I recently had a client ask me how to use Percona Toolkit tools with an SSL connection to MySQL (MySQL-SSL). SSL connections aren’t widely used in MySQL due to most installations being within an internal network. Still, there are cases where you could be accessing MySQL over public internet or even over a public “private” […]
MySQL replication is a core process for maintaining multiple copies of data – and replication is a very important aspect in database administration. In order to synchronize data between master and slaves you need to make sure that data transfers smoothly, and to do so you need to act promptly regarding replication errors to continue […]
Thank you to all of you who attended my webinar last week about Global Transaction IDs (GTIDs), which were introduced in MySQL 5.6 to make the reconfiguration of replication straightforward. If you missed my webinar, you can still listen to the recording and download the sides (free). We had a lot of questions during the […]
I was talking with a Percona Support customer earlier this week who was looking for Galera data on Percona Cloud Tools. (Percona Cloud Tools, now in free beta, is a hosted service providing access to query performance insights for all MySQL uses.) The customer mentioned they were already keeping track of some Galera stats on Cacti, and […]
I recently worked on a case where one node of a Galera cluster had its schema desynchronized with the other nodes. And that was although Total Order Isolation method was in effect to perform the schema changes. Let’s see what happened. Background For those of you who are not familiar with how Galera can perform […]
On Wednesday I gave a presentation on “How to Avoid Even More Common (but Deadly) MySQL Development Mistakes” for Percona MySQL Webinars. If you missed it, you can still register to view the recording and my slides. Thanks to everyone who attended, and especially to folks who asked the great questions. I answered as many as we had […]
This is the fourth post in our MySQL Fabric series. In case you’re joining us now, we started with an introductory post, and then discussed High Availability (HA) using MySQL Fabric here (Part 1) and here (Part 2). Today we will talk about how MySQL Fabric can help you scale out MySQL databases with sharding. Introduction At the […]
When you make a change to your MySQL configuration in production it would be great to know the impact (a “before and after” type of picture). Some changes are obvious. For many variables proper values can be determined beforehand, i.e. innodb_buffer_pool_size or innodb_log_file_size. However, there is 1 configuration variable which is much less obvious for many people […]
MySQL has status variables “questions” and “queries” which are rather close but also a bit different, making it confusing for many people. The manual describing it might not be very easy to understand:
The number of statements executed by the server. This variable includes statements executed within stored programs, unlike the Questions variable. It does not count COM_PING or COM_STATISTICS commands.
The number of statements executed by the server. This includes only statements sent to the server by clients and not statements executed within stored programs, unlike the Queries variable. This variable does not count COM_PING, COM_STATISTICS, COM_STMT_PREPARE, COM_STMT_CLOSE, or COM_STMT_RESET commands.
In a nutshell if you’re not using prepared statements the big difference between those is what “Questions” would count stored procedure calls as […]
First, I would like to invite you to my webinar, “Monitoring All (Yes, All!) MySQL Metrics with Percona Cloud Tools,” on Wednesday, June 25 at 10 a.m. Pacific Daylight Time, where I will talk on the new features in Percona Cloud Tools, including monitoring capabilities. In this post I’d like to show the cool and […]