# 高可用集群类型
– 主动-被动集群：一个节点为活动节点，其他节点为备用节点
– 主动-主动集群：多个节点同时提供服务
– N+1集群：N个服务节点，1个备用节点
– N-to-1集群：多个服务节点共享一个备用节点

# 高可用集群指标
– 可用性：系统正常运行的时间比例
– 可靠性：系统在一定时间内正常运行的概率
– 可维护性：系统从故障中恢复的速度
– 故障转移时间：从故障发生到服务恢复的时间

# 集群规模
– 2节点集群：基本高可用配置
– 3节点集群：推荐配置，提供更好的可靠性
– 多节点集群：适用于大规模应用

# 集群拓扑
– 环形拓扑：所有节点通过环连接
– 星型拓扑：所有节点连接到中心节点
– 网状拓扑：每个节点都与其他节点直接连接

# 资源分配策略
– 主从模式：一个节点为主节点，其他为从节点
– 负载均衡模式：多个节点同时提供服务
– 故障转移模式：当主节点故障时，从节点接管

# 服务器要求
– 相同配置：所有节点硬件配置应相同
– 冗余电源：避免电源故障
– 冗余网络：多网卡配置
– 足够的内存和CPU：满足应用需求

# 存储要求
– 共享存储：用于存储数据
– 冗余存储：RAID配置
– 备份存储：定期备份数据

# 网络要求
– 专用心跳网络：用于节点间通信
– 业务网络：用于客户端访问
– 管理网络：用于集群管理

# 网络架构
– 心跳网络：单独的网络，用于节点间通信
– 业务网络：用于客户端访问
– 管理网络：用于集群管理

# 网络配置
– 静态IP：所有节点使用静态IP
– 网络隔离：使用VLAN隔离不同网络
– 网络冗余：多网卡绑定
– 网络监控：监控网络状态

# 网络安全
– 防火墙：限制网络访问
– 加密通信：加密节点间通信
– 访问控制：限制管理网络访问

# 在所有节点上安装集群组件
$ sudo dnf install -y pacemaker corosync pcs fence-agents-all

# 启动pcsd服务
$ sudo systemctl start pcsd
$ sudo systemctl enable pcsd

# 设置hacluster用户密码
$ sudo passwd hacluster
Changing password for user hacluster.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

# 在所有节点上认证
$ sudo pcs host auth node1 node2 node3 -u hacluster
Password for hacluster@node1:
node1: Authorized
node2: Authorized
node3: Authorized

# 创建集群
$ sudo pcs cluster setup –name fgedu-cluster node1 node2 node3
Destroying cluster on更多学习教程公众号风哥教程itpux_com nodes: node1, node2, node3…
node1: Stopping Cluster (pacemaker)…
node2: Stopping Cluster (pacemaker)…
node3: Stopping Cluster (pacemaker)…
node1: Successfully destroyed cluster
node2: Successfully destroyed cluster
node3: Successfully destroyed cluster
Sending ‘pacemaker_remote authkey’ to ‘node1’, ‘node2’, ‘node3’
node1: successful distribution of the file ‘pacemaker_remote authkey’
node2: successful distribution of the file ‘pacemaker_remote authkey’
node3: successful distribution of the file ‘pacemaker_remote authkey’
Sending cluster config files to the nodes…
node1: Succeeded
node2: Succeeded
node3: Succeeded
Synchronizing pcsd certificates on nodes node1, node2, node3…
node1: Success
node2: Success
node3: Success
Restarting pcsd on the nodes…
node1: Success
node2: Success
node3: Success

# 启动集群
$ sudo pcs cluster start –all
node1: Starting Cluster (corosync)…
node2: Starting Cluster (corosync)…
node3: Starting Cluster (corosync)…
node1: Starting Cluster (pacemaker)…
node2: Starting Cluster (pacemaker)…
node3: Starting Cluster (pacemaker)…

# 查看集群状态
$ sudo pcs status
Cluster name: fgedu-cluster
Cluster Summary:
* Stack: corosync
* Current DC: node1 (version 2.1.5-9.el9_3.1)
* 3 nodes configured
* 0 resources configured

Online: [ node1 node2 node3 ]

# 创建VIP资源
$ sudo pcs resource create virtual-ip ocf:heartbeat:IPaddr2 \
ip=192.168.1.100 \
cidr_netmask=24 \
op monitor interval=30s

# 创建Web服务资源
$ sudo pcs resource create web-server systemd:httpd \
op monitor interval=30s

# 创建数据库资源
$ sudo pcs resource create mysql-server systemd:mysqld \
op monitor interval=30s

# 查看资源状态
$ sudo pcs status
Cluster name: fgedu-cluster
Cluster Summary:
* Stack: corosync
* Current DC: node1 (version 2.1.5-9.el9_3.1)
* 3 nodes configured
* 3 resources configured

Online: [ node1 node2 node3 ]

Full list of resources:
virtual-ip (ocf::heartbeat:IPaddr2): Started node1
web-server (systemd:httpd): Started node1
mysql-server (systemd:mysqld): Started node1

# 创建资源组
$ sudo pcs resource group add web-group virtual-ip web-server

# 查看资源组状态
$ sudo pcs status
Cluster name: fgedu-cluster
Cluster Summary:
* Stack: corosync
* Current DC: node1 (version 2.1.5-9.el9_3.1)
* 3 nodes configured
* 3 resources configured

Online: [ node1 node2 node3 ]

Full list of resources:
Resource Group: web-group
virtual-ip (ocf::heartbeat:IPaddr2): Started node1
web-server (systemd:httpd): Started node1
mysql-server (systemd:mysqld): Started node1

# 创建资源约束
$ sudo pcs constraint colocation add mysql-server with web-group INFINITY
$ sudo pcs constraint order web-group then mysql-server

# 查看约束
$ sudo pcs constraint
Location Constraints:
Ordering Constraints:
start web-group then start mysql-server (kind:Mandatory)
Colocation Constraints:
mysql-server with web-group (score:INFINITY)
Ticket Constraints:

# 查看可用的fencing代理
$ sudo fence_virsh –help

# 配置fencing设备
$ sudo pcs stonith create fence-node1 fence_virsh \
pcmk_host_list=”node1″ \
ipaddr=”192.168.1.1″ \
login=”root” \
passwd=”fgedu123″ \
port=”node1″

$ sudo pcs stonith create fence-node2 fence_virsh \
pcmk_host_list=”node2″ \
ipaddr=”192.168.更多视频教程www.fgedu.net.cn1.1″ \
login=”root” \
passwd=”fgedu123″ \
port=”node2″

$ sudo pcs stonith create fence-node3 fence_virsh \
pcmk_host_list=”node3″ \
ipaddr=”192.168.1.1″ \
login=”root” \
passwd=”fgedu123″ \
port=”node3″

# 查看fencing设备
$ sudo pcs stonith list
fence-node1 (stonith:fence_virsh)
fence-node2 (stonith:fence_virsh)
fence-node3 (stonith:fence_virsh)

# 测试fencing设备
$ sudo pcs stonith test fence-node1 node1
fence-node1: ok

# 案例：企业级Web高可用集群
# 环境：3台服务器
# 目标：实现Web服务的高可用

# 1. 安装Apache
$ sudo dnf install -y httpd

# 2. 创建测试页面
$ sudo echo “Hello from $(hostname)” > /var/www/html/index.html

# 3. 配置集群资源
$ sudo pcs resource create web-vip ocf:heartbeat:IPaddr2 \
ip=192.168.1.200 \
cidr_netmask=24 \
op monitor interval=30s

$ sudo pcs resource create web-service systemd:httpd \
op monitor interval=30s

$ sudo pcs resource group add web-group web-vip web-service

# 4. 测试故障转移
$ sudo pcs cluster stop node1
$ sudo pcs status
Cluster name: fgedu-cluster
Cluster Summary:
* Stack: corosync
* Current DC: node2 (version 2.1.5-9.el9_3.1)
* 3 nodes configured
* 2 resources configured

Online: [ node2 node3 ]
OFFLINE: [ node1 ]

Full list of resources:
Resource Group: web-group
web-vip (ocf::heartbeat:IPaddr2): Started node2
web-service (systemd:httpd): Started node2

# 5. 测试访问
$ curl http://192.168.1.200
Hello from node2

# 案例：MySQL高可用集群
# 环境：3台服务器，1台共享存储
# 目标：实现MySQL数据库的高可用

# 1. 安装MySQL
$ sudo dnf install -y mysql-server

# 2. 配置MySQL
$ sudo systemctl start mysqld
$ sudo mysql_secure_installation

# 3. 创建共享存储
$ sudo pcs resource create mysql-storage ocf:heartbeat:Filesystem \
device=”/dev/vg_shared/lv_mysql” \
directory=”/var/lib/mysql” \
fst学习交流加群风哥QQ113257174ype=”xfs” \
op monitor interval=30s

# 4. 配置MySQL资源
$ sudo pcs resource create mysql-vip ocf:heartbeat:IPaddr2 \
ip=192.168.1.201 \
cidr_netmask=24 \
op monitor interval=30s

$ sudo pcs resource create mysql-service systemd:mysqld \
op monitor interval=30s

# 5. 创建资源组和约束
$ sudo pcs resource group add mysql-group mysql-storage mysql-vip mysql-service

# 6. 测试故障转移
$ sudo pcs cluster stop node1
$ sudo pcs status
Cluster name: fgedu-cluster
Cluster Summary:
* Stack: corosync
* Current DC: node2 (version 2.1.5-9.el9_3.1)
* 3 nodes configured
* 3 resources configured

Online: [ node2 node3 ]
OFFLINE: [ node1 ]

Full list of resources:
Resource Group: mysql-group
mysql-storage (ocf::heartbeat:Filesystem): Started node2
mysql-vip (ocf::heartbeat:IPaddr2): Started node2
mysql-service (systemd:mysqld): Started node2

# 7. 测试MySQL连接
$ mysql -h 192.168.1.201 -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.33 MySQL Community Server – GPL

Copyright (c) 2000, 2023, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the current input statement.

mysql>

# 案例：NFS高可用集群
# 环境：3台服务器，1台共享存储
# 目标：实现NFS服务的高可用

# 1. 安装NFS服务
$ sudo dnf install -y nfs-utils

# 2. 创建共享目录
$ sudo mkdir -p /export/data

# 3. 配置NFS共享
$ sudo echo “/export/data 192.168.1.0/24(rw,sync,no_root_squash)” >> /etc/exports

# 4. 配置集群资源
$ sudo pcs resource create nfs-storage ocf:heartbeat:Filesystem \
device=”/dev/vg_shared/lv_nfs” \
directory=”/export/data” \
fstype=”xfs” \
op monitor interval=30s

$ sudo pcs resource create nfs-vip ocf:heartbeat:IPaddr2 \
ip=192.168.1.202 \
cidr_netmask=24 \
op monitor interval=30s

$ sudo pcs resource create nfs-service systemd:nfs-server \
op monitor interval=30s

# 5. 创建资源组和约束
$ sudo pcs resource group add nfs-group nfs-storage nfs-vip nfs-service

# 6. 测试故障转移
$ sudo pcs cluster stop node1
$ sudo pcs status
Cluster name: fgedu-cluster
Cluster Summary:
* Stack: corosync
* Current DC: node2 (version 2.1.5-9.el9_3.1)
* 3 nodes configured
* 3 resources configured

Online: [ node2 node3 ]
OFFLINE: [ node1 ]

Full list of resources:
Resource Group: nfs-group
nfs-storage (ocf::heartbeat:Filesystem): Started node2
nfs-vip (ocf::heartbeat:IPaddr2): Started node2
nfs-service (systemd:nfs-server): Started node2

# 7. 测试NFS挂载
$ sudo mount -t nfs 192.168.1.202:/export/data /mnt/nfs
$ sudo echo “Hello from NFS” > /mnt/nfs/test.txt
$ cat /mnt/nfs/test.txt
Hello from NFS

# 常见问题与解决方案

## 1. 集群启动失败
– 原因：网络配置错误、防火墙阻止、Corosync配置错误
– 解决方案：检查网络连接、关闭防火墙或开放端口、检查Corosync配置

## 2. 资源启动失败
– 原因：资源配置错误、依赖服务未启动、权限问题
– 解决方案：检查资源配置、确保依赖服务正常运行、检查权限设置

## 3. 故障转移失败
– 原因：fencing配置错误、资源约束冲突、网络问题
– 解决方案：检查fencing配置、调整资源约束、检查网络连接

## 4. 集群脑裂
– 原因：网络分区、节点间通信中断
– 解决方案：配置仲裁机制、使用多网络、设置合适的超时时间

## 5. 性能问题
– 原因：资源配置不当、网络带宽不足、服务器负载过高
– 解决方案：优化资源配置、增加网络带宽、调整服务器资源