Bug #96879 MyISAM I/O contention
Submitted: 15 Sep 2019 3:51 Modified: 15 Sep 2019 5:32
Reporter: Prudhvi Mutluri Email Updates:
Status: Not a Bug Impact on me:
Category:MySQL Server: MyISAM storage engine Severity:S1 (Critical)
Version:5.6.36 OS:CentOS (CentOS Linux release 7.3.1611 (Core))
Assigned to: CPU Architecture:x86 ( 3.10.0-514.16.1.el7.x86_64)

[15 Sep 2019 3:51] Prudhvi Mutluri
on out production mysql database we saw spike in slow queries which caused the application health checks fail.

from the monitoring tools we figured out there is spike in MyISAM wait/io/dfile/write.

Innodb engine stopped responding 

client connections jumped from 300 to 2000.

client thread activity spiked.

How to repeat:

more slow query logs slows down myisam engine

Suggested fix:
need help in this issue?
[15 Sep 2019 5:32] Shane Bester
We're sorry, but the bug system is not the appropriate forum for asking help on using MySQL products. Your problem is not the result of a bug.

For details on getting support for MySQL products see http://www.mysql.com/support/
You can also check our forums (free) at http://forums.mysql.com/

Thank you for your interest in MySQL.