc/passwd
groupadd -g 200 haproxy    建立一个haproxy组
useradd -u 200 -g 200 -M haproxy
id haproxy

haproxy配置负载均衡

[root@server1 haproxy]# cat haproxy.cfg 
#
# This is a sample configuration. It illustrates how to separate static objects
# traffic from dynamic traffic, and how to dynamically regulate the server load.
#
# It listens on 192.168.1.10:80, and directs all requests for Host 'img' or
# URIs starting with /img or /css to a dedicated group of servers. URIs
# starting with /admin/stats deliver the stats page.
#

global
        maxconn         10000
        stats socket    /var/run/haproxy.stat mode 600 level admin
        log             127.0.0.1 local0
        uid             200
        gid             200
        chroot          /var/empty
        daemon

# The public 'www' address in the DMZ
frontend public
        bind            *:80 name clear
        #bind            192.168.1.10:443 ssl crt /etc/haproxy/haproxy.pem
        mode            http
        log             global
        option          httplog
        option          dontlognull
        monitor-uri     /monitoruri
        maxconn         8000
        timeout client  30s

        stats uri       /admin/stats
        #use_backend     static if { hdr_beg(host) -i img }
        #use_backend     static if { path_beg /img /css   }
        default_backend static

# The static backend backend for 'Host: img', /img and /css.
backend static
        mode            http
        balance         roundrobin
        option prefer-last-server
        retries         2
        option redispatch
        timeout connect 5s
        timeout server  5s
        #option httpchk  HEAD /favicon.ico
        server          statsrv1 172.25.1.2:80 check inter 1000
        server          statsrv2 172.25.1.3:80 check inter 1000
	    server		backup 172.25.1.1:8080 backup

启动服务,进行测试（server1与server4都需要执行安装配置）

[root@server1 ~]# /etc/init.d/haproxy start #测试完以后一定要关闭，之后pacemaker会控制haproxy的启动

​

corosync安装配置

corosync安装

[root@server1 ~]# yum install -y corosync   #需配置高可用yum源
[root@server1 ~]# yum install -y crmsh-1.2.6-0.rc2.2.1.x86_64.rpm  pssh-2.3.1-2.1.x86_64.rpm 
#crm命令安装

配置

cp /etc/corosync/corosync.conf.example /etc/corosync/corosync.conf
vim /etc/corosync/corosync.conf
#Please read the corosync.conf.5 manual page
compatibility: whitetank

service {
     ver:0                    ###指定版本,0 时自动启动 pacemaker
     name:pacemaker
}

aisexec {                 ###指定启动 ais 功能时以那个用户的身份去运行,可不写   
     user:root
     group:root
}
totem {
        version: 2    #版本唯一，只有2合法
        secauth: off    #集群认证
        threads: 0   #线程数，可加快广播或组播，也可以加快secauth
        interface {
                ringnumber: 0   #当有多块网卡时需指定
                bindnetaddr: 172.25.12.0            #绑定网络地址段
                mcastaddr: 226.94.1.1               #组播地址
                mcastport: 5405                     #组播端口
                ttl: 1            #超时时间
        }
}

corosync启动

server1和server4启动corosync （server1与server4都需要安装配置）

执行crm status #查看server1和server4状态

[root@server1 corosync]# crm status
Last updated: Sun Oct  7 18:24:24 2018
Last change: Sun Oct  7 16:12:18 2018 via cibadmin on server1
Stack: classic openais (with plugin)
Current DC: server4 - partition with quorum
Version: 1.1.10-14.el6-368c726
2 Nodes configured, 2 expected votes   #两个节点，两个有效票数
0 Resources configured


Online: [ server1 server4 ]  #server1与server4已经实现心跳传递

pacemaker安装配置

安装

    [root@server1 ~]# yum install -y  pacemaker

配置

crmsh利用资源配置的命令接口来配置资源

查看当前集群系统所支持的类：
 [root@server1 corosync]# crm ra classes
 lsb
 ocf / heartbeat pacemaker
 service
 stonith

 Crm配置Haproxy
    如果想删除配置crm resource到里面stop掉，然后在configure中执行delete+名字即可进行删除！！！

使用Crm来配置资源

crm的简单使用

crm(live)# help

This is crm shell, a Pacemaker command line interface.

Available commands:

	cib              manage shadow CIBs
	resource         resources management
	configure        CRM cluster configuration
	node             nodes management
	options          user preferences
	history          CRM cluster history
	site             Geo-cluster support
	ra               resource agents information center
	status           show cluster status
	help,?           show help (help topics for list of topics)
	end,cd,up        go back one level
	quit,bye,exit    exit the program
#crm的help命令为全状态命令,无论进入到那个模块里面都可以使用help来查看帮助文档
crm(live)# ra  #进入资源代理模块
crm(live)ra# help #可以看到里面有很多子命令

This level contains commands which show various information about
the installed resource agents. It is available both at the top
level and at the `configure` level.

Available commands:

	classes          list classes and providers
	list             list RA for a class (and provider)
	meta             show meta data for a RA
	providers        show providers for a RA and a class
	help             show help (help topics for list of topics)
	end              go back one level
	quit             exit the program
crm(live)ra# classes   #classes可以查看支持的RA类型
lsb
ocf / heartbeat pacemaker
service
stonith
crm(live)ra# providers IPaddr2   #可以查看RA属于那个类型
heartbeat
crm(live)ra# meta ocf:heartbeat:IPaddr2  #查看对应RA的原数据,下面仅对此RA做了简单摘要
ip* (string): IPv4 or IPv6 address
    The IPv4 (dotted quad notation) or IPv6 address (colon hexadecimal notation)
    example IPv4 "192.168.1.1".
    example IPv6 "2001:db8:DC28:0:0:FC57:D4C8:1FFF".
nic (string): Network interface
    The base network interface on which the IP address will be brought
    online. 
    If left empty, the script will try and determine this from the
    routing table.
    
    Do NOT specify an alias interface in the form eth0:1 or anything here;
    rather, specify the base interface only.
    If you want a label, see the iflabel parameter.
    
    Prerequisite:
    
    There must be at least one static IP address, which is not managed by
    the cluster, assigned to the network interface.
    If you can not assign any static IP address on the interface,
    modify this kernel parameter:
    
    sysctl -w net.ipv4.conf.all.promote_secondaries=1 # (or per device)
Operations' defaults (advisory minimum):

    start         timeout=20s
    stop          timeout=20s
    status        timeout=20s interval=10s
    monitor       timeout=20s interval=10s

执行crm，进入crm命令

crm(live)# configure   #进入配置
crm(live)configure# show    # 查看配置所有信息
node server1
node server4
property $id="cib-bootstrap-options" \
    dc-version="1.1.10-14.el6-368c726" \
    cluster-infrastructure="classic openais (with plugin)" \
    expected-quorum-votes="2" \  
crm(live)configure# property stonith-enabled=False
#因为没有定义stonith设备,因为需要关闭stonith
crm(live)configure# verify 
crm(live)configure# primitive vip ocf:heartbeat:IPaddr2 params ip=172.25.1.100 nic=eth0 cidr_netmask=24 op monitor interval=1min 
#配置vip资源，RA使用ocf类型中heartbeat里面的IPaddr2脚本，params后为传入的参数，vip为172.25.1.100，nic为绑定的网卡名,cidr_netmask=24子网掩码，op后为修改默认的属性值
crm(live)configure# verify 
crm(live)configure# commit  # 提交
crm(live)# configure 
crm(live)configure# primitive haporxy lsb:haproxy op monitor interval=1min
crm(live)configure# property no-quorum-policy=ignore  # 忽略节点数检测，因为如果是一节节点的时候服务会出错，因为集群一般都是两个或者或两个以上
crm(live)configure# verify 
crm(live)configure# commit     # 提交    
crm(live)configure# group hagroup vip haporxy  #将vip和harpoxy绑定
crm(live)configure# verify 
crm(live)configure# commit
crm(live)configure# exit
bye

crm_mon监控命令可以查看集群中的服务情况

查看加入的配置：

[root@server1 corosync]# crm configure show
primitive haporxy lsb:haproxy \
	op monitor interval="1min"
primitive vip ocf:heartbeat:IPaddr2 \
	params ip="172.25.1.100" nic="eth0" cidr_netmask="24" \
	op monitor interval="1min"
group hagroup vip haporxy
property $id="cib-bootstrap-options" \
	dc-version="1.1.10-14.el6-368c726" \
	cluster-infrastructure="classic openais (with plugin)" \
	expected-quorum-votes="2" \
	stonith-enabled="False" \
	no-quorum-policy="ignore"

查看集群配置：

[root@server1 corosync]# crm status
Last updated: Sun Oct  7 18:31:15 2018
Last change: Sun Oct  7 16:12:18 2018 via cibadmin on server1
Stack: classic openais (with plugin)
Current DC: server4 - partition with quorum
Version: 1.1.10-14.el6-368c726
2 Nodes configured, 2 expected votes
3 Resources configured


Online: [ server1 server4 ]

 Resource Group: hagroup
     vip	(ocf::heartbeat:IPaddr2):	Started server4 
     haporxy	(lsb:haproxy):	Started server4 

crm node standby server1 （下线server1节点）
crm node online server1（server1上线）

fence安装与配置

(实验中fence安装在function1中)

安装

[root@foundation1 ~]# yum install fence-virtd.x86_64 fence-virtd-libvirt.x86_64 fence-virtd-multicast.x86_64 -y

生成随机数

mkdir /etc/cluster
dd if=/dev/urandom of=/etc/cluster/fence_xvm.key bs=128 count=1             ###生成随机数key

编辑fence的配置文件

[root@foundation1 Desktop]# fence_virtd -c
Module search path [/usr/lib64/fence-virt]: 

Available backends:
    libvirt 0.1
Available listeners:
    multicast 1.2

Listener modules are responsible for accepting requests
from fencing clients.

Listener module [multicast]:                  ###模式

The multicast listener module is designed for use environments
where the guests and hosts may communicate over a network using
multicast.

The multicast address is the address that a client will use to
send fencing requests to fence_virtd.

Multicast IP Address [225.0.0.12]:             ###广播地址
Using ipv4 as family.

Multicast IP Port [1229]:             ###端口，可以自行指定

Setting a preferred interface causes fence_virtd to listen only
on that interface.  Normally, it listens on all interfaces.
In environments where the virtual machines are using the host
machine as a gateway, this *must* be set (typically to virbr0).
Set to 'none' for no interface.

Interface [br0]: br0            ###此处根据自己的网卡名进行设置

The key file is the shared key information which is used to
authenticate fencing requests.  The contents of this file must
be distributed to each physical host and virtual machine within
a cluster.

Key File [/etc/cluster/fence_xvm.key]: 

Backend modules are responsible for routing requests to
the appropriate hypervisor or management layer.

Backend module [libvirt]: 

Configuration complete.

=== Begin Configuration ===
fence_virtd {
	listener = "multicast";
	backend = "libvirt";
	module_path = "/usr/lib64/fence-virt";
}

listeners {
	multicast {
		key_file = "/etc/cluster/fence_xvm.key";
		address = "225.0.0.12";
		interface = "br0";
		family = "ipv4";
		port = "1229";
	}

}

backends {
	libvirt {
		uri = "qemu:///system";
	}

}

=== End Configuration ===
Replace /etc/fence_virt.conf with the above [y/N]? y    #替换原有文件
systemctl restart fence_virtd.service                           ###重启fence服务，其配置文件在/etc/fence_virt.conf

将生成的key发送到server1和server4中

 scp /etc/cluster/fence_xvm.key [email protected]:/etc/cluster/
 scp /etc/cluster/fence_xvm.key [email protected]:/etc/cluster/

在server1和server4上执行命令stonith_admin -I

查看是否有fence代理:fence_xvm，如果没有需要安装下面软件：

[root@server1 corosync]#   yum  install  fence-virt-0.2.3-15.el6.x86_64    
[root@server1 corosync]# stonith_admin -I
 fence_xvm
 fence_virt
 fence_pcmk
 fence_legacy
4 devices found

向集群中添加服务

在server4上添加集群服务信息（其实在一台后端服务器可以添加所有的服务配置，这样做只是为了说明这两个节点之间是同步的，在服务提交后可以同步两者之间的信息）
crm(live)# crm
crm(live)configure# primitive vmfence stonith:fence_xvm params pcmk_host_map="server1:test1;server4:test4" op monitor interval=1min
# 添加fence服务处理故障的节点server1:test1  server1是主机名，test1是真实的虚拟机名称
property stonith-enabled=true  # 添加fence设备
crm(live)configure# verity
crm(live)configure# commit  # 提交
crm(live)# configure 
crm(live)configure# show
node server1
node server4 \
    attributes standby="off"
primitive haporxy lsb:haproxy \
    op monitor interval="1min"
primitive vip ocf:heartbeat:IPaddr2 \
    params ip="172.25.1.100" cidr_netmask="24" \
    op monitor interval="1min"
primitive vmfence stonith:fence_xvm \
    params pcmk_host_map="server1:test1;server4:test4" \
    op monitor interval="1min"
group hagroup vip haporxy
property $id="cib-bootstrap-options" \
    dc-version="1.1.10-14.el6-368c726" \
    cluster-infrastructure="classic openais (with plugin)" \
    expected-quorum-votes="2" \
    stonith-enabled="true" \
    no-quorum-policy="ignore"

​

[root@server1 ~]# /etc/init.d/corosync restart
[root@server4 ~]# /etc/init.d/corosync restart

​

查看集群状态

​
[root@server1 corosync]# crm status
Last updated: Sun Oct  7 18:37:04 2018
Last change: Sun Oct  7 16:12:18 2018 via cibadmin on server1
Stack: classic openais (with plugin)
Current DC: server4 - partition with quorum
Version: 1.1.10-14.el6-368c726
2 Nodes configured, 2 expected votes
3 Resources configured


Online: [ server1 server4 ]

 Resource Group: hagroup
     vip	(ocf::heartbeat:IPaddr2):	Started server4 
     haporxy	(lsb:haproxy):	Started server4 
 	 vmfence	(stonith:fence_xvm):	Started server1

​

测试

[root@server4 ~]# echo c > /proc/sysrq-trigger

模拟server4内核崩溃，等一会server4便会自动重启，并且资源转移到server1中