#######################sample
【OIP - 互联网开放平台】在2019-07-28 21:30:11发生10.194.42.19 - - Linux上的监控项【磁盘空间】【Free disk space on /db/mysql】产生了异常: 【严重】: 空闲磁盘空间低于10%, /db/mysql. 当前值: 9.6740 【珠海华润银行】
原因：
在问题出现时,登录MySQL,执行show processlist查看是否存在异常SQL.
1.mysql -uroot --socket=/db/mysql/data/mysqltmp/mysql.sock -p
Enter password:
mysql> show processlist
-> ;
+-----+-------------+-----------+------+---------+----------+-----------------------------------------------------------------------------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+-----+-------------+-----------+------+---------+----------+-----------------------------------------------------------------------------+------------------+
| 2 | system user | | NULL | Connect | 24025479 | Waiting for master to send event | NULL |
3 rows in set (0.00 sec)
2. mysql慢查询日志
mysql> show variables like '%slow%';
+---------------------------+------------------------------------------+
| Variable_name | Value |
+---------------------------+------------------------------------------+
| log_slow_admin_statements | OFF |
| log_slow_slave_statements | OFF |
| slow_launch_time | 2 |
| slow_query_log | ON |
| slow_query_log_file | /db/mysql/data/mydata/mysql-slow.log |
+---------------------------+------------------------------------------+
mysql> show variables like '%long%';
| long_query_time | 2.000000 |
慢查询时间为2s，
3.配置如下：
mysql> show variables like 'default_storage_engine';
+------------------------+--------+
| Variable_name | Value |
+------------------------+--------+
| default_storage_engine | InnoDB |
+------------------------+--------+
1 row in set (0.00 sec)
mysql> show variables like 'transaction_isolation';
Empty set (0.00 sec)
mysql> show variables like 'binlog_format';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| binlog_format | MIXED |
+---------------+-------+
1 row in set (0.00 sec)
mysql> show variables like 'binlog_cache_size';
+-------------------+---------+
| Variable_name | Value |
+-------------------+---------+
| binlog_cache_size | 2097152 |
+-------------------+---------+
1 row in set (0.00 sec)
mysql> show variables like 'max_binlog_cache_size';
+-----------------------+----------------------+
| Variable_name | Value |
+-----------------------+----------------------+
| max_binlog_cache_size | 18446744073709547520 |
+-----------------------+----------------------+
1 row in set (0.00 sec)
mysql> show variables like 'tmpdir';
+---------------+-------------------------------+
| Variable_name | Value |
+---------------+-------------------------------+
| tmpdir | /db/mysql/data/mydata/tmp |
+---------------+-------------------------------+
1 row in set (0.00 sec)
mysql> show variables like 'transaction_isolation';
Empty set (0.00 sec)
4.查看数据库容量
mysql> select
-> table_schema as 'db',
-> sum(table_rows) as 'count',
-> sum(truncate(data_length/1024/1024, 2)) as 'data(MB)',
-> sum(truncate(index_length/1024/1024, 2)) as 'index(MB)'
-> from information_schema.tables
-> group by table_schema
-> order by sum(data_length) desc, sum(index_length) desc;
+--------------------+----------+----------+-----------+
| db | count | data(MB) | index(MB) |
+--------------------+----------+----------+-----------+
| openapi | 21915376 | 11710.97 | 1216.19 |
| mysql | 2697 | 0.76 | 0.06 |
| information_schema | NULL | 0.00 | 0.00 |
| performance_schema | 74026 | 0.00 | 0.00 |
+--------------------+----------+----------+-----------+
4 rows in set (1.28 sec)
mysql> select
-> table_schema as 'db',
-> table_name as 'table',
-> table_rows as 'count',
-> truncate(data_length/1024/1024, 2) as 'data(MB)',
-> truncate(index_length/1024/1024, 2) as 'index(MB)'
-> from information_schema.tables
-> order by data_length desc, index_length desc;
+--------------------+----------------------------------------------------+---------+----------+-----------+
| db | table | count | data(MB) | index(MB) |
+--------------------+----------------------------------------------------+---------+----------+-----------+
| openapi | log_r_esb | 5312774 | 1957.00 | 0.00 |
| openapi | api_log_sys_0 | 2886067 | 1727.39 | 218.74 |
| openapi | api_log_sys_6 | 2795942 | 1673.90 | 217.91 |
| openapi | api_log_sys_5 | 2205103 | 1319.96 | 165.51 |
| openapi | api_log_sys_2 | 2114416 | 1264.59 | 163.54 |
| openapi | api_log_sys_3 | 2017041 | 1206.44 | 156.33 |
| openapi | api_log_sys_4 | 1910052 | 1142.62 | 143.61 |
| openapi | api_log_sys_1 | 1825220 | 1091.11 | 141.35 |
6.查看文件系统目录大小
[root@poipredis03 openapi]# du -s * |sort -nr
5971972 log_r_esb.ibd
1768856 api_log_sys_0.MYD
1714084 api_log_sys_6.MYD
1351648 api_log_sys_5.MYD
1294952 api_log_sys_2.MYD
1235412 api_log_sys_3.MYD
1179140 api_log_sys_1.MYD
1170056 api_log_sys_4.MYD
7．查看大表的engine
mysql> select table_catalog
-> ,table_schema
-> ,table_name
-> ,engine
-> from information_schema.tables
-> where table_schema='openapi' and table_name='log_r_esb';
+---------------+--------------+------------+--------+
| table_catalog | table_schema | table_name | engine |
+---------------+--------------+------------+--------+
| def | openapi | log_r_esb | InnoDB |
+---------------+--------------+------------+--------+
1 row in set (0.27 sec)
可能是因为表碎片，删除了数据，OS文件并不会收缩，但是表的大小是会变小的。所以就造成了OS文件里有了碎片化空间。
解决思路：
1.建议找操作系统人员扩容该目录/db/mysql
##########################
MySQL查看数据库表容量大小
https://cloud.tencent.com/info/429e1f0cadbc960659e7a43232450ae0.html
【https://blog.csdn.net/fdipzone/article/details/80144166】
1.查看所有数据库容量大小
|
1
2
3
4
5
6
7
8
|
select
table_schema
as
'数据库'
,
sum(table_rows)
as
'记录数'
,
sum(truncate(data_length/1024/1024, 2))
as
'数据容量(MB)'
,
sum(truncate(index_length/1024/1024, 2))
as
'索引容量(MB)'
from
information_schema.tables
group
by
table_schema
order
by
sum(data_length) desc, sum(index_length) desc;
|
2.查看所有数据库各表容量大小
|
1
2
3
4
5
6
7
8
|
select
table_schema
as
'数据库'
,
table_name
as
'表名'
,
table_rows
as
'记录数'
,
truncate(data_length/1024/1024, 2)
as
'数据容量(MB)'
,
truncate(index_length/1024/1024, 2)
as
'索引容量(MB)'
from
information_schema.tables
order
by
data_length desc, index_length desc;
|
3.查看指定数据库容量大小
例：查看mysql库容量大小
|
1
2
3
4
5
6
7
|
select
table_schema
as
'数据库'
,
sum(table_rows)
as
'记录数'
,
sum(truncate(data_length/1024/1024, 2))
as
'数据容量(MB)'
,
sum(truncate(index_length/1024/1024, 2))
as
'索引容量(MB)'
from
information_schema.tables
where
table_schema=
'mysql'
;
|
4.查看指定数据库各表容量大小
例：查看mysql库各表容量大小
|
1
2
3
4
5
6
7
8
9
|
select
table_schema
as
'数据库'
,
table_name
as
'表名'
,
table_rows
as
'记录数'
,
truncate(data_length/1024/1024, 2)
as
'数据容量(MB)'
,
truncate(index_length/1024/1024, 2)
as
'索引容量(MB)'
from
information_schema.tables
where
table_schema=
'mysql'
order
by
data_length desc, index_length desc;
|
查询整个MySQL实例里面存储引擎为MyISAM的表
select table_catalog
,table_schema
,table_name
,engine
from information_schema.tables
where engine='MyISAM';
查询MyDB数据库里面存储引擎为MyISAM的表
select table_catalog
,table_schema
,table_name
,engine
from information_schema.tables
where table_schema='MyDB' and engine='MyISAM';
###########################
http://blog.chinaunix.net/uid-16728139-id-3495657.html
分类： Mysql/postgreSQL
2013-02-22 14:48:20
原文地址：案例分享-MySQL服务器/tmp目录被占满 作者：ning_lianjie
案例分享-MySQL服务器/tmp目录被占满
描述:
MySQL服务器在每天的22点/tmp目录磁盘空间被占满,持续10分钟左右,然后自动恢复./tmp目录大小10G,平时可用空间8G左右.MySQL版本 5.5
分析
1. 在问题出现时,进入/tmp目录,ls –al查看具体文件.
2. 在问题出现时,登录MySQL,执行show processlist查看是否存在异常SQL.
3. 查看MySQL慢查询日志.
4. MySQL配置情况:
a) default_storage_engine = InnoDB
b) transaction_isolation = READ-COMMITTED
c) binlog_format = mixed
d) binlog_cache_size = 32K
e) max_binlog_cache_size = 18446744073709547520
f) tmpdir = /tmp
总结
1. InnoDB存储引擎,在READ-COMMITTED事务隔离级别的情况下(默认的级别是REPEATABLE-READ),普通的DELETE操作,在记录binlog的时候,会采用ROW模式.(暂时还不清楚原因,以后分析).
2. 程序在每天的22点,有一个清理的定时任务.自动删除R表的数据,如下:
delete from R where time < xxx;
将某天之前的数据清除.但是该表比较大,近50G.
3. MySQL参数
binlog_cache_size
max_binlog_cache_size
参考http://dev.mysql.com/doc/refman/5.5/en/replication-options-binary-log.html
4. 每次执行定时任务的时候,因为binlog记录的是ROW模式,再加上表的数据量比较大,binlog缓存一定会超过32K,结果就会在/tmp目录下生成临时文件(参考: When a thread that handles the transaction starts, it allocates a buffer of binlog_cache_size to buffer statements. If a statement is bigger than this, the thread opens a temporary file to store the transaction. The temporary file is deleted when the thread ends),MySQL默认配置,在64位系统情况下,binlog文件大小最大可以达到16EB.但是系统的/tmp目录是10G,所以事务执行一半,磁盘空间被占满,事务回滚.
5. 事后查看R表的数据以及binlog记录,验证了第4步的推论.
解决
在没有新数据写入的前提下,把确定保留的数据先放到新表里面,然后删除旧表,再把新表重命名.
create table R_20130220 select * FROM R where time >= xxx;
DROP TABLE R;
RENAME TABLE R_20130220 TO R;
隔天观察nagios和cacti监控,故障恢复.
https://www.2cto.com/database/201303/192747.html
######### binglog 太大，导致磁盘空间太满了。
mysql开启BINGLOG后日志文件增长比较快，很快占满磁盘空间。
mysql开启BINGLOG后日志文件增长比较快，很快占满磁盘空间。
cd /mysql/data/mydata
ls -ltr
-rw-rw---- 1 mysql mysql 1073742040 Jul 21 20:20 mysql-bin.000036
-rw-rw---- 1 mysql mysql 1073741977 Jul 23 21:33 mysql-bin.000037
-rw-rw---- 1 mysql mysql 1073742172 Jul 26 12:45 mysql-bin.000038
-rw-rw---- 1 mysql mysql 1073742485 Jul 28 10:45 mysql-bin.000039
通过以下几种方式删除日志文件：
一、设置日志保留时长expire_logs_days自动删除
查看当前日志保存天数：
show variables like '%expire_logs_days%';
这个默认是0，也就是logs不过期，可通过设置全局的参数，使他临时生效：
set global expire_logs_days=7;
设置了只保留7天BINLOG, 下次重启mysql这个参数默认会失败，所以需在my.cnf中设置
expire_logs_days = 7
二、手动删除BINLOG (purge binary logs)
用于删除列于在指定的日志或日期之前的日志索引中的所有二进制日志。这些日志也会从记录在日志索引文件
PURGE {MASTER | BINARY} LOGS TO ‘log_name’
PURGE {MASTER | BINARY} LOGS BEFORE ‘date’
例如：
PURGE MASTER LOGS TO ‘mysql-bin.010′;
PURGE MASTER LOGS BEFORE ‘2008-06-22 13:00:00′;
PURGE MASTER LOGS BEFORE DATE_SUB( NOW( ), INTERVAL 3 D