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生产环境MySQL表的维护,优化Mysql数据表的shell脚

2019-11-14 23:33栏目:联系我们
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MySQL表碎片整理

  • 1. 计算碎片大小
  • 2. 整理碎片
    • 2.1 使用alter table table_name engine = innodb命令进行整理。
    • 2.2 使用pt-online-schema-change工具也能进行在线整理表结构,收集碎片等操作。
    • 2.3 使用optimize table命令,整理碎片。
  • 3. 整理表碎片shell脚本

由于公司数据库中的数据量较大,定期对公司的mysql数据库中的数据表进行优化操作(关于optimize的描述如下所示),数据库中有300多张数据表,手工去操作显然不太现实,用脚本来执行效率还是很不错的,脚本如下:

生产环境MySQL表的维护:check、optimize和analyze

这里在Linux下使用到crontab定时任务的添加及mysqldump执行简单的数据库备份,具体步骤如下:

1. 计算碎片大小

要整理碎片,首先要了解碎片的计算方法。

可以通过show table [from|in db_name] status like '%table_name%'命令查看:

mysql> show table from employees status like 't1'G
*************************** 1. row ***************************
           Name: t1
         Engine: InnoDB
        Version: 10
     Row_format: Dynamic
           Rows: 1176484
 Avg_row_length: 86
    Data_length: 101842944
Max_data_length: 0
   Index_length: 0
      Data_free: 39845888
 Auto_increment: NULL
    Create_time: 2018-08-28 13:40:19
    Update_time: 2018-08-28 13:50:43
     Check_time: NULL
      Collation: utf8mb4_general_ci
       Checksum: NULL
 Create_options: 
        Comment: 
1 row in set (0.00 sec)

 

碎片大小 = 数据总大小 - 实际表空间文件大小

  • 数据总大小 = Data_length Data_length = 101842944

  • 实际表空间文件大小 = rows * Avg_row_length = 1176484 * 86 = 101177624

  • 碎片大小 = (101842944 - 101177624) / 1024 /1024 = 0.63MB

通过information_schema.tablesDATA_FREE列查看表有没有碎片:

SELECT t.TABLE_SCHEMA,
       t.TABLE_NAME,
       t.TABLE_ROWS,
       t.DATA_LENGTH,
       t.INDEX_LENGTH,
       concat(round(t.DATA_FREE / 1024 / 1024, 2), 'M') AS datafree
FROM information_schema.tables t
WHERE t.TABLE_SCHEMA = 'employees'


 -------------- -------------- ------------ ------------- -------------- ---------- 
| TABLE_SCHEMA | TABLE_NAME   | TABLE_ROWS | DATA_LENGTH | INDEX_LENGTH | datafree |
 -------------- -------------- ------------ ------------- -------------- ---------- 
| employees    | departments  |          9 |       16384 |        16384 | 0.00M    |
| employees    | dept_emp     |     331143 |    12075008 |     11567104 | 0.00M    |
| employees    | dept_manager |         24 |       16384 |        32768 | 0.00M    |
| employees    | employees    |     299335 |    15220736 |            0 | 0.00M    |
| employees    | salaries     |    2838426 |   100270080 |     36241408 | 5.00M    |
| employees    | t1           |    1191784 |    48824320 |     17317888 | 5.00M    |
| employees    | titles       |     442902 |    20512768 |     11059200 | 0.00M    |
| employees    | ttt          |          2 |       16384 |            0 | 0.00M    |
 -------------- -------------- ------------ ------------- -------------- ---------- 
8 rows in set (0.00 sec)

 

mysql手册中关于 OPTIMIZE 的描述:

 

1.      编写一个脚本: /serverBack/autobackmysql.sh

2. 整理碎片

OPTIMIZE [LOCAL | NO_WRITE_TO_BINLOG] TABLE tbl_name [, tbl_name] …

 ㈠ optimize

内容如下:

2.1 使用alter table table_name engine = innodb命令进行整理。

 root@localhost [employees] 14:27:01> alter table t1   engine=innodb;

 Query OK, 0 rows affected (5.69 sec)
 Records: 0  Duplicates: 0  Warnings: 0

 root@localhost [employees] 14:27:15> show table status like 't1'G
 *************************** 1. row ***************************
           Name: t1
         Engine: InnoDB
        Version: 10
     Row_format: Dynamic
           Rows: 1191062
 Avg_row_length: 48
    Data_length: 57229312
Max_data_length: 0
   Index_length: 0
      Data_free: 2097152
 Auto_increment: NULL
    Create_time: 2018-08-28 14:27:15
    Update_time: NULL
     Check_time: NULL
      Collation: utf8mb4_general_ci
       Checksum: NULL
 Create_options: 
        Comment: 
 1 row in set (0.00 sec)

 

如果您已经删除了表的一大部分,或者如果您已经对含有可变长度行的表(含有VARCHAR, BLOB或TEXT列的表)进行了很多更改,则应使用

        

方法一:

2.2 使用pt-online-schema-change工具也能进行在线整理表结构,收集碎片等操作。

 [root@mysqldb1 14:29:29 /root]
 # pt-online-schema-change --alter="ENGINE=innodb" D=employees,t=t1 --execute
 Cannot chunk the original table `employees`.`t1`: There is no good index and the table is oversized. at /opt/percona-toolkit-3.0.11/bin/pt-online-schema-change line 5852.

 

 需表上有主键或唯一索引才能运行

 [root@mysqldb1 14:31:16 /root]
# pt-online-schema-change --alter='engine=innodb' D=employees,t=salaries --execute
No slaves found.  See --recursion-method if host mysqldb1 has slaves.
Not checking slave lag because no slaves were found and --check-slave-lag was not specified.
Operation, tries, wait:
  analyze_table, 10, 1
  copy_rows, 10, 0.25
  create_triggers, 10, 1
  drop_triggers, 10, 1
  swap_tables, 10, 1
  update_foreign_keys, 10, 1
Altering `employees`.`salaries`...
Creating new table...
Created new table employees._salaries_new OK.
Altering new table...
Altered `employees`.`_salaries_new` OK.
2018-08-28T14:37:01 Creating triggers...
2018-08-28T14:37:01 Created triggers OK.
2018-08-28T14:37:01 Copying approximately 2838426 rows...
Copying `employees`.`salaries`:  74% 00:10 remain
2018-08-28T14:37:41 Copied rows OK.
2018-08-28T14:37:41 Analyzing new table...
2018-08-28T14:37:42 Swapping tables...
2018-08-28T14:37:42 Swapped original and new tables OK.
2018-08-28T14:37:42 Dropping old table...
2018-08-28T14:37:42 Dropped old table `employees`.`_salaries_old` OK.
2018-08-28T14:37:42 Dropping triggers...
2018-08-28T14:37:42 Dropped triggers OK.
Successfully altered `employees`.`salaries`.

 

OPTIMIZE TABLE。被删除的记录被保持在链接清单中,后续的INSERT操作会重新使用旧的记录位置。您可以使用OPTIMIZE TABLE来重新

        optimize可以回收空间、减少碎片、提高I/O

##使用mysqldump备份数据库erms

2.3 使用optimize table命令,整理碎片。

运行OPTIMIZE TABLE, InnoDB创建一个新的.ibd具有临时名称的文件,只使用存储的实际数据所需的空间。优化完成后,InnoDB删除旧.ibd文件并将其替换为新文件。如果先前的.ibd文件显着增长但实际数据仅占其大小的一部分,则运行OPTIMIZE TABLE可以回收未使用的空间。

mysql>optimize table account;
 -------------- ---------- ---------- ------------------------------------------------------------------- 
| Table        | Op       | Msg_type | Msg_text                                                          |
 -------------- ---------- ---------- ------------------------------------------------------------------- 
| test.account | optimize | note     | Table does not support optimize, doing recreate   analyze instead |
| test.account | optimize | status   | OK                                                                |
 -------------- ---------- ---------- ------------------------------------------------------------------- 
2 rows in set (0.09 sec)

 

利用未使用的空间,并整理数据文件的碎片。

        目前支持的存储引擎有:InnoDB、MyASIM和ARCHIVE

/usr/local/MySQL/bin/mysqldump -uroot -ppwd erms >> /serverBack/mysql_back/erms_$(date "%Y_%m_%d").sql

3.整理表碎片shell脚本

# cat optimize_table.sh

#!/bin/sh
socket=/tmp/mysql3306.sock
time=`date "%Y-%m-%d"`
SQL="select concat(d.TABLE_SCHEMA,'.',d.TABLE_NAME) from information_schema.TABLES d where d.TABLE_SCHEMA = 'employees'"

optimize_table_name=$(/usr/local/mysql/bin/mysql -S $socket -e "$SQL"|grep -v "TABLE_NAME")

echo "Begin Optimize Table at: "`date "%Y-%m-%d %H:%M:%S"`>/tmp/optimize_table_$time.log

for table_list in $optimize_table_name
do

echo `date "%Y-%m-%d %H:%M:%S"` "alter table $table_list engine=innodb ...">>/tmp/optimize_table_$time.log
/usr/local/mysql/bin/mysql -S $socket -e "alter table $table_list engine=innoDB"

done
echo "End Optimize Table at: "`date "%Y-%m-%d %H:%M:%S"`>>/tmp/optimize_table_$time.log

输出内容

# cat optimize_table_2018-08-30.log

Begin Optimize Table at: 2018-08-30 08:43:21
2018-08-30 08:43:21 alter table employees.departments engine=innodb ...
2018-08-30 08:43:21 alter table employees.dept_emp engine=innodb ...
2018-08-30 08:43:27 alter table employees.dept_manager engine=innodb ...
2018-08-30 08:43:27 alter table employees.employees engine=innodb ...
2018-08-30 08:43:32 alter table employees.salaries engine=innodb ...
2018-08-30 08:44:02 alter table employees.t1 engine=innodb ...
2018-08-30 08:44:17 alter table employees.titles engine=innodb ...
2018-08-30 08:44:28 alter table employees.ttt engine=innodb ...
End Optimize Table at: 2018-08-30 08:44:28

 

 

使用方法:sh optimize.sh word

        

##找到/serverBack/mysql_back/下文件名称以erms_开头,以 .sql 结尾的文件,并且是7天前系统修改过的文件,将其删除

[[email protected] shell]#

        如果是Replication环境、可加NO_WRITE_TO_BINLOG(或者LOCAL、意思完全相同)、比如:

find /serverBack/mysql_back/ -mtime 7-name "erms_*.sql" -exec rm -rf {} ;

#!/bin/sh

        optimize local table table_name;

方法二:

time_log=/opt/optimize_time

        

/usr/local/mysql/bin/mysqldump -uroot -ppwd dbname > dir/db_`date %F`.sql

 

        以下是一个简单测试:

##保留近一周的备份文件,更早的删除

sum=$#

 

find /dir -mtime 7 -name"db_*.sql" -exec rm -rf {} ;

if [ "$sum" -eq 0 ]

[plain] 

方法三:

then

[[email protected] employees]$ ls -alh t.ibd  

filename='date %y%m%d'

echo "Error: no parameter chosed"

-rw-rw---- 1 mysql dba 24M 05-22 16:48 t.ibd  

/usr/local/mysql/bin/mysqldump -uroot-proot erms >>/serverBack/mysql/$filename.sql

exit 1

  

较全的shell脚本内容如下:

fi

未optimize前、有24M  

echo "---------------------------------------------------" >> /serverBack/dbBack/dbBackLog.log 

 

  

echo $(date "%Y-%m-%d %H:%M:%S") "erms Database backup start"  >> /serverBack/dbBack/dbBackLog.log 

for i in $*;do

mysql> optimize table t;  

/usr/local/mysql/bin/mysqldump -uroot -ppwd erms >> /serverBack/dbBack/erms_$(date "%Y-%m-%d").sql 

echo "optimize database $i starting ..."

------------- ---------- ---------- -------------------------------------------------------------------  

if [ 0 -eq $? ];then 

tables=$(/usr/bin/mysql $i -udevuser -pdevuser -e "show tables" | grep -v "Tables" > /opt/$i)

| Table       | Op       | Msg_type | Msg_text                                                          |  

if [ -f "/serverBack/dbBack/erms_$(date "%Y-%m-%d").sql" ];then 

tablelist=$(cat /opt/$i)

------------- ---------- ---------- -------------------------------------------------------------------  

echo $(date "%Y-%m-%d %H:%M:%S") "erms Database backup success!" >> /serverBack/dbBack/dbBackLog.log 

 

| employees.t | optimize | note     | Table does not support optimize, doing recreate analyze instead |  

else 

echo "optimize database $i starting ................" >> $time_log

| employees.t | optimize | status   | OK                                                                |  

echo $(date "%Y-%m-%d %H:%M:%S") "erms Database backup fail!" >> /serverBack/dbBack/dbBackLog.log 

echo "$i start at $(date [%Y/%m/%d/%H:%M:%S])" >> $time_log

------------- ---------- ---------- -------------------------------------------------------------------  

fi 

 

2 rows in set (3.82 sec)  

else 

for list in $tablelist

  

echo $(date "%Y-%m-%d %H:%M:%S") "erms Database backup error!" >> /serverBack/dbBack/dbBackLog.log 

do

--对于InnoDB的表、上面的内容并非报错、这是MySQL会帮你映射到:alter table table_name engine='InnoDB';  

fi 

echo $list

--MyISAM不会有这种情况  

echo "---------------------------------------------------" >> /serverBack/dbBack/dbBackLog.log 

/usr/bin/mysql $i -utaobao -padmin -e "optimize table $list"

  

find /serverBack/mysql_back/ -mtime 7 -name "erms_*.sql" -exec rm -rf {} ; 

done

[[email protected] employees]$ ls -alh t.ibd  

注意:a.这里的mysqldump最好是使用绝对路径,若直接使用mysqldump有可能备份成空文件

 

-rw-rw---- 1 mysql dba 14M 05-22 16:49 t.ibd  

b.为了确保该脚本内容准确无误,可以单独运行每个命令,如执行mysqldump命令:/usr/local/mysql/bin/mysqldump -uroot -ppwd erms >> /serverBack/mysql_back/erms_$(date "%Y_%m_%d").sql

echo "$i end at $(date [%Y/%m/%d/%H:%M:%S])" >> $time_log

    

c.find命令中,结尾处的 ; 分号不能省略

echo >> $time_log

optimize后、剩14M  

2.      添加一个定时任务

done

 

crontab –e ##编辑定时任务

...

     ㈡ check

添加定时任务内容:

        

00 15 * * * /serverBack/autobackmysql.sh  ##每天定时15:00:00 执行脚本 /serverBack/autobackmysql.sh

        检查表或视图的有无错误

命令:

        支持表引擎有:InnoDB和MyISAM

crontab –e ##编辑定时任务

        

crontab –r 删除所有定时任务

        下面简单模拟一个测试:

crontab –l 列出所有定时任务

 

本文永久更新链接地址:http://www.linuxidc.com/Linux/2017-05/143604.htm

[plain] 

图片 1

mysql> check table t;  

------------- ------- ---------- ----------  

| Table       | Op    | Msg_type | Msg_text |  

------------- ------- ---------- ----------  

| employees.t | check | status   | OK       |  

------------- ------- ---------- ----------  

1 row in set (0.63 sec)  

  

--没有错误的情况是这样的  

  

--用vim打开t.frm随意编辑两把  

  

mysql> check table tG;  

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

   Table: employees.t  

      Op: check  

Msg_type: Error  

Msg_text: Incorrect information in file: './employees/t.frm'  

*************************** 2. row ***************************  

   Table: employees.t  

      Op: check  

Msg_type: error  

Msg_text: Corrupt  

2 rows in set (0.00 sec)  

  

--报错了  

 

     ㈢ analyze

        

        用于收集优化器统计信息、和tuning相关、

        这个命令对 MyISAM、BDB、InnoDB 存储引擎的表有作用

        如果不想记录到binlog、也可加关键字local或者另外一个

 

[plain] 

mysql> analyze table tG;  

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

   Table: employees.t  

      Op: analyze  

Msg_type: Error  

Msg_text: Incorrect information in file: './employees/t.frm'  

*************************** 2. row ***************************  

   Table: employees.t  

      Op: analyze  

Msg_type: error  

Msg_text: Corrupt  

2 rows in set (0.00 sec)  

㈠ optimize optimize可以回收空间、减少碎片、提高I/O 目前支持的存储引擎有:InnoDB、MyASIM和ARC...

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