zabbix 数据库数据清理

背景
因为zabbix历史数据过大，致使占用过多磁盘空间，需清理数据，释放空间

一、查看表占用空间状况

SELECT table_name AS "Tables",
round(((data_length + index_length) / 1024 / 1024), 2) "Size in MB"
FROM information_schema.TABLES
WHERE table_schema = 'zabbix'
ORDER BY (data_length + index_length) DESC;

二、分析表数据
从上面较大的表看，主要集中history_unit,history两张表，并且是存储历史数据，
a、查看history_uint和history数据表结构，能够根据clock时间戳来进行数据删除

MariaDB [zabbix]> desc history_uint;
+--------+---------------------+------+-----+---------+-------+
| Field  | Type                | Null | Key | Default | Extra |
+--------+---------------------+------+-----+---------+-------+
| itemid | bigint(20) unsigned | NO   | MUL | NULL    |       |
| clock  | int(11)             | NO   |     | 0       |       |
| value  | bigint(20) unsigned | NO   |     | 0       |       |
| ns     | int(11)             | NO   |     | 0       |       |
+--------+---------------------+------+-----+---------+-------+
4 rows in set (0.26 sec)

MariaDB [zabbix]> desc history;
+--------+---------------------+------+-----+---------+-------+
| Field  | Type                | Null | Key | Default | Extra |
+--------+---------------------+------+-----+---------+-------+
| itemid | bigint(20) unsigned | NO   | MUL | NULL    |       |
| clock  | int(11)             | NO   |     | 0       |       |
| value  | double(16,4)        | NO   |     | 0.0000  |       |
| ns     | int(11)             | NO   |     | 0       |       |
+--------+---------------------+------+-----+---------+-------+
4 rows in set (0.00 sec)

MariaDB [zabbix]>

三、清理表数据,建议中止zabbix server服务。
a、取30天前时间戳

[root@docker ~]# 
[root@docker ~]# date +%s -d "Jun 4, 2019 00:00:00"
1559577600
[root@docker ~]#

b、按照时间戳删除数据，并优化

delete from history where clock < 1559577600;
optimize table history

自动删除历史数据脚本：
#!/bin/bash
User="zabbix"
Passwd="zabbix"
Date=date -d $(date -d "-30 day" +%Y%m%d) +%s #取30天以前的时间戳
$(which mysql) -u${User} -p${Passwd} -e "
use zabbix;
DELETE FROM history WHERE 'clock' < $Date;
optimize table history;
DELETE FROM history_uint WHERE 'clock' < $Date;
optimize table history_uint;