Zabbix Mysql 分区

May I Suggest ?

#leanote #leanote blog #code #hello world

柯仓无居所

Zabbix Mysql 分区

? mysql分区 ? ? zabbix分区 ? ? zabbix_server 慢查询 ? ? zabbix ? 745 0 0

swimming ? mysql分区 ? ? zabbix分区 ? ? zabbix_server 慢查询 ? ? zabbix ?

# 分区详解 
> 近期zabbix 的mysql数据库越来越大，需要分区，分区按照文末操作即可，zabbix的mysql分区主要是通过系统crontab定时调用mysql中的过程，提前分区；此处做一些步骤的详解。

---

## 脚本导入

> 脚本需要放在服务器上倒入mysql即可，其中*partition_maintenance_all* 为调用过程，如果有需要按照调整增加或者减少需要分区的表或者时间：

```bash
DELIMITER $$
CREATE PROCEDURE `partition_create`(SCHEMANAME varchar(64), TABLENAME varchar(64), PARTITIONNAME varchar(64), 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(1) INTO RETROWS
        FROM information_schema.partitions
        WHERE table_schema = SCHEMANAME AND table_name = TABLENAME AND partition_description >= CLOCK;

IF RETROWS = 0 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(64), TABLENAME VARCHAR(64), 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(16);

/*
           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 2) 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(32), TABLE_NAME VARCHAR(32), KEEP_DATA_DAYS INT, HOURLY_INTERVAL INT, CREATE_NEXT_INTERVALS INT)
BEGIN
        DECLARE OLDER_THAN_PARTITION_DATE VARCHAR(16);
        DECLARE PARTITION_NAME VARCHAR(16);
        DECLARE OLD_PARTITION_NAME VARCHAR(16);
        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 = 1;
        create_loop: LOOP
                IF @__interval > CREATE_NEXT_INTERVALS THEN
                        LEAVE create_loop;
                END IF;

SET LESS_THAN_TIMESTAMP = CUR_TIME + (HOURLY_INTERVAL * @__interval * 3600);
                SET PARTITION_NAME = FROM_UNIXTIME(CUR_TIME + HOURLY_INTERVAL * (@__interval - 1) * 3600, '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+1;
                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(64), TABLENAME VARCHAR(64), HOURLYINTERVAL INT(11))
BEGIN
        DECLARE PARTITION_NAME VARCHAR(16);
        DECLARE RETROWS INT(11);
        DECLARE FUTURE_TIMESTAMP TIMESTAMP;

/*
         * Check if any partitions exist for the given SCHEMANAME.TABLENAME.
         */
        SELECT COUNT(1) 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 = 1 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 ;

DELIMITER $$
CREATE PROCEDURE `partition_maintenance_all`(SCHEMA_NAME VARCHAR(32))
BEGIN
# 此处三个数字分别表示为留存天数，分区时间长度（单位小时），分区数量（执行分区操作时分多少个区）
                CALL partition_maintenance(SCHEMA_NAME, 'history', 7, 24, 3);
                CALL partition_maintenance(SCHEMA_NAME, 'history_log', 7, 24, 3);
                CALL partition_maintenance(SCHEMA_NAME, 'history_str', 7, 24, 3);
                CALL partition_maintenance(SCHEMA_NAME, 'history_text', 7, 24, 3);
                CALL partition_maintenance(SCHEMA_NAME, 'history_uint', 7, 24, 3);
                CALL partition_maintenance(SCHEMA_NAME, 'trends', 365, 24, 3);
                CALL partition_maintenance(SCHEMA_NAME, 'trends_uint', 365, 24, 3);
END$$
DELIMITER ;
```

- 导入命令如下，后面的**zbx_db_partitiong.sql**为脚本名字：

```bash
mysql -u 'zabbix' -p'zabbixDBpass' zabbix < zbx_db_partitiong.sql
```

- 请注意：脚本导入后需要手动执行一下，命令如下：

```bash
/usr/bin/mysql -u 'zabbix' -p'xxxxxxx' zabbix -e "CALL partition_maintenance_all('zabbix');" > /tmp/CronDBpartitiong.log 2>&1
```

## 设置定时

> 将之前手动执行命令设置为系统定时任务，即可。

```bash
30 3 * * * /usr/bin/mysql -u 'zabbix' -p'xxxxxxx' zabbix -e "CALL partition_maintenance_all('zabbix');" > /tmp/CronDBpartitiong.log 2>&1
```

## 其他设置

- MYSQL设置

> mysql版本为5.7的话，会有一个索引条件下推对分区表不起作用的**BUG**，
类似 **select clock,ns,value from history_uint where itemid=123 and clock<=1460364250 and clock>1459759450 order by clock desc limit 1**
关于此问题，[国外参考地址](https://stackoverflow.com/questions/39023651/mysql-5-7-strange-perfomance-reduction-with-order-by-asc-desc-on-partitioned-tab)，[官方说明](https://support.zabbix.com/browse/ZBX-10652?focusedCommentId=188169&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-188169)，需要添加以下配置：

```bash
# mysqld中添加如下设置，防止出现跨区的满查询，
optimizer_switch=index_condition_pushdown=off
# 不重启修改参数
> set global optimizer_switch='index_condition_pushdown=off';
# 启用MySQL事件调度程序
event_scheduler = ON
# 不重启修改参数
> set global event_scheduler = ON;
```

- Zabbix 设置

> 
1. 将zabbix页面上的管家服务关闭。
2. zabbx—server内关于Housekeeper配置注销，重启zabbix-server服务。

## 检查分区

> 执行完以上操作后，重启数据库，进入数据库查看是否已创建分区表：

```bash
# 查看分区表
> show create table [tables_name]\G;
# 查看过程
> show procedure status;
# 删除过程
> drop procedure [partition_name];
```

---

国外参考网站：
[zabbix-mysql 分区五分钟](https://bestmonitoringtools.com/zabbix-partitioning-tables-on-mysql-database)

觉得不错，点个赞？

文章目录