3. 安装MySQL-pxc

3.1. 说明

之前为了搭建高可用的MySQL的集群，所以安装MySQL-pxc，具体介绍可以看https://www.percona.com/software/mysql-database/percona-xtradb-cluster
不知道为什么服务器下载都巨慢，所以我都使用离线安装。下载的是主要的包，还有其他一堆依赖需要服务器自己去下载。

ansiblehosts文件

[mysqlservers]
sz-1 node_name=pxc1
sz-2 node_name=pxc2

3.2. yml脚本

---
- hosts: mysqlservers
  remote_user: root
  vars_files:
    - ../vars.yml

  tasks:
  - name: Ensure SELinux is set to enforcing mode
    lineinfile:
      path: /etc/selinux/config
      regexp: '^SELINUX='
      line: SELINUX=permissive
  - name: Copy rpm
    copy:
      src: "{{ PLAYBOOK_DIR }}/files/mysql"
      dest: /mnt
      owner: root
      group: root
      mode: 0755
  - name: install prepare
    yum:
      name: "/mnt/mysql/percona-release-latest.noarch.rpm"
      state: present

  - name: install pxc
    shell: "yum localinstall -y /mnt/mysql/Percona/*"

  - name: firewarld add 3306
    firewalld:
      port: 3306/tcp
      permanent: true
      immediate: true
      zone: public
      state: enabled
  - name: firewarld add 4444
    firewalld:
      port: 4444/tcp
      permanent: true
      immediate: true
      zone: public
      state: enabled
  - name: firewarld add 4567
    firewalld:
      port: 4567/tcp
      permanent: true
      immediate: true
      zone: public
      state: enabled
  - name: firewarld add 4568
    firewalld:
      port: 4568/tcp
      permanent: true
      immediate: true
      zone: public
      state: enabled
      
  - name: Copy config
    template:
      src: "{{ PLAYBOOK_DIR }}/mysql-pxc/templates/wsrep.cnf.j2"
      dest: /etc/percona-xtradb-cluster.conf.d/wsrep.cnf
      owner: root
      group: root
      mode: 0755

  - name: set SELinux to permissive
    shell: setenforce 0
    
  - name: start mysql@bootstrap
    service:
      name: mysql@bootstrap
      state: started
    when: inventory_hostname == groups['mysqlservers'][0]

3.3. 模板文件

因为搭建的是集群环境，因此都需要配置节点

3.3.1 wsrep.cnf.j2

[mysqld]
# Path to Galera library
wsrep_provider=/usr/lib64/galera3/libgalera_smm.so

# Cluster connection URL contains IPs of nodes
#If no IP is found, this implies that a new cluster needs to be created,
#in order to do that you need to bootstrap this node
wsrep_cluster_address=gcomm://{% set comma = joiner(",") %}
{% for item in groups['mysqlservers'] -%}
    {{ comma() }}{{ hostvars[item].inventory_hostname }}
{%- endfor %}

# In order for Galera to work correctly binlog format should be ROW
binlog_format=ROW

# MyISAM storage engine has only experimental support
default_storage_engine=InnoDB

# Slave thread to use
wsrep_slave_threads=8

wsrep_log_conflicts

# This changes how InnoDB autoincrement locks are managed and is a requirement for Galera
innodb_autoinc_lock_mode=2

# Node IP address
wsrep_node_address={{ ansible_default_ipv4.address }}
# Cluster name
wsrep_cluster_name=newtranx-pxc-cluster

#If wsrep_node_name is not specified,  then system hostname will be used
wsrep_node_name={{ node_name }}

#pxc_strict_mode allowed values: DISABLED,PERMISSIVE,ENFORCING,MASTER
pxc_strict_mode=ENFORCING

# SST method
wsrep_sst_method=xtrabackup-v2

#Authentication for SST method
wsrep_sst_auth=sstuser:passw0rd

3.4. 运行ansible-playbook

ansible-playbook -i /etc/ansible/hosts mysql/main.yml

3.5. 基本配置

修改密码、创建远程用户、修改权限，这里不做赘述，参考之前写的《Ansible部署系列：（六）安装MySQL》

3.6. 启动其他节点

---
- hosts: mysqlservers
  remote_user: root
  vars_files:
    - ../vars.yml

  tasks:
    - name: set SELinux to permissive
      shell: setenforce 0
  
    - name: start mysql
      service:
        name: mysqld
        state: started
      when: inventory_hostname != groups['mysqlservers'][0]

3.7. 查看各节点状态

show status like 'wsrep%';