面对一个全新的环境,作为一个Mysql DBA,首先应该了解什么?

2009年07月08日　作者： 大头刚　

强烈支持下此文

前段时间有高人写了一篇《面对一个全新的环境,作为一个Oracle DBA,首先应该了解什么》，本文借花献佛，总结了一些思路，如何面对一个全新的Mysql环境。

1、先要了解当前的Mysql数据库的版本和平台以及字符集等相关信息

mysql> status
 
--------------
mysql  Ver 14.14 Distrib 5.1.34, for unknown-linux-gnu (x86_64) using  EditLine wrapper
Connection id:                25874330
Current database:       
Current user:               
SSL:                        Not in use
Current pager:                stdout
Using outfile:                ''
Using delimiter:        ;
Server version:                5.1.34-log Source distribution
Protocol version:        10
Connection:                Localhost via UNIX socket
Server characterset:        utf8
Db     characterset:        utf8
Client characterset:        utf8
Conn.  characterset:        utf8
UNIX socket:                /tmp/mysql.sock
Uptime:                        13 days 14 hours 18 min 36 sec
Threads: 7  Questions: 190708290  Slow queries: 19  Opens: 57835  Flush tables: 1 
Open tables: 84  Queries per second avg: 162.344
--------------

2、其次要了解你的数据库中支持哪些存储引擎，5.1的话顺便查下插件情况。

mysql> show engines;
 
+------------+---------+----------------------------------------------------------------+--------------+------+------------+
| Engine     | Support | Comment                                                        | Transactions | XA   | Savepoints |
+------------+---------+----------------------------------------------------------------+--------------+------+------------+
| InnoDB     | YES     | Supports transactions, row-level locking, and foreign keys     | YES          | YES  | YES        |
| MRG_MYISAM | YES     | Collection of identical MyISAM tables                          | NO           | NO   | NO         |
| BLACKHOLE  | YES     | /dev/null storage engine (anything you write to it disappears) | NO           | NO   | NO         |
| CSV        | YES     | CSV storage engine                                             | NO           | NO   | NO         |
| MEMORY     | YES     | Hash based, stored in memory, useful for temporary tables      | NO           | NO   | NO         |
| FEDERATED  | NO      | Federated MySQL storage engine                                 | NULL         | NULL | NULL       |
| ARCHIVE    | YES     | Archive storage engine                                         | NO           | NO   | NO         |
| MyISAM     | DEFAULT | Default engine as of MySQL 3.23 with great performance         | NO           | NO   | NO         |
+------------+---------+----------------------------------------------------------------+--------------+------+------------+
8 rows in set (0.00 sec)
 
mysql> show plugins;
 
+------------+----------+----------------+---------+---------+
| Name       | Status   | Type           | Library | License |
+------------+----------+----------------+---------+---------+
| binlog     | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| partition  | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| ARCHIVE    | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| BLACKHOLE  | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| CSV        | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| FEDERATED  | DISABLED | STORAGE ENGINE | NULL    | GPL     |
| MEMORY     | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| InnoDB     | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| MyISAM     | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| MRG_MYISAM | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
+------------+----------+----------------+---------+---------+

3、搞清楚这个环境是单机还是集群？

mysql> show variables like 'have_ndbcluster';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| have_ndbcluster | NO    |
+-----------------+-------+
1 row in set (0.00 sec)

4、是否配置了REPLICATION？

show slave status\G;
show master status\G;

5、查看Mysql的日志模式，查看近期的慢查询日志和ERR日志。

mysql> show variables like 'log%';
+---------------------------------+----------------------+
| Variable_name                   | Value                |
+---------------------------------+----------------------+
| log                             | OFF                  |
| log_bin                         | ON                   |
| log_bin_trust_function_creators | OFF                  |
| log_bin_trust_routine_creators  | OFF                  |
| log_error                       | /dir/hostname.err    |
| log_output                      | FILE                 |
| log_queries_not_using_indexes   | OFF                  |
| log_slave_updates               | OFF                  |
| log_slow_queries                | ON                   |
| log_warnings                    | 1                    |
+---------------------------------+----------------------+

　
6、查看Mysql当前有哪些触发器和存储过程

mysql> show triggers;
mysql> show procedure status;

7、是否支持分区，如果支持哪些使用了分区表

mysql> show variables like 'have_part%';
+-------------------+-------+
| Variable_name     | Value |
+-------------------+-------+
| have_partitioning | YES   |
+-------------------+-------+
1 row in set (0.00 sec)
 
mysql> select TABLE_NAME from information_schema.PARTITIONS where PARTITION_NAME is not null;

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';
mysql> select host,User,Password from mysql.user where Password='';
+-------------+------+----------+
| host        | User | Password |
+-------------+------+----------+
| localhost   | root |          |
| 127.0.0.1   | root |          |
+-------------+------+----------+
mysql> delete from mysql.user where Password='';flush PRIVILEGES;

9.show processlist
执行一会show processlist，看看 Mysql 能有多少并发，一般都是什么sql。

 

10、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？

 

11、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。

 

OK，以上信息基本上对你新接触的这个系统有了一个大概的了解，接下来你再慢慢的深入分析，然后制订出一套符合实际情况的运维规范来。

 

当然，这只是个人的一些心得和体会,每个人的认识的角度是不一样的，欢迎大家继续补充完善。