Zabbix数据库表分区

zabbix的监控主机数量将近300，且运行了一年时间了，最近zabbix server服务监控历史数据等服务不断自身告警、查询性能也变得很低

关于历史数据的两个参数，在zabbix server的配置文件中

可以选择关闭housekeeper禁止自动定期清除历史记录数据，因为对于大数据的删除会直接影响zabbix的性能、或者调整相应参数

HousekeepingFrequency
取值范围：0-24
默认值：1
说明：housekeep执行频率，默认每小时回去删除一些过期数据。如果server重启，那么30分钟之后才执行一次，接下来，每隔一小时在执行一次。

MaxHousekeeperDelete
取值范围： 0-1000000
默认值：5000
housekeeping一次删除的数据不能大于MaxHousekeeperDelete

数据库优化

一、设置独立表空间（innodb_file_per_table=1）  # 5.6版本以上自动开启 以上版本跳过这一段

1、清空history数据

[root@Zabbix-Server ~]# mysql -u zabbix -p

MariaDB [(none)]> use zabbix;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
MariaDB [zabbix]>
MariaDB [zabbix]> truncate table history;
Query OK,  rows affected (0.19 sec)

MariaDB [zabbix]> optimize table history;
+----------------+----------+----------+-------------------------------------------------------------------+
| Table          | Op       | Msg_type | Msg_text                                                          |
+----------------+----------+----------+-------------------------------------------------------------------+
| zabbix.history | optimize | note     | Table does not support optimize, doing recreate + analyze instead |
| zabbix.history | optimize | status   | OK                                                                |
+----------------+----------+----------+-------------------------------------------------------------------+
 rows in set (0.81 sec)

MariaDB [zabbix]> truncate table history_str;
Query OK,  rows affected (0.05 sec)               

MariaDB [zabbix]>  truncate table history_uint;
Query OK,  rows affected (6.32 sec)

2、修改表结构

MariaDB [(none)]> use zabbix;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
MariaDB [zabbix]> Alter table history_text drop primary key, add index (id), drop index history_text_2, add index history_text_2 (itemid, id);
Query OK,  rows affected (1.11 sec)
Records:   Duplicates:   Warnings: 

MariaDB [zabbix]> Alter table history_log drop primary key, add index (id), drop index history_log_2, add index history_log_2 (itemid, id);
Query OK,  rows affected (0.14 sec)
Records:   Duplicates:   Warnings: 

修改完之后再按照官网上的过程创建四个存储过程：

3、将官方的四个分散代码拷贝至一个文件保存为sql，导入数据库；

cat /root/zabbix-partition.sql
DELIMITER $$
CREATE PROCEDURE `partition_create`(SCHEMANAME varchar(), TABLENAME varchar(), PARTITIONNAME varchar(), CLOCK int)
BEGIN
        /*
           SCHEMANAME = The DB schema in which to make changes
           TABLENAME = The table with partitions to potentially delete
           PARTITIONNAME = The name of the partition to create
        */
        /*
           Verify that the partition does not already exist
        */

        DECLARE RETROWS INT;
        SELECT COUNT() INTO RETROWS
        FROM information_schema.partitions
        WHERE table_schema = SCHEMANAME AND table_name = TABLENAME AND partition_description >= CLOCK;

        IF RETROWS =  THEN
                /*
                   1. Print a message indicating that a partition was created.
                   2. Create the SQL to create the partition.
                   3. Execute the SQL from #2.
                */
                SELECT CONCAT( "partition_create(", SCHEMANAME, ",", TABLENAME, ",", PARTITIONNAME, ",", CLOCK, ")" ) AS msg;
                SET @sql = CONCAT( 'ALTER TABLE ', SCHEMANAME, '.', TABLENAME, ' ADD PARTITION (PARTITION ', PARTITIONNAME, ' VALUES LESS THAN (', CLOCK, '));' );
                PREPARE STMT FROM @sql;
                EXECUTE STMT;
                DEALLOCATE PREPARE STMT;
        END IF;
END$$
DELIMITER ;

DELIMITER $$
CREATE PROCEDURE `partition_drop`(SCHEMANAME VARCHAR(), TABLENAME VARCHAR(), DELETE_BELOW_PARTITION_DATE BIGINT)
BEGIN
        /*
           SCHEMANAME = The DB schema in which to make changes
           TABLENAME = The table with partitions to potentially delete
           DELETE_BELOW_PARTITION_DATE = Delete any partitions with names that are dates older than this one (yyyy-mm-dd)
        */
        DECLARE done INT DEFAULT FALSE;
        DECLARE drop_part_name VARCHAR();

        /*
           Get a list of all the partitions that are older than the date
           in DELETE_BELOW_PARTITION_DATE.  All partitions are prefixed with
           a "p", so use SUBSTRING TO get rid of that character.
        */
        DECLARE myCursor CURSOR FOR
                SELECT partition_name
                FROM information_schema.partitions
                WHERE table_schema = SCHEMANAME AND table_name = TABLENAME AND CAST(SUBSTRING(partition_name FROM ) AS UNSIGNED) < DELETE_BELOW_PARTITION_DATE;
        DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

        /*
           Create the basics for when we need to drop the partition.  Also, create
           @drop_partitions to hold a comma-delimited list of all partitions that
           should be deleted.
        */
        SET @alter_header = CONCAT("ALTER TABLE ", SCHEMANAME, ".", TABLENAME, " DROP PARTITION ");
        SET @drop_partitions = "";

        /*
           Start looping through all the partitions that are too old.
        */
        OPEN myCursor;
        read_loop: LOOP
                FETCH myCursor INTO drop_part_name;
                IF done THEN
                        LEAVE read_loop;
                END IF;
                SET @drop_partitions = IF(@drop_partitions = "", drop_part_name, CONCAT(@drop_partitions, ",", drop_part_name));
        END LOOP;
        IF @drop_partitions != "" THEN
                /*
                   1. Build the SQL to drop all the necessary partitions.
                   2. Run the SQL to drop the partitions.
                   3. Print out the table partitions that were deleted.
                */
                SET @full_sql = CONCAT(@alter_header, @drop_partitions, ";");
                PREPARE STMT FROM @full_sql;
                EXECUTE STMT;
                DEALLOCATE PREPARE STMT;

                SELECT CONCAT(SCHEMANAME, ".", TABLENAME) AS `table`, @drop_partitions AS `partitions_deleted`;
        ELSE
                /*
                   No partitions are being deleted, so print out "N/A" (Not applicable) to indicate
                   that no changes were made.
                */
                SELECT CONCAT(SCHEMANAME, ".", TABLENAME) AS `table`, "N/A" AS `partitions_deleted`;
        END IF;
END$$
DELIMITER ;

DELIMITER $$
CREATE PROCEDURE `partition_maintenance`(SCHEMA_NAME VARCHAR(), TABLE_NAME VARCHAR(), KEEP_DATA_DAYS INT, HOURLY_INTERVAL INT, CREATE_NEXT_INTERVALS INT)
BEGIN
        DECLARE OLDER_THAN_PARTITION_DATE VARCHAR();
        DECLARE PARTITION_NAME VARCHAR();
        DECLARE OLD_PARTITION_NAME VARCHAR();
        DECLARE LESS_THAN_TIMESTAMP INT;
        DECLARE CUR_TIME INT;

        CALL partition_verify(SCHEMA_NAME, TABLE_NAME, HOURLY_INTERVAL);
        SET CUR_TIME = UNIX_TIMESTAMP(DATE_FORMAT(NOW(), '%Y-%m-%d 00:00:00'));

        SET @__interval = ;
        create_loop: LOOP
                IF @__interval > CREATE_NEXT_INTERVALS THEN
                        LEAVE create_loop;
                END IF;

                SET LESS_THAN_TIMESTAMP = CUR_TIME + (HOURLY_INTERVAL * @__interval * );
                SET PARTITION_NAME = FROM_UNIXTIME(CUR_TIME + HOURLY_INTERVAL * (@__interval - ) * , 'p%Y%m%d%H00');
                IF(PARTITION_NAME != OLD_PARTITION_NAME) THEN
      CALL partition_create(SCHEMA_NAME, TABLE_NAME, PARTITION_NAME, LESS_THAN_TIMESTAMP);
    END IF;
                SET @__interval=@__interval+;
                SET OLD_PARTITION_NAME = PARTITION_NAME;
        END LOOP;

        SET OLDER_THAN_PARTITION_DATE=DATE_FORMAT(DATE_SUB(NOW(), INTERVAL KEEP_DATA_DAYS DAY), '%Y%m%d0000');
        CALL partition_drop(SCHEMA_NAME, TABLE_NAME, OLDER_THAN_PARTITION_DATE);

END$$
DELIMITER ;

DELIMITER $$
CREATE PROCEDURE `partition_verify`(SCHEMANAME VARCHAR(), TABLENAME VARCHAR(), HOURLYINTERVAL INT())
BEGIN
        DECLARE PARTITION_NAME VARCHAR();
        DECLARE RETROWS INT();
        DECLARE FUTURE_TIMESTAMP TIMESTAMP;

        /*
         * Check if any partitions exist for the given SCHEMANAME.TABLENAME.
         */
        SELECT COUNT() INTO RETROWS
        FROM information_schema.partitions
        WHERE table_schema = SCHEMANAME AND table_name = TABLENAME AND partition_name IS NULL;

        /*
         * If partitions do not exist, go ahead and partition the table
         */
        IF RETROWS =  THEN
                /*
                 * Take the current date at 00:00:00 and add HOURLYINTERVAL to it.  This is the timestamp below which we will store values.
                 * We begin partitioning based on the beginning of a day.  This is because we don't want to generate a random partition
                 * that won't necessarily fall in line with the desired partition naming (ie: if the hour interval is 24 hours, we could
                 * end up creating a partition now named "p201403270600" when all other partitions will be like "p201403280000").
                 */
                SET FUTURE_TIMESTAMP = TIMESTAMPADD(HOUR, HOURLYINTERVAL, CONCAT(CURDATE(), " ", '00:00:00'));
                SET PARTITION_NAME = DATE_FORMAT(CURDATE(), 'p%Y%m%d%H00');

                -- Create the partitioning query
                SET @__PARTITION_SQL = CONCAT("ALTER TABLE ", SCHEMANAME, ".", TABLENAME, " PARTITION BY RANGE(`clock`)");
                SET @__PARTITION_SQL = CONCAT(@__PARTITION_SQL, "(PARTITION ", PARTITION_NAME, " VALUES LESS THAN (", UNIX_TIMESTAMP(FUTURE_TIMESTAMP), "));");

                -- Run the partitioning query
                PREPARE STMT FROM @__PARTITION_SQL;
                EXECUTE STMT;
                DEALLOCATE PREPARE STMT;
        END IF;
END$$
DELIMITER ;

[root@Zabbix-Server ~]# mysql -u zabbix -p zabbix
Enter password:
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is
Server version: 5.5.-MariaDB MariaDB Server

Copyright (c) , , Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [zabbix]> use zabbix;
Database changed
MariaDB [zabbix]> source /root/zabbix-partition.sql;
Query OK,  rows affected (0.04 sec)

Query OK,  rows affected (0.00 sec)

Query OK,  rows affected (0.00 sec)

Query OK,  rows affected (0.00 sec)

MariaDB [zabbix]> CALL partition_maintenance('zabbix', 'history_log', , , );
+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801100000,) |
+---------------------------------------------------------------+
 row in set (0.18 sec)

+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801110000,) |
+---------------------------------------------------------------+
 row in set (0.48 sec)

+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801120000,) |
+---------------------------------------------------------------+
 row in set (0.67 sec)

+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801130000,) |
+---------------------------------------------------------------+
 row in set (1.02 sec)

+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801140000,) |
+---------------------------------------------------------------+
 row in set (1.22 sec)

+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801150000,) |
+---------------------------------------------------------------+
 row in set (1.44 sec)

+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801160000,) |
+---------------------------------------------------------------+
 row in set (1.64 sec)

+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801170000,) |
+---------------------------------------------------------------+
 row in set (1.85 sec)

+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801180000,) |
+---------------------------------------------------------------+
 row in set (2.04 sec)

+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801190000,) |
+---------------------------------------------------------------+
 row in set (2.23 sec)

+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801200000,) |
+---------------------------------------------------------------+
 row in set (2.42 sec)

+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801210000,) |
+---------------------------------------------------------------+
 row in set (2.62 sec)

+---------------------------------------------------------------+
| msg                                                           |
+---------------------------------------------------------------+
| partition_create(zabbix,history_log,p201801220000,) |
+---------------------------------------------------------------+
 row in set (2.85 sec)

+--------------------+--------------------+
| table              | partitions_deleted |
+--------------------+--------------------+
| zabbix.history_log | N/A                |
+--------------------+--------------------+
 row in set (3.10 sec)

Query OK,  rows affected,  warning (3.10 sec)

4、对想要分区的表进行表分区

DELIMITER $$
CREATE PROCEDURE `partition_maintenance_all`(SCHEMA_NAME VARCHAR())
BEGIN
                CALL partition_maintenance(SCHEMA_NAME, 'history', , , );
                CALL partition_maintenance(SCHEMA_NAME, 'history_log', , , );
                CALL partition_maintenance(SCHEMA_NAME, 'history_str', , , );
                CALL partition_maintenance(SCHEMA_NAME, 'history_text', , , );
                CALL partition_maintenance(SCHEMA_NAME, 'history_uint', , , );
                CALL partition_maintenance(SCHEMA_NAME, 'trends', , , );
                CALL partition_maintenance(SCHEMA_NAME, 'trends_uint', , , );
END$$
DELIMITER ;
以上代码部分的含义为(库名,表名,保存多少天的数据,每隔多久生成一个分区,本次生成多少分区）

mysql> source /root/partition_maintenance_all.sql;
Query OK,  rows affected (0.00 sec)

mysql> CALL partition_maintenance_all('zabbix');

5、Housekeeper 设置

Zabbix用户界面中的 "Administration" -> "部分提供了所有选项。确保在右上角的下拉列表中选择"Housekeeping" 您应该看到类似于以下的屏幕：

• 确保“历史”和“趋势”两个选项的“启用内部管理”复选框未被选中。
• 确保历史和趋势的检查标题为“覆盖项目<趋势/历史>期间”复选框。
• 将历史和趋势的“数据存储期限（天数）”框设置为您保留两者的时间。在上面给出的表分区中，正确的值是7和365。

6、加入计划任务

不要让数据库用完你的分区，上面示例是如何创建14天额外分区的，在第15天，数据库将无法粘贴历史/趋势数据，因此会发生数据丢失。

所以每隔一段时间（通过cron或其他方法）重新运行这些存储过程。通过这样做，分区将始终存在，可以插入数据。

#Q-2018-1/9
30 4 * * 1  /usr/bin/mysql -uzabbix -pzabbix -e "use zabbix;" -e "CALL partition_maintenance_all('zabbix');"

实际在生产环境中上述操作运行一段时间后，Zabbix server的log文件会报如下错误，events表主键重复、主键不能自动增长、导致zabbix不能告警

  ::213930.461 [Z3005] query failed: [] Duplicate entry '' for key 'PRIMARY' [insert into events (eventid,source,object,objectid,clock,ns,value) values (,,,,,,);

可以使用如下命令删除events记录

[root@Zabbix-Server zabbix]# mysql -u zabbix -pzabbix  -e "use zabbix;"  -e 'delete from events';

如果想要删除表的所有数据，truncate语句要比 delete 语句快。

因为 truncate 删除了表，然后根据表结构重新建立它，而 delete 删除的是记录，并没有尝试去修改表。

不过truncate命令虽然快，却不像delete命令那样对事务处理是安全的。

另外注意的是mysql数据库清空表默认是不回收空间的（对应步骤1）

回收表空间的命令

optimize table history
optimize table history_uint

针对MySQL的不同数据库存储引擎，在optimize使用清除碎片，回收闲置的数据库空间，把分散存储（fragmented）的数据和索引重新挪到一起(defragmentation)，对I/O速度有好处。 
当然optimize在对表进行操作的时候，会加锁，所以不宜经常在程序中调用。可以参考http://www.cnblogs.com/w787815/p/8433548.html

zabbix社区文档参考

https://www.zabbix.org/wiki/Docs/howto/mysql_partition