---
title: "CentOS7 安装 Mysql Galera 集群"
date: 2019-10-30T11:13:44+08:00
lastmod: 2019-10-30T11:13:44+08:00
keywords: []
tags: ["mysql", "galera"]
categories: ["database"]
---

## 环境
cpu | mem | hostname | public ip | cluster ip | CentOS | MySQL
---- | ---- | ---- | ---- | ---- | ---- | ----
双核 | 2GB | mysql_1 | 10.0.0.231 | 10.10.10.1 | 7.5 | 5.7
双核 | 2GB | mysql_2 | 10.0.0.232 | 10.10.10.2 | 7.5 | 5.7
双核 | 2GB | mysql_3 | 10.0.0.233 | 10.10.10.3 | 7.5 | 5.7

## 创建 galera yum 源文件
```bash
cat > /etc/yum.repos.d/galera.repo <<-END
[galera]
name = Galera
baseurl = http://releases.galeracluster.com/galera-3/centos/7/x86_64/
gpgkey = http://releases.galeracluster.com/GPG-KEY-galeracluster.com
gpgcheck = 1

[mysql-wsrep]
name = MySQL-wsrep
baseurl = http://releases.galeracluster.com/mysql-wsrep-5.7/centos/7/x86_64/
gpgkey = http://releases.galeracluster.com/GPG-KEY-galeracluster.com
gpgcheck = 1
END
```

## 安装
```bash
yum install galera-3 mysql-wsrep-5.7 rsync
```

## 修改 /etc/my.cnf
```
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
binlog-format=ROW
bind-address=0.0.0.0
default-storage-engine=innodb
innodb-autoinc-lock-mode=2
innodb-flush-log-at-trx-commit=0
innodb-buffer-pool-size=1024M #物理内存一半
wsrep-provider=/usr/lib64/galera-3/libgalera_smm.so
wsrep-provider-options="gcache.dir=/var/lib/gcache;gcache.size=1G;gcache.recover=yes;pc.recovery=TRUE"
wsrep-cluster-name="mysql_galera_cluster" #集群名字
wsrep-cluster-address="gcomm://10.10.10.1,10.10.10.2,10.10.10.3"
wsrep-sst-method=rsync
wsrep-node-name=mysql_1 #当前节点名字
wsrep-node-address="10.10.10.1" #当前节点 cluster ip
#wsrep-auto-increment-control=OFF #只通过一个节点做增删改时使用

[mysql_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

!includedir /etc/my.cnf.d/
```

## 随机选择一个节点，使用专用脚本 mysqld_bootstrap 初始化集群
```bash
/usr/bin/mysqld_bootstrap
# 该命令会启动本机的 mysqld 服务
systemctl status mysqld
```

## 查找密码，修改初始密码
```bash
grep -i password /var/log/messages
# 记录输出的密码
mysqladmin -uroot -p password 'P@sswo2d'
# 根据提示输入上一步输出的密码
```

## 在其他节点上启动 mysqld 服务
```bash
systemctl start mysqld
```

## 查看集群节点数量
```sql
show status like 'wsrep_cluster_size';
```

## ssl 加密同步数据(不推荐，存在性能损失)
- 生成证书
    ```bash
    mkdir /etc/my.cnf.d/ssl && cd /etc/my.cnf.d/ssl
    openssl genrsa 2048 > ca-key.pem
    openssl req -new -x509 -nodes -days 365000 \
          -key ca-key.pem -out ca-cert.pem #按提示输入信息
    openssl req -newkey rsa:2048 -days 365000 \
          -nodes -keyout server-key.pem -out server-req.pem #按提示输入信息，与上一步信息不同
    openssl rsa -in server-key.pem -out server-key.pem
    openssl x509 -req -in server-req.pem -days 365000 \
          -CA ca-cert.pem -CAkey ca-key.pem -set_serial 01 \
          -out server-cert.pem
    ```

- 修改配置文件 my.cnf
    ```
    # 在 wsrep_provider_options 中添加如下选项，选项间用分号";"间隔
    socket.ssl_key=/etc/my.cnf.d/ssl/server-key.pem; socket.ssl_cert=/etc/my.cnf.d/ssl/server-cert.pem; socket.ssl_ca=/etc/my.cnf.d/ssl/ca-cert.pem; socket.checksum=2; socket.ssl_cipher=AES128-SHA
    ```

- 重新启动集群

## ssl 加密客户端(不推荐，存在性能损失)
- MySQL 5.7 server 自带 ssl 加密，客户端连接时，指定参数 --ssl-mode=required 即可