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, contained two TIMESTAMP columns, one which defaulted to CURRENT_TIMESTAMP and the other which defaulted to ’0000-00-00 00:00:00′, like so:

CREATE TABLE mysql56 (
  id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
  ts1 TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  ts2 TIMESTAMP NOT NULL DEFAULT '0000-00-00 00:00:00',
);

However, under Amazon RDS, the same table looked like this:

CREATE TABLE rds56 ( 
  id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
  ts1 TIMESTAMP NULL DEFAULT NULL,
  ts2 TIMESTAMP NULL DEFAULT NULL, 
);

They mentioned that their schema contains TIMESTAMP column definitions without any modifiers for nullability or …

Yay! My first blog post! As long as at least 1 person finds it useful, I’ve done my job. Recently, one of my long-term clients was noticing that while their INSERTs were succeeding, a particular column counter was not incrementing. A quick investigation determined the column was of type int(11) and they had reached the maximum value of 2147483647. We fixed this by using pt-online-schema-change to change the column to int(10) unsigned, thus allowing values up to 4294967295.

My client was now concerned about all his other integer-based columns and wanted me to check them all. So I wrote a quick-n-dirty script in Go to check all integer-based columns on their current value compared to the maximum allowed for that column type.

You …

In the previous post of this series we saw how you could use mysqlrpladmin to perform manual failover/switchover when GTID replication is enabled in MySQL 5.6. Now we will review mysqlfailover (version 1.4.3), another tool from the MySQL Utilities that can be used for automatic failover.

Summary

• mysqlfailover can perform automatic failover if MySQL 5.6′s GTID-replication is enabled.
• All slaves must use --master-info-repository=TABLE.
• The monitoring node is a single point of failure: don’t forget to monitor it!
…

I recently had an opportunity to migrate a customer from a physical server into Amazon’s RDS environment. In this particular case the customers’ platform makes extensive use of MySQL triggers and views.  I came across two significant issues that prevented me from following Amazon’s documentation, which basically states “use mysqldump” but doesn’t call out a specific method of dealing with MySQL triggers and views.

Amazon Relational Database Service (Amazon RDS) is a great platform if you’re looking for complete hands-off management of your MySQL environment, but comes at a cost in the area of flexibility, i.e. you don’t have SUPER privilege and this brings up additional challenges.

1. You need to ensure you set log_bin_trust_function_creators=1 ( by default this is off, 0).
2. You need to clean up your mysqldump syntax.

#1 is easy, you simply make a configuration change …

On July 16 I’ll be presenting my next webinar focusing on common mistakes committed by MySQL users.

How to Avoid Even More of the Common (but Deadly) MySQL Development Mistakes

“Why can’t I just save my data to a file?”

Using an SQL database seems so complex to get right, and for good reason. The variety of data-driven applications is practically limitless, and as project requirements change, we find ourselves taking shortcuts and adopting bad habits. But there are proven methods to understanding how to develop and manage data in a scalable and reliable way. This talk shows you some of these methods, including:

• How to optimize a database application with partitioning and sharding.
• How to avoid the secret security …

MySQL Utilities are a set of tools provided by Oracle to perform many kinds of administrative tasks. When GTID-replication is enabled, 2 tools can be used for slave promotion: mysqlrpladmin and mysqlfailover. We will review mysqlrpladmin (version 1.4.3) in this post.

Summary

• mysqlrpladmin can perform manual failover/switchover when GTID-replication is enabled.
• You need to have your servers configured with --master-info-repository = TABLE or to add the --rpl-user option for the tool to work properly.
• The check for errant transactions is …

Earlier this month I wrote about vmstat iowait cpu numbers and some of the comments I got were advertising the use of util% as reported by the iostat tool instead. I find this number even more useless for MySQL performance tuning and capacity planning.

Now let me start by saying this is a really tricky and deceptive number. Many DBAs who report instances of their systems having a very busy IO subsystem said the util% in vmstat was above 99% and therefore they believe this number is a good indicator of an overloaded IO subsystem.

Indeed – when your IO subsystem is busy, up to its full capacity, the utilization should be very close to 100%. However, it is perfectly possible for the IO subsystem and MySQL with it to have plenty more capacity than when utilization is showing 100% – as I will show in an …

During last April’s Percona Live MySQL Conference and Expo, TokuDB celebrated it’s first full-year as an open source storage engine. I still remember reading the official announcement and the expectations it created one year ago. The premises were very interesting as it had the potential of helping MySQL manage “big data” in a way InnoDB just couldn’t. It also provided additional interesting features like “hot schema changes,” all the while making our dear flash storages last longer.

While I’ve kept an eye on the evolution of TokuDB this past year, I reckon I haven’t given it a try…. until recently, when a …

In my previous post I showed you how to setup Percona XtraDB Cluster 5.6 on Docker. This time I will show you how to setup Percona ClusterControl and add the existing Percona XtraDB Cluster 5.6 that we’ve managed to setup from the previous post.

Let us note the following details about our existing containers:

• 172.17.0.2 dockerpxc1
• 172.17.0.3 dockerpxc2
• 172.17.0.4 dockerpxc3
• 172.17.0.5 dockerccui-test

A quick tip for everyone who has followed my previous blog on setting up Percona XtraDB Cluster 5.6 on Docker: I did not …

We recently released a new version of Percona Cloud Tools with MySQL monitoring capabilities. Join me June 25 and learn the details about all of the great new features inside Percona Cloud Tools – which is now free in beta. The webinar is titled “Monitoring All (Yes, All!) MySQL Metrics with Percona Cloud Tools” and begins at 10 a.m. Pacific time.

In addition to MySQL metrics, Percona Cloud Tools also monitors OS performance-related stats. The new Percona-agent gathers metrics with fine granularity (up to once per second), so you are able to see any of these metrics updated real-time.

During the webinar I’ll explain how the new Percona-agent works and how to configure it. And I’ll demonstrate the standard dashboard with the most important MySQL …