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Displaying posts with tag: Insight for Developers (reset)
Q&A: Even More Deadly Mistakes of MySQL Development

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 time for  during the session, but here are all the questions with my complete answers:

Q: Disk bandwidth also not infinite

Indeed, you’re right! …

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High Availability with mysqlnd_ms on Percona XtraDB Cluster

This is the second part of my series on High Availability with mysqlnd_ms. In my first post, “Simple MySQL Master HA with mysqlnd_ms,” I showed a simple HA solution using asynchronous MySQL replication. This time we will see how to leverage an all-primary cluster where you can write to all nodes. In this post I used Percona XtraDB Cluster, but you should also be able to do the same with MySQL NDB Cluster or Tungsten Replicator.

To start with, here is the mysqlnd_ms configuration I used:

mysqlnd_ms_mm.ini

.  All of these files are available from my Github repository. Below, I have three Percona XtraDB Cluster nodes, …

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Simple MySQL Master HA with mysqlnd_ms

I had the pleasure of presenting to the PHP Users Group Philippines a few days ago about mysqlnd_ms. The mysqlnd plugin, MySQL Master Slave, is a transparent layer on top of mysqlnd extension. This allows you to do read-write splitting and slave reads load balancing without needing to change anything from your application. But do you know you can also achieve a form of high availability with this plugin? I shared 2 forms on my presentation, using async MySQL replication either in master-slave configuration or master-master configuration, while the second form is having an all primary cluster where you can write to all nodes.

This first part is to demonstrate how you can achieve a simple HA solution using the first form. First, all the sample code here can be found on my GitHub repository. So, to use the mysqlnd_ms plugin, it uses …

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TIMESTAMP Columns, Amazon RDS 5.6, and You

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 …

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Architecture and Design of MySQL-powered applications: June 11 Webinar

The architecture of MySQL-powered applications is one of my favorite topics to talk about. It’s a very important topic because if you do not get the architecture right then you’re very likely to fail with your project – either from the standpoint of failing with performance, high availability or security requirements… or failing to deliver on time and at the planned cost.

It’s also a great topic because there is so much knowledge available these days about MySQL-powered applications. MySQL has been around for a rather long time compared with many other solutions – and now we know what architectures have enabled people to build successful MySQL-powered applications and grow them to hundreds of millions of users as well as what applications did not work out.

This level of maturity really allows us to essentially take “off-the-shelf” MySQL architectures that can be used to build very …

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Why did we develop percona-agent in Go?

We recently open-sourced our percona-agent and if you check out the source code, you’ll find that it is written in the Go programming language (aka Golang). For those not up to speed, the percona-agent is a real-time client-side agent for Percona Cloud Tools.

Our requirements are quite demanding for our agents. This one is software that works on a real production server, so it must be fast, reliable, lightweight and easy to distribute. Surprisingly enough, binaries compiled by Go fit these characteristics.

There are of course alternatives that we considered. On the scripting side: Perl, Python, PHP, Ruby et al. These are not necessarily fast, and the distribution is also interesting. We have enough experience with …

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A technical WebScaleSQL review and comparison with Percona Server

The recent WebScaleSQL announcement has made quite a splash in the MySQL community over the last few weeks, and with a good reason. The collaboration between the major MySQL-at-scale users to develop a single code branch that addresses the needs of, well, web scale, is going to benefit the whole community. But I feel that the majority of community opinions and comments to date have been based on the announcement itself and the organizational matters only. What we have been missing is an actual look at the code. What actual new features and bug-fixes are there? Let’s take a look.

At the same time, as Percona is also a developer of an enhanced MySQL replacement database server, it’s natural to …

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Managing farms of MySQL servers with MySQL Fabric

While built-in replication has been a major cause for MySQL’s wide adoption, official tools to help DBAs manage replication topologies have typically been missing from the picture. The community has produced many good products to fill in this gap, but recently, Oracle has been filling it too with the addition of MySQL Utilities to the mix.

One part of the Utilities that has been generating interest recently is MySQL Fabric, and we will be discussing this project in an upcoming series of blog …

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How to find bugs in MySQL

Finding bugs in MySQL is not only fun, it’s also something I have been doing the last four years of my life.

Whether you want to become the next Shane Bester (who is generally considered the most skilled MySQL bug hunter worldwide), or just want to prove you can outsmart some of the world’s best programmers, finding bugs in MySQL is a skill not reserved anymore to top QA engineers armed with a loads of scripts, expensive flash storage and top-range server hardware. Off course, for professionals that’s still the way to go, but now anyone with an average laptop and a standard HDD can have a lot of fun trying to find that elusive crash…

 If you follow this post carefully, you may well be able to find a nice crashing bug (or two) running RQG

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Innodb redo log archiving

Percona Server 5.6.11-60.3 introduces a new “log archiving” feature. Percona XtraBackup 2.1.5 supports “apply archived logs.” What does it mean and how it can be used?

Percona products propose three kinds of incremental backups. The first is full scan of data files and comparison the data with backup data to find some delta. This approach provides a history of changes and saves disk space by storing only data deltas. But the disadvantage is a full-data file scan that adds load to the disk subsystem. The second kind of incremental backup avoids extra disk load during data file scans.

The idea is in reading only changed data pages. The information about what specific pages were changed is provided by the server itself which …

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