Bug #108171 innodb_ddl_threads not effective
Submitted: 17 Aug 2022 18:06 Modified: 18 Aug 2022 11:38
Reporter: xincheng xie Email Updates:
Status: Unsupported Impact on me:
None 
Category:MySQL Server Severity:S2 (Serious)
Version:8.0.27 OS:Linux
Assigned to: CPU Architecture:x86

[17 Aug 2022 18:06] xincheng xie 
Description:

I compiled a mysql-server (8.0.27),and then breakpoint at ddl0ctx.cc:151,
i watch the  n_threads  has No change with variable 'innodb_ddl_threads'，how to 
eplain this phenomenon，because m_max_buffer size has  change with variable 'innodb_ddl_buffer_size'

How to repeat:
change the innodb_ddl_threads   and debug it at  ddl0ctx.cc:151

Suggested fix:
Can this variable really be changed
[18 Aug 2022 1:35] zhai weixiang 
this is a session level variable, possiblely you may need to  SET SESSION INNODB_ddl_threads = ??
[18 Aug 2022 11:38] MySQL Verification Team 
Hi Mr. xie,

Thank you for your bug report.

However, you are using an old release. Please, let us know how this variable behaves in 8.0.30. Also, do not like whether variable is changed in a debugger, but, please use I_S commands to see whether the number has changed.

Unsupported.