Author - Carlos Tutte

Low Value in range_optimizer_max_mem_size Might Cause Full Table Scan

range_optimizer_max_mem_size Might Cause Full Table Scan

Although how range_optimizer_max_mem_size operates is explained in the official doc, it’s not a well-known variable and surely not a variable you need to modify under most circumstances. But from time to time we get some performance tickets related to this.
What problem does this variable cause if it is not properly sized? Let’s find out […]

Read more

Danger of Changing Default of log_error_verbosity on MySQL/Percona Server for MySQL 5.7

Changing Default of log_error_verbosity mysql

Changing the default value (3) of log_error_verbosity in MySQL/Percona Server for MySQL 5.7 can have a hidden unintended effect! What does log_error_verbosity do exactly? As per the documentation:
“The log_error_verbosity system variable specifies the verbosity for handling events intended for the error log.“
Basically a value of 1 logs only [Errors]; 2 is 1)+[Warnings]; and 3 […]

Read more

Deadlock Troubleshooting in Percona Server for MySQL 5.7

Deadlock Troubleshooting MySQL

Disclaimer: the following script only works for Percona Server for MySQL 5.7, and relies on enabling performance schema (PS) instrumentation which can add overhead on high concurrent systems, and is not intended for continuous production usage as it’s a POC (proof of concept).
Introduction
In Percona Support, we frequently receive tickets related to deadlocks and even […]

Read more

Percona Monitoring and Management 2 Docker Created Without pmm-data? No Problem!

PMM Docker Container Pmm-data

Disclaimer: This blog post is about migrating Percona Monitoring and Management 2 (PMM) data between PMM2 versions, and not for migrating data from PMM1 to PMM2. Restoring data from PMM1 to PMM2 is NOT supported since there were many architectural changes.
 
I recently worked on a customer case where he was not using a pmm-data […]

Read more

Improving MySQL Password Security with Validation Plugin

MySQL Password Security Plugin

In systems nowadays, improving security is a must! One of the weakest links in the security system is the user password from where an attacker can enter. In order to improve password strength and security, MySQL provides a plugin called “Validation plugin” which can be configured to enforce a set of rules for passwords.
 
Installation
The […]

Read more