定时获取MySQL库的大小
获取数据库单个库的大小命令
```shell
[root@admin ~]# cat db_size.txt
mysql -h 192.8.1.1 -uUSER -pPASSWORD -e'use information_schema; select concat(round(((sum(DATA_LENGTH)+sum(INDEX_LENGTH))/1024/1024),2),"MB") as db_size from information_schema.tables where table_schema="db_name";'
```
将执行结果追加写入到一个文件中
```python
[root@admin ~]# cat db_size.py
#! /usr/bin/env python
import subprocess
import time
with open("db_size","r") as a:
b=a.readline().strip()
res = subprocess.Popen(
b.decode("utf-8"),
shell=True,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE, )
data = res.stdout.read().decode("utf-8").strip()+"\n\n"
with open("data_size","a",) as data_a:
data_a.write(time.strftime("%Y-%m-%d %H:%M:%S")+"\n")
data_a.write(data)
<h3>定时执行</h3>
```shell
[root@admin ~]# crontab -e
30 0 * * * /opt/db_size.py