【Z投稿】大规模数据库监控的Zabbix玩法详谈
【Z投稿】大规模数据库监控的Zabbix玩法详谈
Oracle ACE for MySQL
10多年MySQL大规模数据库运维经验+8年Zabbix使用经验。本次峰会演讲和workshop《大规模数据库监控的Zabbix玩法》，讲述海量数据库实例的监控，介绍zabbix的安装、部署、优化，以及数据库自动化运维。
作者的话
从zabbix的1.6版本开始测试，1.8的版本开始线上使用，线上使用过1.9、2.0、2.2、3.0、4.0的版本，使用或是测试过zabbix1.6之后的所有版本。个人也有之前的SA转变为DBA，就zabbix的运维走数据库层面有一些自己的心得，希望对读者有所帮助。
1
MySQL版本推荐：MySQL5.7及以上版本，便捷的在线DDL方便zabbix的快速升级
链接方式：zabbix的server、proxy、MySQL数据库尽量使用域名方式连接，方便进行故障切换。
2
zabbix数据库的授权：
读写权限，用作zabbix自身访问：
grant all privileges on zabbix.* to 'zabbix'@'1.1.1.1' identified by 'zabbix';
只读权限，用作二次开发只读zabbix数据库：
grant SELECT on zabbix.* to 'zabbix_ro'@'1.1.1.1' identified by 'zabbixro';
3
MySQL配置文件需要调整的几个重要参数：
innodb_log_files_in_group = 16
innodb_log_file_size = 1G
innodb_file_per_table = 1
max_allowed_packet = 64M
back_log = 1024
max-connections = 2000
sync_binlog = 0
innodb_flush_log_at_trx_commit = 0
binlog_format = row
expire_logs_days = 3
4
使用SQL语句更新监控项或是触发器，提升变更效率，减少对数据库影响：
/*
update zabbix.items set delay=5 where key_='icmpping';
update zabbix.items t,zabbix.functions f set f.parameter='30' where f.itemid=t.itemid and t.key_='agent.ping'
*/
5
在做二次开发时，为避免对线上监控server端的影响，尽量使用独立的数据库从库读取数据（可能有大量通过API读取历史数据库等只读操作），需要一个只读的api接口，此时需要做zabbix数据库读写分离，可以在从库上过滤掉几张表，打开从库的写权限，这几张表主要用作用户登录的审计、session的记录，否则可能登录失败：
replicate-wild-ignore-table =zabbix.auditlog
replicate-wild-ignore-table =zabbix.sessions
replicate-wild-ignore-table =zabbix.ids
同时zabbix web_api做负载均衡的时候，请使用IP hash的方式，因为涉及到session的问题。
6
做zabbix的升级，其实是做zabbix数据库库表的变更，可能包含表结构的表更、索引的变更、数据的重组等操作，此时需要做一套新的数据库集群作为线上集群的存库存在，等数据同步完成，断掉同步，使用新的zabbix server程序连接新的数据库集群完成升级，升级完成后切换线上zabbix server、数据库域名到新的server和新的数据库上，这样能最低限度影响正常的监控。
7
数据库备份和数据情能力：
备份主要信息即可，监控数据和审计日志、events不需要备份，数据量太大。
历史数据的删除：包含监控历史详情数据和趋势数据，使用分区的方式进行删除；另外events表也要定时的清理，使用主键进行清理，保留5天左右的即可，并需要定期的进行碎片整理，否则监控大屏显示会逐步变慢。
8
zabbix server历史数据和趋势数据分区
https://www.zabbix.org/wiki/Docs/howto/mysql_partition
/* 为历史表分区做准备。zabbix2.0/3.0 only，3.2以上的版本不需要执行 */
ALTER TABLE history_text DROP PRIMARY KEY, ADD INDEX (id), DROP INDEX history_text_2, ADD INDEX history_text_2 (itemid, id);
ALTER TABLE history_log DROP PRIMARY KEY, ADD INDEX (id), DROP INDEX history_log_2, ADD INDEX history_log_2 (itemid, id);
/* 在server的配置文件中设置HousekeepingFrequency=0,禁用zabbix自带的清理历史数据任务 */
/*设置历史监控数据表中的时间字段为索引,方便后续按照时间取值二次开发*/
ALTER TABLE history ADD INDEX clock (clock);
ALTER TABLE history_log ADD INDEX clock (clock);
ALTER TABLE history_str ADD INDEX clock (clock);
ALTER TABLE history_str_sync ADD INDEX clock (clock);
ALTER TABLE history_sync ADD INDEX clock (clock);
ALTER TABLE history_text ADD INDEX clock (clock);
ALTER TABLE history_uint ADD INDEX clock (clock);
ALTER TABLE history_uint_sync ADD INDEX clock (clock);
ALTER TABLE trends ADD INDEX clock (clock);
ALTER TABLE trends_uint ADD INDEX clock (clock);
ALTER TABLE EVENTS ADD INDEX objectid (objectid,VALUE,clock);
/* 如果存在这五个存储过程则删除 */
DROP PROCEDURE IF EXISTS partition_create;
DROP PROCEDURE IF EXISTS partition_drop;
DROP PROCEDURE IF EXISTS partition_maintenance;
DROP PROCEDURE IF EXISTS partition_maintenance_all;
DROP PROCEDURE IF EXISTS partition_verify;
/*第一次执行存储过程*/
CALL partition_maintenance_all('zabbix');
/*
inser to crontab 每天执行一次存储过程，生成新的分区和删除老的分区
#!/bin/sh
/xxxxx/mysql/bin/mysql -uzabbix -pzabbixmonitor --socket=/xxxx/mysql/tmp/mysql.sock --database=zabbix -e "CALL partition_maintenance_all('zabbix');"
*/
存储过程详情如下：
/* partition_create */
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 ;
/* partition_drop */
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 ;
/* partition_maintenance */
DELIMITER $$
CREATE PROCEDURE `partition_maintenance`(SCHEMA_NAME VARCHAR(32), TABLE_NAME VARCHAR(32), KEEP_DATA_DAYS INT, HOURLY_INTERVAL INT, CREATE_NEXT_INTERVALS INT)
BEGIN
DECLARE OLDER_THAN_PARTITION_DATE VARCHAR(16);
DECLARE PARTITION_NAME VARCHAR(16);
DECLARE LESS_THAN_TIMESTAMP INT;
DECLARE CUR_TIME INT;
CALL partition_verify(SCHEMA_NAME, TABLE_NAME, HOURLY_INTERVAL);
SET CUR_TIME = UNIX_TIMESTAMP(DATE_FORMAT(NOW(), '%Y-%m-%d 00:00:00'));
SET @__interval = 1;
create_loop: LOOP
IF @__interval > CREATE_NEXT_INTERVALS THEN
LEAVE create_loop;
END IF;
SET LESS_THAN_TIMESTAMP = CUR_TIME + (HOURLY_INTERVAL * @__interval * 3600);
SET PARTITION_NAME = FROM_UNIXTIME(CUR_TIME + HOURLY_INTERVAL * (@__interval - 1) * 3600, 'p%Y%m%d%H00');
CALL partition_create(SCHEMA_NAME, TABLE_NAME, PARTITION_NAME, LESS_THAN_TIMESTAMP);
SET @__interval=@__interval+1;
END LOOP;
SET OLDER_THAN_PARTITION_DATE=DATE_FORMAT(DATE_SUB(NOW(), INTERVAL KEEP_DATA_DAYS DAY), '%Y%m%d0000');
CALL partition_drop(SCHEMA_NAME, TABLE_NAME, OLDER_THAN_PARTITION_DATE);
END$$
DELIMITER ;
/* partition_verify */
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 ;
/* partition_maintenance_all */
DELIMITER $$
CREATE PROCEDURE `partition_maintenance_all`(SCHEMA_NAME VARCHAR(32))
BEGIN
CALL partition_maintenance(SCHEMA_NAME, 'history', 28, 24, 14);
CALL partition_maintenance(SCHEMA_NAME, 'history_log', 28, 24, 14);
CALL partition_maintenance(SCHEMA_NAME, 'history_str', 28, 24, 14);
CALL partition_maintenance(SCHEMA_NAME, 'history_text', 28, 24, 14);
CALL partition_maintenance(SCHEMA_NAME, 'history_uint', 28, 24, 14);
CALL partition_maintenance(SCHEMA_NAME, 'trends', 730, 24, 14);
CALL partition_maintenance(SCHEMA_NAME, 'trends_uint', 730, 24, 14);
END$$
DELIMITER ;