MySQL Bugs: #113891: The value range of innodb_io_capacity

Bug #113891	The value range of innodb_io_capacity_max is changed.
Submitted:	5 Feb 3:23	Modified:	2 May 19:57
Reporter:	Zeng Zihao	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: InnoDB storage engine	Severity:	S3 (Non-critical)
Version:	8.0.36	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
The value ranged of innodb_io_capacity_max is changed from 2^64-1 to 2^32-1 on 64-bits machine. It is different from the website. https://dev.mysql.com/doc/refman/8.0/en/innodb-parameters.html#sysvar_innodb_io_capacity_m...

WL #14680 change the #define to constexpr.The max value of innodb_io_capacity_max was expressed as constexpr uint32_t SRV_MAX_IO_CAPACITY_LIMIT = ~0U; Therefore, it results the difference.

How to repeat:
mysql> set global innodb_io_capacity_max = 18446744073709551615;
Query OK, 0 rows affected, 1 warning (0.01 sec)

mysql> show warnings;
+---------+------+--------------------------------------------------------------------------+
| Level   | Code | Message                                                                  |
+---------+------+--------------------------------------------------------------------------+
| Warning | 1292 | Truncated incorrect innodb_io_capacity_max value: '18446744073709551615' |
+---------+------+--------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> show variables like 'innodb_io_capacity_max';
+------------------------+------------+
| Variable_name          | Value      |
+------------------------+------------+
| innodb_io_capacity_max | 4294967295 |
+------------------------+------------+
1 row in set (0.13 sec)

Hello Zeng Zihao,

Thank you for the report and feedback.
Verified as described.

regards,
Umesh

Posted by developer:
 
Thank you Zeng Zihao, the documentation was updated to reflect the changes made in 8.0.29+ via that worklog.

Posted by developer:
 
The changes for this (and other) options is now fixed in the documentation source. The following InnoDB options were unified (max = 2**32-1) where 32/64-bit no longer differ as of 8.0.37/8.4.1: innodb_io_capacity, innodb_log_wait_for_flush_spin_hwm, and innodb_lru_scan_depth.