rhcs是用來實現高可用的一個紅帽套件。

下來我將介紹如何安裝配置rhcs和用rhcs實現httpd的高可用。

作業系統版本：redhat6.5

master：server1

slave：server2

在server1上搭建web管理介面

實驗之前給兩臺節點上安裝httpd

rhcs的安裝

1.配置yum源，安裝相應的軟體

#ricci是master和slave都要安裝

#配置yum源

[[email protected] ~]# vim /etc/yum.repos.d/rhel-source.repo

[rhel-source]
name=Red Hat Enterprise Linux $releasever - $basearch - Source
baseurl=http://172.25.60.250/rhel6.5
enabled=1
igpgcheck=0

[HighAvailability]
name=HighAvailability
baseurl=http://172.25.60.250/rhel6.5/HighAvailability
gpgcheck=0

[LoadBalancer]
name=LoadBalancer
baseurl=http://172.25.60.250/rhel6.5/LoadBalancer
gpgcheck=0


[ResilientStorage]
name=ResilientStorage
baseurl=http://172.25.60.250/rhel6.5/ResilientStorage
gpgcheck=0

[ScalableFileSystem]
name=ScalableFileSystem
baseurl=http://172.25.60.250/rhel6.5/ScalableFileSystem
gpgcheck=0
 

#安裝ricci，開啟ricci後會出現11111埠

[[email protected] ~]# yum install ricci -y
[[email protected] ~]# passwd ricci
[[email protected] ~]# /etc/init.d/ricci start
[[email protected] ~]# chkconfig ricci on
[[email protected] ~]# netstat -antlp
tcp        0      0 :::11111                    :::*                        LISTEN      1205/ricci          

 

#luci為rhcs的web管理介面
[[email protected] ~]# yum install -y luci
[[email protected] ~]# chkconfig luci on
[[email protected] ~]# /etc/init.d/luci start

2.瀏覽器訪問檢視

訪問 https://172.25.60.1:8084 ，會出現以下頁面

使用者  作業系統使用者

密碼 系統的密碼

登陸後會出現以下介面

點選Manage Clusters，上圖紅框，新增節點，我的節點是server1和server2，因為勾選了加入節點後重啟，所以server1和server2加入後會重新啟動。

新增之後

此時，可以在結點上使用以下命令進行檢視

腦裂：當兩臺高可用節點網路之間出現問題時或者master夯住時，master給slave主機發送的心跳slave接收不到，此時就會通過選舉機制在slave中重新選舉出master接管舊的master的資源，但是當網路恢復或者舊的master恢復之後，舊的master會繼續履行master的職責，就會和新的master進行資源的爭奪，出現腦裂。為了防止腦裂，就出現了fence。

fence：當master出現問題但沒有掛掉時，將master強制掛掉，新的master產生之後就會出現腦裂現象。

fence新增

#fence分為外部fence和內部fence，我以外部fence為例，因為兩臺高可用節點是虛擬機器，所以我用物理機充當fence裝置

[[email protected] ~]# systemctl status libvirtd
[[email protected] ~]# rpm -qa | grep fence
[[email protected] rhcl-redhat]# yum install fence-virtd-0.3.2-2.el7.x86_64  fence-virtd-libvirt-0.3.2-2.el7.x86_64 fence-virtd-multicast-0.3.2-2.el7.x86_64 -y

[[email protected] rhcl-redhat]# cd /etc/
[[email protected] etc]# fence_virtd -c
Module search path [/usr/lib64/fence-virt]: 

Available backends:
    libvirt 0.1
Available listeners:
    multicast 1.2
    serial 0.4

Listener modules are responsible for accepting requests
from fencing clients.

Listener module [multicast]:     

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]: 

Using ipv4 as family.

Multicast IP Port [1229]: 

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 [virbr0]: br0

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

}

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

}

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

=== End Configuration ===

Replace /etc/fence_virt.conf with the above [y/N]? y

#以上配置都記錄在/etc/fence_virt.conf檔案中
[[email protected] etc]# cat /etc/fence_virt.conf 
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";
	}

}

#第一次做時是沒有該目錄，需要自己建立
[[email protected] etc]# mkdir /etc/cluster 
[[email protected] etc]# cd clust
#建立了一個key
[[email protected] cluster]# dd if=/dev/urandom
  of=fence_xvm.key bs=128 count=1 
[[email protected] cluster]# ls
fence_xvm.key

#將key傳送給高可用節點
[[email protected] cluster]# scp fence_xvm.key  server1:/etc/cluster/
[[email protected] cluster]# scp fence_xvm.key  server4:/etc/cluster/

訪問 https://172.25.60.1:8084，rhcs中新增fence

#新增fence裝置，根據自己需要新增

#給兩個節點新增fence，我的節點是虛擬機器，Domain處新增的是虛擬機器的UUID

#新增完之後

fence新增成功，下來新增服務

#建立叢集

#新增ViP資源

#新增指令碼資源，及指令碼路徑

#新增服務組叢集

#給服務組叢集中新增資源

#在節點上使用以下命令檢視，資源在哪臺節點上

#master上就會新增一個vip資源

#瀏覽器訪問vip

#刪掉master上的vip，由於fence的存在，資源就會轉移到slave上