DBA面对新mysql环境

来源：http://blog.csdn.net/wyzxg/article/details/8491152

author：skate
time：2013/01/10

DBA面对新MySQL环境感悟

1.初识单个mysql服务器
2.初识生产环境mysql架构
3.初识cache层和mysql的关系
4.初识其他API(如消息队列)和mysql的关系
5.初识业务和mysql的关系

1.初识单个mysql服务器

1.1 一个全新的Mysql环境，要基本了解mysql版本、os平台、字符集等信息
mysql> status;
--------------
mysql  Ver 14.12 Distrib 5.0.95, for redhat-Linux-gnu (x86_64) using readline 5.1

Connection id:          25
Current database:       skate
Current user:           root@localhost
SSL:                    Not in use
Current pager:          stdout
Using outfile:          ''
Using delimiter:        ;
Server version:         5.5.24-log Source distribution
Protocol version:       10
Connection:             Localhost via UNIX socket
Server characterset:    latin1
Db     characterset:    latin1
Client characterset:    latin1
Conn.  characterset:    latin1
UNIX socket:            /tmp/mysql.sock
Uptime:                 12 days 13 min 7 sec

Threads: 3  Questions: 2100307  Slow queries: 0  Opens: 47  Flush tables: 1  Open tables: 39  Queries per second avg: 2.024
--------------

mysql>

1.2 了解mysql支持哪些存储引擎
mysql> show engines;
+--------------------+---------+----------------------------------------------------------------------------+--------------+------+------------+
| Engine             | Support | Comment                                                                    | Transactions | XA   | Savepoints |
+--------------------+---------+----------------------------------------------------------------------------+--------------+------+------------+
| InnoDB             | DEFAULT | Percona-XtraDB, Supports transactions, row-level locking, and foreign keys | YES          | YES  | YES        |
| PERFORMANCE_SCHEMA | YES     | Performance Schema                                                         | NO           | NO   | NO         |
| MyISAM             | YES     | MyISAM storage engine                                                      | NO           | NO   | NO         |
| CSV                | YES     | CSV storage engine                                                         | NO           | NO   | NO         |
| 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         |
+--------------------+---------+----------------------------------------------------------------------------+--------------+------+------------+
6 rows in set (0.00 sec)

mysql>

1.3 了解mysql安装了哪些插件
mysql> show plugins;
+--------------------------------+--------+--------------------+--------------------+---------+
| Name                           | Status | Type               | Library            | License |
+--------------------------------+--------+--------------------+--------------------+---------+
| binlog                         | ACTIVE | STORAGE ENGINE     | NULL               | GPL     |
| mysql_native_password          | ACTIVE | AUTHENTICATION     | NULL               | GPL     |
| mysql_old_password             | ACTIVE | AUTHENTICATION     | NULL               | GPL     |
| MEMORY                         | ACTIVE | STORAGE ENGINE     | NULL               | GPL     |
| MyISAM                         | ACTIVE | STORAGE ENGINE     | NULL               | GPL     |
| CSV                            | ACTIVE | STORAGE ENGINE     | NULL               | GPL     |
| MRG_MYISAM                     | ACTIVE | STORAGE ENGINE     | NULL               | GPL     |
| InnoDB                         | ACTIVE | STORAGE ENGINE     | NULL               | GPL     |
......
......
| PERFORMANCE_SCHEMA             | ACTIVE | STORAGE ENGINE     | NULL               | GPL     |
| partition                      | ACTIVE | STORAGE ENGINE     | NULL               | GPL     |
| rpl_semi_sync_slave            | ACTIVE | REPLICATION        | semisync_slave.so  | GPL     |
| rpl_semi_sync_master           | ACTIVE | REPLICATION        | semisync_master.so | GPL     |
+--------------------------------+--------+--------------------+--------------------+---------+
34 rows in set (0.00 sec)

mysql>

1.4 了解mysql是单机还是ndb集群
mysql> show variables like 'have_ndbcluster';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| have_ndbcluster | NO    | 
+-----------------+-------+
1 row in set (0.00 sec)

mysql>

1.5 了解是否配置REPLICATION
mysql> show slave status\G;
mysql> show master status\G;

1.6 查看Mysql的日志模式
mysql> show variables like 'log%';
+---------------------------------+------------------------------------------------+
| Variable_name                   | Value                                          |
+---------------------------------+------------------------------------------------+
| log                             | OFF                                            |
| log_bin                         | ON                                             |
| log_bin_trust_function_creators | OFF                                            |
| log_error                       | /data/mysql/usr/local/mysql/data/localhost.err |
| log_output                      | FILE                                           |
| log_queries_not_using_indexes   | OFF                                            |
| log_slave_updates               | OFF                                            |
| log_slow_admin_statements       | OFF                                            |
| log_slow_filter                 |                                                |
| log_slow_queries                | OFF                                            |
| log_slow_rate_limit             | 1                                              |
| log_slow_rate_type              | session                                        |
| log_slow_slave_statements       | OFF                                            |
| log_slow_sp_statements          | ON                                             |
| log_slow_verbosity              |                                                |
| log_warnings                    | 1                                              |
| log_warnings_suppress           |                                                |
+---------------------------------+------------------------------------------------+
17 rows in set (0.00 sec)

mysql>

1.7 查看Mysql当前有哪些触发器和存储过程
mysql> show triggers;
mysql> show procedure status;

mysql> select TABLE_NAME from information_schema.PARTITIONS where PARTITION_NAME is not null;

1.8 有多少用户拥有超级权限,是否有密码为空（ROOT密码默认为空），密码为空马上处理
mysql> select * from information_schema.USER_PRIVILEGES where PRIVILEGE_TYPE='SUPER';
+--------------------+---------------+----------------+--------------+
| GRANTEE            | TABLE_CATALOG | PRIVILEGE_TYPE | IS_GRANTABLE |
+--------------------+---------------+----------------+--------------+
| 'root'@'localhost' | def           | SUPER          | YES          |
| 'root'@'127.0.0.1' | def           | SUPER          | YES          |
| 'root'@'::1'       | def           | SUPER          | YES          |
| 'rep'@'%'          | def           | SUPER          | NO           |
| 'root'@'%'         | def           | SUPER          | NO           |
| 'skate'@'%'        | def           | SUPER          | NO           |
+--------------------+---------------+----------------+--------------+
6 rows in set (0.02 sec)

mysql> select host,user,password from mysql.user where password='';
+-----------+------+----------+
| host      | user | password |
+-----------+------+----------+
| 127.0.0.1 | root |          | 
| ::1       | root |          | 
| localhost |      |          | 
+-----------+------+----------+
3 rows in set (0.00 sec)

mysql>

1.9 查看数据的存放目录
mysql> show variables like '%datadir%';
+---------------+-----------------------------------+
| Variable_name | Value                             |
+---------------+-----------------------------------+
| datadir       | /data/mysql/usr/local/mysql/data/ | 
+---------------+-----------------------------------+
1 row in set (0.00 sec)

mysql>

1.10 查看重要的内存参数
innodb_buffer_pool_size 
innodb_log_file_size
innodb_log_buffer_size
innodb_log_files_in_group
max_connections
innodb_flush_log_trx_commit
innodb_max_dirty_pages_pct
innodb_flush_method
sync-binlog

1.11 执行一会show processlist，看看Mysql能有多少并发，一般都是什么sql。
1.12 更进一步,Mysql的备份方法和策略是什么？网络环境的配置是如何的？
1.13 跑几个性能分析报告，看看最近系统的运行状态如何，例如用mysqlreport。

os相关信息：

1.14 查看机器型号
# dmidecode |grep "Product Name"

1.15 查看cpu型号，及逻辑cpu数量
# cat /proc/cpuinfo |grep name| cut -f2 -d: |uniq -c

1.16 查看内存大小，存储大小
free，df

相关命令：
mysql> status;
mysql> show engines;
mysql> show plugins;
mysql> show variables like 'have_ndbcluster';
mysql> show slave status\G;
mysql> show master status\G;
mysql> show triggers;
mysql> show procedure status;
mysql> select * from information_schema.USER_PRIVILEGES where PRIVILEGE_TYPE='SUPER';
mysql> select host,user,password from mysql.user where password='';
mysql> show variables like '%datadir%';
mysql> show processlist

# dmidecode |grep "Product Name"
# cat /proc/cpuinfo |grep name| cut -f2 -d: |uniq -c

2.初识生产环境mysql架构

mysql单机环境通过个人就可以大概了解数据库的基本信息，如果数据库环境比较复杂，如下相关问题就要咨询相关同学，如果有
文档最好。

数据库如何横向、纵向的拆分
每个集群的容灾方式如何
是否有故障隔离
是否有优雅降级
数据库层是如何自我保护的
监控框架如何
备份框架如何
安全体系如何

3.初识cache层和mysql的关系

cache主要用于承载数据库存储层的大部分io，那我们就要对cache有一定的了解

那cache层和数据库存储层是什么关系？是应用来保证cache层数据库新鲜？还是数据库主动更新cache层数据？
cache层是用什么软件实现的？
cache层失效之后的数据预热是否对数据库存储层有冲击

4.初识其他API(如消息队列)和mysql的关系

不同的mysql之间(或mysql和其他组件之间)可能需要数据同步传输，这些依赖关系我们要了解。mysql之间的同步是通过什么技术？

5.初识业务和mysql的关系
数据库的存在的意义就是为不同的业务提供服务，所以要更好的了解数据库，就要了解业务和不同数据库的关系，从下到上，再从上到下，这样才能更好的做好数据库管理工作。