This Thursday (February 26th, 14:00 UTC), Lenz Grimmer will give a MySQL University session on Backing up MySQL using file system snapshots. Lenz is a member of the MySQL Community team and the maintainer of the mylvmbackup tool. mylvmbackup is a tool for quickly creating backups of a MySQL server's data files. To perform a backup, mylvmbackup obtains a read lock on all tables and flushes all server caches to disk, creates a snapshot of the volume containing the MySQL data directory, and unlocks the tables again. The snapshot process takes only a small amount of time. When it is done, the server can continue normal operations, while the actual file backup proceeds.

For MySQL University sessions, point …

Sorry for the downtime of this site - until around a week ago I hosted my home page on a trusty Genesi Pegasos II system (powered by a PowerPC G4 Processor clocked at 1GHz, using Debian 4.0 PPC with 512 MB of RAM), serving these pages from my home DSL connection. Unfortunately this system provided no means of redundancy - the hard disk drive died.

Luckily I perform frequent backups, so I moved most parts of the site to a shared hosting space now - the picture gallery is unfortunately too big to fit into the space that I have there. I'll try to move the pictures into my Flickr account instead, but this will take some time.

Note that the primary domain name of this site is now lenzg.net - lenzg.org, (the …

Let’s say you need to do a website that must support multiple languages for cultures as diverse as Japan, France, Russia, Saudi Arabia, and Brazil, as well as the US. This can be quite a daunting task, with all kinds of unexpected gotchas.

The ideal character set of choice is, of course, UTF8. Alas, you will note that most of the systems you’ll need to use defaults to LATIN1, including MySQL. If your site is written in PHP, that also by default is set to LATIN1.

I find it quite puzzling that in this day and age of globalization that many of the tools don’t default to UTF8. And there are major issues with this, because everything in the chain of delivery must either be set to UTF8 or can handle UTF8 or you’ll see bizarreness when you attempt to display the characters of some languages. You will probably see a series of question marks (“??? ??? ?????”) instead of the actual words. Sometimes you may see a series of squares. …

If you’re using Fedora 10, and are a KDE desktop user, you’ll notice that your latest KDE 4.2 update, requires having a local MySQL server installed. This is due to Akonadi, part of the KDE PIM packages, that now rely on MySQL as a default server, for storing PIM data. Just a few months ago, I mentioned the news that Amarok 2 will also use MySQL as a default database.

Akonadi uses MySQL mainly as a cache, not as a data store. This is something that Debian users will also see. Eventually, anyone with KDE 4.2 will see the requirement to have a MySQL server installed. If you already have a native installation of MySQL provided for by your distribution (maintained by RPM/DPKG), it …

Today I had to swap 2 columns in one of my MySQL tables. The task, which seems easily accomplishable by a temp variable, proved to be a bit harder to complete. But only just a bit.

Here are my findings:

1. The

   UPDATE swap_test SET x=y, y=x;

   approach doesn't work, as it'll just set both values to y.

   PostgreSQL seems to handle this query differently, as it apparently uses the old values throughout the whole query. [Reference]

2. Here's a method that uses a temporary variable. Thanks to Antony from the comments for the "IS NOT NULL" tweak. Without it, the query works unpredictably. See the table schema at the end of the post. This method doesn't swap the values if one of them is NULL. Use method #3 that doesn't have this limitation. …

Wow, check out what just came out from Linbit: The DRBD Management Console. Written in Java (so it runs anywhere), completely open source (GPLv3), and allows you to manage DRBD and Heartbeat based clusters. You can install, configure, see your systems graphically, and a lot more. I’m interested to try the beta out, as soon as I get back to my lab (sitting in the airport now). If you know how to use DRBD/Heartbeat, and use it in production for your MySQL setup, it might be a good application to test out, and improve if need be.

From the screenshots, I’m surprised this isn’t a value added extra that Linbit would like to charge for. Kudos, Linbit, for keeping it GPLv3!

…

How To Add Two-Factor Authentication To phpBB

This document describes how to add WiKID two-factor authentication to phpBB through Apache using mod_auth_xradius. Given the recent attack against phpBB and the exposure of it's users' passwords, we thought two-factor authentication might be timely.

I’m enamored by the middle path.

Basically, the idea is that extremism is an evil and often ideological perspectives are non-optimial solutions.

The Dalai Lama has pursued a middle path solution to the issue of Tibetan independence.

The two opposing philosophies in this situation are total and complete control of Tibet by the Chinese or complete political freedom by the Tibetan people and self governance. The Dalai Lama proposes an alternative whereby China and Tibet pursue stability and co-existence between the Tibetan and Chinese peoples based on equality and mutual co-operation.

How does this apply to Linux?

The current question of swap revolves around using NO swap at all or using swap to page out some portion of your application onto disk.

Even with …

The current size of a MySQL 5.1.30 installation is around 420M.

$ du -sh .
426M    .

A further breakdown.

$ du -sh *
213M    bin
20K     COPYING
9.8M    docs
8.0K    EXCEPTIONS-CLIENT
436K    include
12K     INSTALL-BINARY
121M    lib
504K    man
4.0K    my.cnf
77M     mysql-test
4.0K    README
20K     scripts
2.3M    share
2.9M    sql-bench
100K    support-files

A means to reduce the footprint by 25% is to delete some unused stuff.

$ rm -rf docs/ mysql-test/ sql-bench/
$ du -sh .
337M    .

It’s no big deal, however it certainly does cut down on verbose output in the backup logs removing the mysql-test directory and files.

Yesterday Sun introduced Glassfish Portfolio. Its a new stack of open source middleware products including Glassfish Enterprise Server, Glassfish ESB, Glassfish Web Space Server, and the new Glassfish Web Stack, which includes support for projects such as Tomcat, Memcached, Apache, PHP, Ruby and Python and a copy of MySQL Community.

It’s a pretty complete infrastructure stack. What it is not, however, is an integrated LAMP stack, despite Sun’s reference to it as such not once but twice on its press announcement.

Glassfish Portfolio runs on Linux of course, as well as Solaris, but it does not contain Linux (integrated or otherwise) or Linux services (although that is available …