Most MySQL users have tried getting this rather cryptic error message: “MySQL server has gone away”. The MySQL documentation describes lots of possible reasons for this here: http://dev.mysql.com/doc/refman/5.1/en/gone-away.html

However this page is of little help for most users, I think. Dozens of reasons are listed, but except for the trivial ones (like physical connection was lost, the MySQL server or the machine where it runs has crashed etc.) there are a few reasons for this that are very common in our experience and a lot of those mentioned are not.

Here we will discuss one situation that to our experience happens very frequently for people working across multiple servers. The situation is that if a client sends a SQL-statement longer than the server max_allowed_packet setting, the server will simply disconnect the client. …

The latest package of Wordcraft, the PHP/MySQL based blog software that runs this site, is available for download from Google Code.  Just some minor bug fixes and cosmetic stuff.  Its getting a little use in the wild.  That is always fun to see.

Dear MySQL and Drupal , Plone and other Open Source folks, you might want to be interrested in giving a talk at T-Dose 2009 ,

Jean Paul pinged me with the following mail :

Maybe it escaped your attention that the Call For Papers for T-DOSE 2009 is already out. It has been announced on 12th of June 2009. Below you will find the original announcement.

Call for Papers and Projects
Fri, 06/12/2009 - 13:57 — jpsaman

T­-DOSE is a free and yearly event held in The Netherlands to promote use and development of Open Source Software. During this event Open Source projects, developers and visitors can exchange ideas and knowledge. It is held at the Fontys University of Applied Science on 3 and 4 October 2009.

Speakers can send ideas and abstracts to the organisation at abstracts _AT_ t-dose.org. The e­mail should contain a short biography of the speaker and description of the talk. All talks will be held …

The feed may look like this one:

Since I liked this post, I can click on Vote UP, and the link opens in my …

It is striking how much harder it is to make money from open source than to write it in the first place. Open source development is a sophisticated and well-understood social activity. However, the economic model is often laughably primitive: "if you build it, they will come." That applies to the question of turning your open source project into a real job. More interestingly, it applies to the question of how to make open source projects as valuable as possible to the largest number of people. In this post I would like to propose an answer to both questions.

To illustrate open source sophistication, just look how easy it has become to start and manage projects. It is almost a cookie-cutter procedure. You pick one of a number of well known licenses, manage the code on SourceForge.net or Launchpad, communicate with the project …

Every once in a while, I find myself needing to round a number up to the nearest even power of 10, or round a time interval to the nearest quarter of an hour, or something like that. This is actually quite simple, but for some reason I always find myself confused about how to do it. I have to reason it out all over again, instead of just remembering how to do it. Perhaps writing this blog post will help me remember next time.

The basic idea for rounding to whole multiples is to divide the number, losing precision. Then round, floor, or ceiling the resulting number, and multiply to get back to the original magnitude. For rounding to fractions, reverse the process: multiply, round and divide again.

This actually works for any programming language, not just SQL. But I find myself doing it in SQL most often.

Here’s an example of how to turn a year into a decade:

mysql> SELECT FLOOR(YEAR(NOW()) / 10) * 10 AS …

On Wednesday, August 12th there will be a webinar introducing new features in MySQL Cluster 7.0. Presenting are Andrew Morgan and Mat Keep (MySQL Cluster Product Management).
I'll be assisting the panel answering any questions you might have.  

Whether you're racing to introduce a new service, or trying to manage an avalanche of data in real time, your database has to be scalable, fast and highly available to meet ever-changing market conditions and stringent SLAs.

By attending this webinar, you will learn more about the next generation of MySQL Cluster, and how it enables you to deliver 99.999% database availability, with real time performance and linear scalability, while slashing TCO.

Boasting a range of breakthrough capabilities, MySQL Cluster 7.0 will enable you to stay ahead of your most demanding, mission-critical application requirements. Enhanced scalability delivers higher database performance with …

I was reviewing what I had written over the last 2 years, and how people had reacted via comments and page views, even what keywords were most popular.

Here is the first draft (pending input from interested readers via adding a comment)

1. More dbt2 benchmark articles.
2. Amazon EC2 LVM snapshots vs EBS snapshots.
3. Backup software for MySQL and specifically on EC2.
4. Benchmarking Amazon EBS using iozone.
5. Installing, testing and benchmarking the non-standard MySQL engines such as OurDelta and XtraDB and plugins.
6. Using EC2 as a test bed for new versions of MySQL and Oracle and other dbs.
7. New: Using Microsoft SQL …

If you were ever wondering what other people check out on this site, here are the most popular articles by pageviews for the last 12 months. Seems most people like the LVM snapshots article, articles about running multiple MySQL instances … Continue reading →