July 22, 2014

Quick installation guide for Percona Cloud Tools for MySQL

Here in Percona Support, we’re receiving several requests per day for help with Percona Cloud Tools installation steps. So I decided to prepare a step-by-step example of the installation process with some comments based on experience.  Percona Cloud Tools is a hosted service providing access to query performance insights for all MySQL uses. After a […]

MySQL server memory usage troubleshooting tips

There are many blog posts already written on topics related to “MySQL server memory usage,” but nevertheless there are some who still get confused when troubleshooting issues associated with memory usage for MySQL. As a Percona support engineer, I’m seeing many issues regularly related to heavy server loads – OR OOM killer got invoked and […]

Beware of MySQL 5.6 server UUID when cloning slaves

The other day I was working on an issue where one of the slaves was showing unexpected lag. Interestingly with only the IO thread running the slave was doing significantly more IO as compared to the rate at which the IO thread was fetching the binary log events from the master. I found this out […]

How to recover table structure from .frm files with MySQL Utilities

Table structures are stored in .frm files and in the InnoDB Data Dictionary. Sometimes, usually in data recovery issues, we need to recover those structures to be able to find the lost data or just to recreate the tables. There are different ways to do it and we’ve already written about it in this blog. […]

[ERROR] mysqld: Sort aborted: Server shutdown in progress

Recently, one of our support customers faced this: “[ERROR] mysqld: Sort aborted: Server shutdown in progress.” At first it would appear this occurred because of a mysql restart (i.e. the MySQL server restarted and the query got killed during the stopping of mysql). However, while debugging this problem I found no evidence of a MySQL […]

2 cases for MySQL server overload

Your MySQL server is overloaded. You see hundreds of running queries in the SHOW PROCESSLIST taking many seconds to run, or can’t connect at all because all connections slots are busy. If you have worked with MySQL long enough you surely have seen it, probably more than once. This is what I would call “MySQL […]

MySQL Error: Too many connections

We have always received quite few questions here at Percona Support on how to avoid the dreaded “Too many connections” error, as well as what is the recommended value for max_connections. So, in this article I will try to cover best possible answers to these questions so others can mitigate similar kinds of issues. My […]

QA: Advanced Option Combinatorics (Pairwise Testing): Combinatorial mysqld Option Test Case Generation

How do we ensure that, when we have 35+ testable option combinations for mysqld, we test each and every combination of them? For example: will a different innodb_log_file_size combined with more innodb_log_files_in_group and a modified innodb_fast_shutdown setting truly not affect Percona’s log archiving feature? Most option-related bugs are caused by the setting of 1 or […]

Handling long-running queries in MySQL with Percona XtraBackup

I recently had a case where replication lag on a slave was caused by a backup script. First reaction was to incriminate the additional pressure on the disks, but it turned out to be more subtle: Percona XtraBackup was not able to execute FLUSH TABLES WITH READ LOCK due to a long-running query, and the […]

The benefits of a drop-in compatible MySQL alternative

Percona Server provides users with a variety of powerful benefits including enterprise-grade features, high performance in demanding use cases, rich diagnostics, and access to unique Percona XtraBackup capabilities, all for free and open source. In addition, Percona Server is a drop-in MySQL replacement. Compatibility with MySQL has important ramifications (as well as some risks) as Giuseppe Maxia highlighted in a […]