MySQL Bugs: #100512: adaptive hash index(AHI) building causing contention on btr_search

Bug #100512	adaptive hash index(AHI) building causing contention on btr_search_latches
Submitted:	13 Aug 2020 9:17	Modified:	17 May 2022 13:50
Reporter:	Zhou Xinjing (OCA)	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: InnoDB storage engine	Severity:	S5 (Performance)
Version:	5.7.31,8.0.21	OS:	Linux (3.10.107)
Assigned to:		CPU Architecture:	x86 (96 cores)
Tags:	performance

File:	Maximum allowed size is 50MB.
Description:
Privacy:

If the data you need to attach is more than 50MB, you should create a compressed archive of the data, split it to 50MB chunks, and upload each of them as a separate attachment.

To split a large file:

On *nix platforms use the split command e.g. split -b 50MB <my_large_archive> <my_split_archive_prefix>
On windows use WinZip or a similar utility to split the large file

This patch implements the idea described above

Attachment: ahi_build_contention_avoidance.patch (application/octet-stream, text), 870 bytes.

Visualization of the experiment on 8.0.21

Attachment: 8.0.21, oltp_read_only, 200GB BP, 100GB table, 256 users.pdf (application/pdf, text), 62.49 KiB.

Visualization of the experiment on 8.0.21.

Attachment: vis.pdf (application/pdf, text), 62.49 KiB.