Event_Scheduler Huge memory leak in MySQL 8 version

[Manoj Soni]

Hi All,

My Current Scenario is want to go in MySQL version 8 but getting lots of performance issues and drastically huge memory leak.


I observed in MySQL 8 version the event schedule thread is constantly utilizing the memory.

Test Case:

-> Create a simply 10 test events and schedule it on MySQL version 5.7 and version 8.

Do not try to call any procedure through event nor any dml operations.
------------------------------------------------------------------------

DELIMITER $$

ALTER DEFINER=`root`@`%` EVENT `call_TestEvents01` ON SCHEDULE EVERY 5 SECOND STARTS '2019-06-12 07:00:00' ON COMPLETION PRESERVE ENABLE DO BEGIN

-- CALL TestScheduler();

END$$

DELIMITER ;
------------------------------------------------------------------------

Now my observation is that whenever I have checked the event how much does the memory consumes for event scheduler and I have found out the syntax to check the current memory allocation for that we need to ON the performance_schema and also need to update the memory instrument to get the output for it.
------------------------------------------------------------------------
UPDATE performance_schema.setup_instruments
SET ENABLED = 'YES'
WHERE NAME LIKE 'memory/%';
------------------------------------------------------------------------
The syntax for monitoring the memory allocation for all the threads.

SELECT thread_id tid, USER, current_count_used ccu, current_allocated ca, current_avg_alloc caa, current_max_alloc cma, total_allocated FROM sys.memory_by_thread_by_current_bytes;

check the rows for USER: 'sql/event_scheduler' or you can use it through where clause
------------------------------------------------------------------------
You won't see the output until and unless we enable the setup of memory instruments

Now observe with the syntax for at least 2 days and you will identify that on the filed "current_allocated ca " is increasing constantly on MySQL version 8 in GB.

But in MySQL version 5.7 it will hold up with a certain amount of memory in MB.

You will get the major differences in version 8 and version 5.7.

Can anyone give some suggestions on it why does it consume too much of memory?

I would really appreciate to help out on this scenario as soon as possible.



Thanks