Bug #88565 Contribution by Facebook: Add rpl_read_size option
Submitted: 20 Nov 2017 19:32 Modified: 31 Jan 13:52
Reporter: FBContrib Admin Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: Replication Severity:S3 (Non-critical)
Version:8.0 OS:Any
Assigned to: CPU Architecture:Any

[20 Nov 2017 19:32] FBContrib Admin
Description:
Background innformation provided by Facebook:
Abstract:

Repo: https://github.com/mysql/mysql-server

Patch on top of 8.0.3: https://github.com/mysql/mysql-server/commit/020025d9f277fd3283b8c75024f590857f58fbbd

Facebook commits: https://github.com/facebook/mysql-5.6/commit/58798f5

This adds the my.cnf variable "rpl_read_size" with a default value of 8kb. It must be a multiple of 4kb.

This sets the size for reads done from the relay log and binlog. Making it larger might help with IO stalls while reading these files when they are not in the OS buffer cache.

How to repeat:
See description

Suggested fix:
See contribution code attached
[20 Nov 2017 19:32] FBContrib Admin
Add rpl_read_size option 
(*) This code is contributed under the Facebook agreement

Contribution: fb_patch_10.txt (text/plain), 16.77 KiB.

[19 Jan 16:13] Omer Barnir
Thanks for your contribution, we will incorporate the patch into MySQL.
[31 Jan 13:52] Margaret Fisher
Posted by developer:
 
The following topics have been updated and should show in the build soon:

https://dev.mysql.com/doc/refman/8.0/en/replication-options-slave.html
Description of rpl_read_size

https://dev.mysql.com/doc/refman/8.0/en/replication-solutions-performance.html
Suggestion to use rpl_read_size