Pacemaker高可用环境实践

配置两台虚拟机来模拟安装整个过程，通过corosync定义两个资源ipaddr和httpd来说明在crm命令行里如何定义资源。

host1.zyg.com     192.168.5.101
host2.zyg.com     192.168.5.102

提供web服务的虚拟IP
Ipaddr: 192.168.5.10


 先关闭selinux和防火墙并进行时间同步

两台都需要做的：

[root@host1 ~]# yum install corosync（负责心跳） pacemaker（资源管理） pcs resource-agents

[root@host1 ~]# systemctl start pcsd

[root@host1 ~]# passwd hacluster

[root@host1 ~]# pcs cluster auth host1.zyg.com
Username: hacluster
Password: 123
host1.zyg.com: Authorized

[root@host1 ~]# pcs cluster auth host2.zyg.com
Username: hacluster
Password: 123
host2.zyg.com: Authorized

在host1.zyg.com上操作；将两个虚拟机加入到集群中；

[root@host1 ~]# pcs cluster setup --start --name mycluster host1.zyg.com host2.zyg.com --transport udpu

禁用爆头功能和仲裁功能；

[root@host1 ~]# pcs property set stonith-enabled=false
[root@host1 ~]# pcs property set no-quorum-policy=ignore

查看集群状态

[root@host1 ~]# pcs status

这职位开机自启动；

[root@host1 ~]# systemctl enable pcsd
[root@host1 ~]# systemctl enable corosync
[root@host1 ~]# systemctl enable pacemaker

查看可用资源；

[root@host1 ~]# pcs resource list

Pacemaker 的资源主要有两类，即 LSB 和 OCF(Open Cluster Framework)。其中 LSB 即 linux 标准服务，通常就是 /etc/init.d 目录下那些脚本。Pacemaker 可以用这些脚本来启停服务。另一类 OCF 实际上是对 LSB 服务的扩展，增加了一些高可用集群管理的功能如故障监控等和更多的元信息。要让 pacemaker 可以很好的对服务进行高可用保障就得实现一个 OCF 资源。

添加IP资源；

[root@host1 ~]# pcs resource create VirtualIP ocf:heartbeat:IPaddr2 ip=192.168.5.10 cidr_netmask=32 nic=eth0 op monitor interval=30s

添加webserver资源；

[root@host1 ~]# pcs resource create WebServer systemd:httpd op monitor interval=20s timeout=40s

这里会出现资源放在两台虚拟机上的情况；

可以通过这条命令建立约束；

[root@host1 ~]# pcs constraint colocation add WebServer with VirtualIP INFINITY

 

测试：

[root@sxb-1 ~]# ip addr s
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:e2:62:04 brd ff:ff:ff:ff:ff:ff
    inet 192.168.88.105/24 brd 192.168.88.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.88.200/32 brd 192.168.88.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fee2:6204/64 scope link 
       valid_lft forever preferred_lft forever
[root@sxb-1 ~]# systemctl status httpd
● httpd.service - Cluster Controlled httpd
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; disabled; vendor preset: disabled)
  Drop-In: /run/systemd/system/httpd.service.d
           └─50-pacemaker.conf
   Active: active (running) since Thu 2019-08-01 07:46:44 EDT; 2min 1s ago
     Docs: man:httpd(8)
           man:apachectl(8)
 Main PID: 4301 (httpd)
   Status: "Total requests: 0; Current requests/sec: 0; Current traffic:   0 B/sec"
   CGroup: /system.slice/httpd.service
           ├─4301 /usr/sbin/httpd -DFOREGROUND
           ├─4302 /usr/sbin/httpd -DFOREGROUND
           ├─4303 /usr/sbin/httpd -DFOREGROUND
           ├─4304 /usr/sbin/httpd -DFOREGROUND
           ├─4305 /usr/sbin/httpd -DFOREGROUND
           └─4306 /usr/sbin/httpd -DFOREGROUND

Aug 01 07:46:44 105.com systemd[1]: Starting Cluster Controlled httpd...
Aug 01 07:46:44 105.com systemd[1]: Started Cluster Controlled httpd.

我们停掉host1的httpd服务；

[root@sxb-2 ~]# ip addr s
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:f1:e4:7b brd ff:ff:ff:ff:ff:ff
    inet 192.168.88.106/24 brd 192.168.88.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.88.200/32 brd 192.168.88.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fef1:e47b/64 scope link 
       valid_lft forever preferred_lft forever