April 20, 2014

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 […]

Integrating pt-online-schema-change with a Scripted Deployment

Recently, I helped a client that was having issues with deployments causing locking in their production databases.  At a high level, the two key components used in the environment were: Capistrano (scripted deployments) [website] Liquibase (database version control) [website] At a high level, they currently used a CLI call to Liquibase as a sub-task within […]

MySQL encryption performance, revisited

This is part two on a two-part series on the performance implications of in-flight data encryption with MySQL. In the first part, I focused specifically on the impact of using MySQL’s built-in SSL support with some rather surprising results. Certainly it was expected that query throughput would be lower with SSL than without, but I […]

MySQL & Sphinx: Register now for Nov. 20 Webinar

Sphinx is a free, open-source search server that integrates nicely with MySQL. It provides a fast, scalable, and pluggable search framework. The Sphinx engine possesses a variety of tools enabling you to customize how searching/indexing interacts with or becomes a part of your environment. Join me and Sphinx Search CEO/CTO Andrew Aksyonoff, the founder and creative […]

How Percona tested Percona Server 5.6: A world premiere in advanced testing

8PM. One of the servers found a critical bug. Hop online and discuss, log bug. 10PM. Patch ready. 10:30PM. New build ready. 10:45PM. New RQG run initiated. This was by no means an uncommon sight during the months of testing that went into Percona Server 5.6, in fact it was commonplace. At a certain point, […]

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 […]

How to Extract All Running Queries (Including the Last Executed Statement) from a Core File?

This post builds on the How to obtain the “LES” (Last Executed Statement) from an Optimized Core Dump? post written about a year ago. A day after that post was released, Shane Bester wrote an improved version, How to obtain all executing queries from a core file on his blog. Reading that post is key […]

How to recover an orphaned .ibd file with MySQL 5.6

A few years ago Yves Trudeau and Aleksandr Kuzminsky wrote posts about different ways for recovering orphaned .ibd files: Connecting orphaned .ibd files A recovery trivia or how to recover from a lost ibdata1 file Today I want to show you how to do that in more easy and quick way. In my example I’ll […]

MySQL on Windows: A survival guide for Linux-based DBAs

Next week, on Nov. 6, I will be delivering a webinar about running MySQL on Windows, with a strong focus on Linux-based sysadmins and DBAs – and how not to go crazy in the process. An interesting (and challenging!) part of working for Percona is that you never know what kind of setup a customer […]