MySQL Bugs: #97964: innodb_buffer_pool_size is set to 8mb by the installer on Windows occasionally

Bug #97964	innodb_buffer_pool_size is set to 8mb by the installer on Windows occasionally
Submitted:	12 Dec 2019 10:48	Modified:	24 Aug 2022 18:55
Reporter:	Nandor Varga	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL for Windows: Installer	Severity:	S2 (Serious)
Version:	8.0.18, 1.4.31.0	OS:	Windows (7/10/Server 2012/Server 2016)
Assigned to:		CPU Architecture:	x86 (various (after 2014))
Tags:	configuration, installer, performance, windows

Description:
The configuration part of the MySQL 8.0.18 Community (and 8.0.17) Windows installer (with default settings) can generate a my.ini file that will contain the following line on some configurations:

innodb_buffer_pool_size=8M

Because of this, the MySQL server will be virtually unusable in this day and age. The symptoms that led to my investigation was very slow (~50 Kb/s) InnoDB disk write times. After modifying the my.ini file by increasing this value, MySQL will go back to normal (i.e. disk write speeds above 1 Mb/s)

On other configurations, this line will be commented out by the installer (so the value will default to 128M)

#innodb_buffer_pool_size

This has been observed this on at least 4 machines: 
- virtual machines and physical machines
- Windows 7/10/Server 2012/Server 2016
- the system had at least 16 GB RAM in all cases
- Intel Xeon, 7th gen i5, 8th gen i7 CPUs
- with and without admin rights

How to repeat:
The reason of this behavior is still unclear to me, but I was able to reproduce the issue on a clean virtual machine: 

- VMWare Workstation 15 Player
- 16 GB RAM
- 6 CPU cores (systeminfo says "Intel64 family 6 Model 142 Stepping 11 GenuineIntel ~1992 Mhz)
- Windows 10 (10.0.17763)
- MySQL 8.0.18 Community
- default settings in the MySQL installer

Suggested fix:
There is no reason why anyone who uses Windows in 2019 would only want to have 8 MB for their innodb_buffer_pool_size, so the installer should set this value to 128M (or simply comment the line out) at all times.

Hello Nandor Varga,

Thank you for the bug report.
Verified as described.

Regards,
Ashwini Patil

Posted by developer:
 
Updated the 8.0, 5.7 and 5.6 templates to use the default of 128M for innodb_buffer_pool_size.

Posted by developer:
 
Fixed as of the upcoming MySQL Installer 1.6.4 release, and here's the proposed changelog entry from the documentation team:

In some cases, MySQL Installer templates could overwrite the
innodb_buffer_pool_size server variable’s default value (128M) with 8M.

Thank you for the bug report.