A client recently asked me if I could get the hostname or IP address of every server a MySQL user was using to connect for the past 30 days. I never thought of retrieving login information retrospectively. I wasn't sure if I could. Spoiler alert: it is only possible...
Unused indexes warrant an evaluation for several reasons. It can be a red flag that the MySQL Optimizer is not choosing to use the index, meaning that the index is not worth the effort to use. Additionally, unused indexes can take up valuable disk space. In MySQL...
Recently, I had a client that had a rack-mounted server that went into a hard lock on a Saturday morning. Monday morning, when it could be rebooted, MySQL received the dreaded "Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Could...
Patching the operating system is essential to keeping your server secure and performing optimally. Patching is as easy as running an apt-get update and apt-get upgrade. However, this can cause some unintended consequences. For one, MySQL server will also be upgraded...
Rotating MySQL logs is important because logs can take up a lot of disk space if left unmanaged. For example, an untuned database can lead to a lot of slow queries being logged. The error log can become large if it includes notes and warnings. Additionally, binlogs...
Database administrators need to know databases as well as the operating system (OS) their database is running on. Bash scripting is where the two merge. For the beginner, bash scripting can be intimidating, but all have the same basic structure: a beginning, middle,...
The error log is an important tool for troubleshooting. The size of the error log file can get quite large if left unattended. For starters, there are not many parameters that can be adjusted to impact its size in any way, unlike the binlog that has a few system...
Binary logs play an important role in replication and data recovery. In replication, source databases communicate data changes recorded in its binary logs to the replica's relay logs. They can also be used to repair a replica experiencing data drift. In a similar way,...
MySQL 5.6 reached its end-of-life (EOL) in February 2021. If you haven't upgraded to MySQL 5.7, you are not the only one. It can be an intimidating endeavor. There are configuration, system table, server, Innodb and SQL changes to consider. And, documentation is not...
When performing health checks on a database, I look at how many users are granted SUPER privileges. If you're reading this, you know why. SUPER privileges pose a potential security risk and should be limited to a few users that need this far-reaching access to...