The TEXT and VARCHAR definitions in many db schemas are based on old information – that is, they appear to be presuming restrictions and behaviour from MySQL versions long ago. This has consequences for performance. To us, use of for instance VARCHAR(255) is a key indicator for this. Yep, an anti-pattern.

VARCHAR

In MySQL 4.0, VARCHAR used to be restricted to 255 max. In MySQL 4.1 character sets such as UTF8 were introduced and MySQL 5.1 supports VARCHARs up to 64K-1 in byte length. Thus, any occurrence of VARCHAR(255) indicates some old style logic that needs to be reviewed.

Why not just set the maximum length possible? Well…

A VARCHAR is subject to the character set it’s in, for UTF8 this means either 3 or 4 (utf8mb4) bytes per character can be used. So if one specifies VARCHAR(50) CHARSET utf8mb4, …

Many web hosting provider are looking for HA solution for the database backend they deliver to their customers.

Galera never became the perfect choice for these environment due to 2 factors:

1. no DBA really manage the databases
2. Galera runs database changes in Total Order Isolation

What does that really mean ? In fact, when you are a website hosting provider, you host the website (apache, nginx) on vhosts and you share a database server in which every customer has access to their own schema for their website.

Most of the time, those websites are CMS like Drupal, WordPress or Joomla (and certainly many others sharing the same …

Drupal is one of the most popular open source CMS applications available – and it runs primarily on a MySQL backend.  Out of the box, the schema is well tuned and indexed.  However, there are some ways to tweak the default installation to get more out of the system right from start.  Similarly, there is a fair bit of hidden flexibility (especially in the latest version) in terms of database configuration.

In a free MySQL webinar on Wednesday, November 13th at 1pm EST, I’ll go over some of the improvements in Drupal 7 in terms of database connectivity and operation as well as profile the default installation from the database perspective.  I’ll also be covering some of the ways to optimize the default application and detailing some of the ways to benchmark your installation.

The title …

Today we’re celebrating Percona’s 7th anniversary.  A lot has changed in these past 7 years – we have grown from a two-person outfit focused exclusively on consulting to a 100-person company with teammates in 22 different countries and 18 different states, now providing Support, Consulting, RemoteDBA, Server Development and Training services.

We also made our mark in open source software development, creating some of the most popular …

When looking at high availability for any CMS, and particularly for Drupal, the list of contenders for part or all of the solution is growing and can be daunting. We'll take a look at the various parts of a solution and what options we have.

Go Cloud?

It seems nearly every answer to every problem in IT these days is "The Cloud", but is it?

read more

When looking at high availability for any CMS, and particularly for Drupal, the list of contenders for part or all of the solution is growing and can be daunting. We'll take a look at the various parts of a solution and what options we have.

Go Cloud?

It seems nearly every answer to every problem in IT these days is "The Cloud", but is it?

read more

I have never been to a DrupalCon before so my first was DrupalCon Portland 2013 (with some 3,500+ attendees). My first DrupalCon happened to also be one that I spoke at, and I hope to return to Austin in 2014 (added bonus: I’ve never been to Texas before).

SkySQL had decided to get a booth at DrupalCon since I was speaking and I have to say that the booth was very successful. You may ask why and the simple reasons are:

1. Everyone at DrupalCon was a user of MySQL. Once they hit scale, they may need professional services or even just switch to MariaDB. This is a captive audience.
2. Everyone running Drupal at scale with many modules and nodes generally faced issues with database slowdowns. Hello …

Drupal is one of the most popular Content Management Systems (CMS) and is used increasingly in high-visibility sites, such as www.whitehouse.gov. This has brought a lot of attention on how to get the most performance out of Drupal and how to improve the availability of such sites. In this blog series I'll take you through the basics and on through to designing your own HA Drupal site.

But first, we need to understand what the challenges are in getting Drupal (or indeed any CMS) working on multiple servers in such a way as to ensure high availability and performance.

read more

Drupal is one of the most popular Content Management Systems (CMS) and is used increasingly in high-visibility sites, such as www.whitehouse.gov. This has brought a lot of attention on how to get the most performance out of Drupal and how to improve the availability of such sites. In this blog series I'll take you through the basics and on through to designing your own HA Drupal site.

But first, we need to understand what the challenges are in getting Drupal (or indeed any CMS) working on multiple servers in such a way as to ensure high availability and performance.

read more

So let’s clone our current Drupal 7.22 site from MySQL 5.1 that came with CentOS 6.4 and get it running on MySQL 5.6.

Upgrading MySQL 5.1 -> 5.6 has an official recommendation of making sure the intermediate 5.5 update is performed too. Please review Section 2.11.1 while you make a backup of all your data. Yes, you do have to make a backup. When you run the upgrade, there are tables in the mysql scehma that will be tweaked and skipping a step can make for a very messy late night in an attempt to recover.

An other thing to look for is that on occasion new reserved words are introduced that may conflict with column names in use in your schemas. So it pays to read through the release notes for new reserved words and then run a quick grep on your tables to be safe. If you find that there is a new reserved word …