by Ernie Souhrada | Sep 9, 2014 | Insight for DBAs, MySQL, Percona Software
A common migration path from standalone MySQL/Percona Server to a Percona XtraDB Cluster (PXC) environment involves some measure of time where one node in the new cluster has been configured as a slave of the production master that the cluster is slated to replace. In... by Ernie Souhrada | Jul 8, 2014 | Cloud, Insight for DBAs, Insight for Developers, MySQL
This comes from an issue that I worked on recently, wherein a customer reported that their application was working fine under stock MySQL 5.6 but producing erroneous results when they tried running it on Amazon RDS 5.6. They had a table which, on the working server,... by Ernie Souhrada | Apr 9, 2014 | Insight for DBAs, MySQL, Percona Software, Security
If you’ve been following this blog (my colleague, David Busby, posted about it yesterday) or any tech news outlet in the past few days, you’ve probably seen some mention of the “Heartbleed” vulnerability in certain versions of the OpenSSL... by Ernie Souhrada | Nov 18, 2013 | Benchmarks, Insight for DBAs, MySQL, Security
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... by Ernie Souhrada | Oct 10, 2013 | Benchmarks, Insight for DBAs, Insight for Developers, MySQL
NOTE: This is part 1 of what will be a two-part series on the performance implications of using in-flight data encryption.Some of you may recall my security webinar from back in mid-August; one of the follow-up questions that I was asked was about the performance... by Ernie Souhrada | Aug 26, 2013 | Insight for DBAs, Insight for Developers, MySQL, Webinars
Thanks to everyone who attended last week’s webinar on MySQL security; hopefully you’ve all gone out and set SELinux to enforcing mode if you weren’t already running that way. If you weren’t able to attend, the recording and slides are... by Ernie Souhrada | Jul 31, 2013 | Benchmarks, Insight for DBAs, Insight for Developers, MySQL
This is part 3 of a 3 part series covering the new InnoDB full-text search features in MySQL 5.6. To catch up on the previous parts, see part 1 or part 2Some of you may recall a few months ago that I promised a third part in my InnoDB full-text search (FTS) series, in... by Ernie Souhrada | Jun 7, 2013 | Insight for DBAs, Insight for Developers, MySQL, Webinars
Thanks to everyone who was in attendance on 05 June 2013 for my “Choosing a MySQL HA Solution” webinar. If you weren’t able to make it but are interested in listening to the presentation, it’s currently up and available for viewing over at... by Ernie Souhrada | May 28, 2013 | Insight for DBAs, MySQL, Percona Events, Webinars
Selecting the most appropriate solution for a MySQL HA infrastructure is as much a business and philosophical decision as it is a technical one, but often the choice is made without adequately considering all three perspectives. When too much attention is paid... by Ernie Souhrada | May 17, 2013 | Benchmarks, Hardware and Storage, MySQL
This is the second part in a two-part series comparing Virident’s vCache to FlashCache. The first part was focused on usability and feature comparison; in this post, we’ll look at some sysbench test results.Disclosure: The research and testing conducted... by Ernie Souhrada | May 16, 2013 | Benchmarks, Hardware and Storage, MySQL
(This is part one of a two part series) Over the past few weeks I have been looking at a preview release of Virident’s vCache software, which is a kernel module and set of utilities designed to provide functionality similar to that of FlashCache. In particular,... by Ernie Souhrada | Mar 21, 2013 | Benchmarks
Approximately 11 months ago, Vadim reported some test results from the Virident FlashMax 1400M, an MLC PCIe SSD device. Since that time, Virident has released the FlashMAX II, which promises both increased capacity and increased performance over the previous model. In... by Ernie Souhrada | Mar 4, 2013 | Insight for DBAs, Insight for Developers, MySQL
This is part 2 in a 3 part series on InnoDB MySQL full-text searches. In part 1, we took a quick look at some initial configuration of InnoDB full-text search and discovered a little bit of quirky behavior; here, we are going to run some queries and compare the result... by Ernie Souhrada | Feb 26, 2013 | Insight for DBAs, Insight for Developers, MySQL
I’ve never been a very big fan of MyISAM; I would argue that in most situations, any possible advantages to using MyISAM are far outweighed by the potential disadvantages and the strengths of InnoDB. However, up until MySQL 5.6, MyISAM was the only storage... by Ernie Souhrada | Feb 4, 2013 | Insight for DBAs, MySQL
Recently some of my fellow Perconians and I have noticed a bit of an uptick in customer cases featuring the following error message: SQLSTATE[HY000] [1135] Can't create a new thread (errno 11); if you are not out of available memory, you can consult the manual for a... by Ernie Souhrada | Dec 14, 2012 | Insight for DBAs, Insight for Developers, MySQL
Prior to version 5.0, MySQL could only use one index per table in a given query without any exceptions; folks that didn’t understand this limitation would often have tables with lots of single-column indexes on columns which commonly appeared in their WHERE... by Ernie Souhrada | Oct 27, 2012 | Insight for DBAs, Insight for Developers, MySQL
A few weeks back, I was working on a customer issue wherein they were observing database performance that dropped through the floor (to the point of an outage) roughly every 4 weeks or so. Nothing special about the environment, the hardware, or the queries; really,... by Ernie Souhrada | Sep 4, 2012 | Insight for DBAs, Insight for Developers, MySQL
Inspiration for this post is courtesy of a friend and former colleague of mine, Greg Youngblood, who pinged me last week with an interesting MySQL puzzle. He was running Percona Server 5.5.21 with a table structure that looks something like this: CREATE TABLE foo ( id... by Ernie Souhrada | Jun 21, 2012 | Insight for DBAs, MySQL
The MySQL manual tells us that regardless of whether or not we use “SET FOREIGN_KEY_CHECKS=0” before making schema changes, InnoDB will not allow a column referenced by a foreign key constraint to be modified in such a way that the foreign key will...