数据库_PXC群集与存储引擎

1. PXC介绍与群集搭建; 2.数据存储引擎.

一, PXC介绍

1.介绍

PXC(Percona XtraDB Cluster)基于Galara的一台开源软件,应用于解决mysql的高可用集群问题,由Codership公司开发,PXC群集主要由于两部分组成:Percona Server with XtraDB和Write Set Replication patches(同步,多主复制插件).

2.特点:数据高度一致性,没有同步延迟问题;没有主从切换操作,且无需使用虚拟IP;支持InnoDB存储引擎;多线程复制;部署使用简单;支持节点自动加入,无需手动拷贝数据.

3.服务端口:

- 3306 数据库服务端口

- 4444 SST端口

- 4567 集群成员通信端口

- 4568 IST端口

- SST state snapshot transfer 全量同步

- IST incremental state transfer 增量同步

二,搭建PXC集群

1.部署环境

#vim /etc/hosts //使用本机解析主机名

192.168.4.71 pxcnode71

192.168.4.72 pxcnode72

192.168.4.73 pxcnode73

[student@room9pc01 package]$ for i in 71 72 73 //传输软件包到对应虚拟主机

> do

> scp /home/student/bin/package/PXC.tar.gz root@192.168.4.$i:/root/

> done

PXC.tar.gz 100% 196MB 98.0MB/s 00:02

PXC.tar.gz 100% 196MB 147.3MB/s 00:01

PXC.tar.gz 100% 196MB 173.9MB/s 00:01

2.部署PXC

2.1 安装软件

#rpm -ivh libev-4.15-1.el6.rf.x86_64.rpm

#yum -y install percona-xtrabackup-24-2.4.13-1.el7.x86_64.rpm

#rpm -ivh qpress-1.1-14.11.x86_64.rpm

#tar -xvf Percona-XtraDB-Cluster-5.7.25-31.35-r463-el7-x86_64-bundle.tar

#yum -y install percona-release-0.1-4.noarch.rpm

2.2 查看配置文件

# ls /etc/percona-xtradb-cluster.conf.d //配置文件的目录

mysqld.cnf mysqld_safe.cnf wsrep.cnf

- 说明: mysqld.cnf ---数据库服务运行参数配置文件; mysqld_safe.cnf ---Percona Server5.7配置文件; wsrep.cnf ---PXC集群配置文件

2.3 修改数据库服务运行参数配置文件

71]# vim /etc/percona-xtradb-cluster.conf.d/mysqld.cnf

[mysqld]

server-id=71 //改动id为71

datadir=/var/lib/mysql

socket=/var/lib/mysql/mysql.sock

log-error=/var/log/mysqld.log

pid-file=/var/run/mysqld/mysqld.pid

log-bin

log_slave_updates

expire_logs_days=7

72]# vim /etc/percona-xtradb-cluster.conf.d/mysqld.cnf

[mysqld]

server-id=72 //改动id为72

datadir=/var/lib/mysql

socket=/var/lib/mysql/mysql.sock

log-error=/var/log/mysqld.log

pid-file=/var/run/mysqld/mysqld.pid

log-bin

log_slave_updates

expire_logs_days=7

73]# vim /etc/percona-xtradb-cluster.conf.d/mysqld.cnf

[mysqld]

server-id=73 //改动id为73

datadir=/var/lib/mysql

socket=/var/lib/mysql/mysql.sock

log-error=/var/log/mysqld.log

pid-file=/var/run/mysqld/mysqld.pid

log-bin

log_slave_updates

expire_logs_days=7

2.4 查看Percona Server5.7配置文件

71]# cat /etc/percona-xtradb-cluster.conf.d/mysqld_safe.cnf

72]# cat /etc/percona-xtradb-cluster.conf.d/mysqld_safe.cnf

73]# cat /etc/percona-xtradb-cluster.conf.d/mysqld_safe.cnf

2.5 需改PXC集群配置文件

71]vim /etc/percona-xtradb-cluster.conf.d/wsrep.cnf

wsrep_cluster_address=gcomm://192.168.4.71,192.168.4.72,192.168.4.73 //集群成员列表

wsrep_node_address=192.168.4.71 //本机ip地址

wsrep_cluster_name=pxc-cluster //集群名称,3台机器必须一致

wsrep_node_name=pxcnode71 //本机的hostname

wsrep_sst_auth="sstuser:123456" //sst数据同步授权用户

72]vim /etc/percona-xtradb-cluster.conf.d/wsrep.cnf

wsrep_cluster_address=gcomm://192.168.4.71,192.168.4.72,192.168.4.73

wsrep_node_address=192.168.4.72

wsrep_cluster_name=pxc-cluster

wsrep_node_name=pxcnode72

wsrep_sst_auth="sstuser:123456"

73]vim /etc/percona-xtradb-cluster.conf.d/wsrep.cnf

wsrep_cluster_address=gcomm://192.168.4.71,192.168.4.72,192.168.4.73

wsrep_node_address=192.168.4.73

wsrep_cluster_name=pxc-cluster

wsrep_node_name=pxcnode73

wsrep_sst_auth="sstuser:123456"

2.6 启动服务,添加授权用户

注意,只在一台机器上启动服务即可,当前以在192.168.4.71上启动服务为例

71]# systemctl start mysql@bootstrap.service //启动PXC服务

[root@pxcnode71 PXC]# grep 'pass' /var/log/mysqld.log

2019-06-21T03:48:41.965682Z 1 [Note] A temporary password is generated for root@localhost: aBZIAuvq<1Ti //查看mysql的初始密码

# mysql -uroot -p'aBZIAuvq<1Ti' //使用初始密码登录

mysql> alter user root@"localhost" identified by '123456'; //更改密码

mysql> grant reload,lock tables,replication client,process on *.* to sstuser@"localhost" identified by '123456'; //授权用户sstuser

2.7 在4.72和4.73的主机上启动mysql服务

72]# systemctl start mysql

73]# systemctl start mysql

2.8 查看集群信息

71]mysql -uroot -p123456 -e 'show status like "%wsrep%"'

72]mysql -uroot -p123456 -e 'show status like "%wsrep%"'

73]mysql -uroot -p123456 -e 'show status like "%wsrep%"'

wsrep_incoming_addresses | 192.168.4.72:3306,192.168.4.73:3306,192.168.4.71:3306

wsrep_cluster_size | 3

wsrep_cluster_status | Primary

wsrep_connected | ONwsrep_ready | ON

3.0 测试集群功能

3.1 在主机4.71上授权,自动同步授权到4.72和4.73.

71]grant all on gamedb.* to yaya@"%" identified by '123456';

3.2 客户端4.50登录到服务器4.72

# mysql -h192.168.4.72 -uyaya -p123456

mysql> create database gamedb; //建库

mysql> create table gamedb.a( //建表

-> id int primary key auto_increment,name char(10));

mysql> insert into gamedb.a values(1,"tom"); //插入数据

mysql> insert into gamedb.a values(2,"jack"); //插入数据

3.3 分别在4.71,4.72,4.73上查看插入的数据

mysql> select * from gamedb.a;

+----+------+

| id | name |

+----+------+

| 1 | tom |

| 2 | jack |

+----+------+

2 rows in set (0.00 sec)

4.0 测试服务器故障,再自动恢复

71]# systemctl stop mysql //停止4.71的服务

mysql> insert into gamedb.a values(3,"tom1"); //客户端写入数据

Query OK, 1 row affected (0.16 sec)

mysql> insert into gamedb.a values(4,"jack1"); //客户端写入数据

Query OK, 1 row affected (0.12 sec)

mysql> select * from gamedb.a; //在服务器4.72和4.71查看插入的数据

+----+-------+

| id | name |

+----+-------+

| 1 | tom |

| 2 | jack |

| 3 | tom1 |

| 4 | jack1 |

+----+-------+

4 rows in set (0.00 sec)

71]# ]# systemctl start mysql@bootstrap.service //再次启动4.71的集群服务

71]# netstat -anptul|grep :3306 //查看mysql端口

71]# netstat -anptul|grep :4567 //查看集群端口

mysql> select * from gamedb.a; //查看4.71的数据同步状态

+----+-------+

| id | name |

+----+-------+

| 1 | tom |

| 2 | jack |

| 3 | tom1 |

| 4 | jack1 |

+----+-------+

4 rows in set (0.00 sec)

三,Mysql存储引擎

1.存储引擎?

作为可插拔式的组件提供,mysql自带的功能程序,专属于表的处理器;不同的存储引擎有不同的动能和存储方式.

2.查看数据库服务器可以使用的存储引擎

mysql> show engines;

+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+

+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+

| InnoDB | DEFAULT | Supports transactions, row-level locking, and foreign keys | YES | YES | YES |

| MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO |

| MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO |

| BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO |

| MyISAM | YES | MyISAM storage engine | NO | NO | NO |

| CSV | YES | CSV storage engine | NO | NO | NO |

| ARCHIVE | YES | Archive storage engine | NO | NO | NO |

| PERFORMANCE_SCHEMA | YES | Performance Schema | NO | NO | NO |

+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+

9 rows in set (0.01 sec)

3.建表时,手动指定存储引擎

mysql> create database db10;

mysql> create table db10.t1(

-> id int,name char(10))engine=myisam; //建表时指定存储引擎为myisam

Query OK, 0 rows affected (0.05 sec)

mysql> show create table t1 \G; //查看存储引擎

*************************** 1. row ***************************

Table: t1

Create Table: CREATE TABLE `t1` (

`id` int(11) DEFAULT NULL,

`name` char(10) DEFAULT NULL

) ENGINE=MyISAM DEFAULT CHARSET=latin1 //显示存储引擎

1 row in set (0.01 sec)

4.在数据库服务的主配置文件中修改存储引擎

#vim /etc/my.cnf

[mysqld]

default-storage-engine=myisam //指定存储引擎

# systemctl restart mysqld //重启加载配置

5.对已建表的引擎做修改

Mysql>alter table 库名.表名 engine=引擎类型;

Mysql>alter table db10.t1 engine=myisam;

6.常用存储引擎的特点

Myisam存储引擎: 不支持表级锁;不支持事务,事务回滚,外键.

Myisam的表文件: 表结构-表名.frm; 索引-表名.MYI; 数据-表名.MYD

Innodb存储引擎:支持行级锁定,支持事务,事务回滚,外键.

Innodb的表文件:表名.frm和表名.idb.

Innodb的日志文件:ibdata1,ib_logfile0,ib_logfile1

7.Mysql的锁机制

7.1 锁的力度:表级锁(整张表)与行级锁(单行)

7.2 锁的类型:a.读锁(共享锁),支持并发性读b.写锁,独立的锁,上锁期间其它线程不能读和写.

7.3 查看当前锁的状态

[root@client ~]# mysql -uroot -p123456 -e 'show status like "%table_lock%"'

+-----------------------------------------+-------+

| Variable_name | Value |

+-----------------------------------------+-------+

| Performance_schema_table_lock_stat_lost | 0 |

| Table_locks_immediate | 88 |

| Table_locks_waited | 0 |

+-----------------------------------------+-------+

8.事务的特性

Atomic原子性,事务的操作是一个整体,不可分割,要么全部成功,要么全部失败.

Consitency一致性,事务操作的前后,表中的记录没有变化.

Isolation隔离性,事务之间的操作是隔离不受彼此影响的.

Durability永久性,数据一旦提交即不可更改.

测试永久性: 开两个相同的终端4.50,在其中一个终端上做如下操作.

mysql> show variables like "autocommit";

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| autocommit | ON |

+---------------+-------+

1 row in set (0.00 sec)

mysql> set autocommit=off; //关闭自动提交功能

mysql> show variables like "autocommit";

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| autocommit | OFF |

+---------------+-------+

1 row in set (0.00 sec)

mysql> create table db10.a4(

-> id int )engine=innodb;

Query OK, 0 rows affected (0.37 sec)

mysql> insert into db10.a4 values(200);

mysql> insert into db10.a4 values(300);

mysql> select * from db10.a4; //在关闭了commit的终端可以查看到插入的数据,而另一终端却不能查看到提交的数据.

+------+

| id |

+------+

| 200 |

| 300 |

+------+

2 rows in set (0.00 sec)

mysql> commit; //执行commit后,在没有关闭commit的终端可以查看到插入的数据.

总结: 那么我们在生产环境中,建表时如何决定使用存储引擎的类型,有以下两个意见:

- 查询操作相对较多的表,适合使用myisam引擎,以节省系统资源

- 写操作相对较多的表,适合使用innodb引擎,以解决并发性访问量大的问题

结束.