When I talked about the usability improvements of Tungsten Replicator, I did not mention the procedure for upgrading. I was reminded about it by a question in the TR mailing list, and since the question was very relevant, I updated the Tungsten Cookbook with some quick upgrading instructions. A quick upgrading procedure is as important as the installer. Since we release software quite often, either because we have scheduled features to release or because of bug fixes, users want to apply a new release to an existing installation without much fuss. You can do the upgrade with a very quick and painless procedure. Let's suppose that you have installed one Tungsten Replicator cluster using this command:

#
# using tungsten-replicator 2.0.4
# …

If you love a software product, you should try to improve it, and not be afraid of criticizing it. This principle has guided me with MySQL (where I have submitted many usability bugs, and discussed interface with developers for years), and it proves true for Tungsten Replicator as well. When I started working at Continuent, while I was impressed by the technology, I found the installation procedure and the product logs quite discouraging. I would almost say disturbing. Fortunately, my colleagues have agreed on my usability focus, and we can enjoy some tangible improvements. I have already mentioned the new installation procedure, which requires just one command to install a full master/slave cluster. I would like to show how you can use the new installer to deploy a multiple source …

So, we can have a look at this improvement, which I am sure will make DBAs quite happy. The new feature is an instantaneous exchange between a partition and a table with the same structure. Using this feature, you can transfer the contents of one partition to one table, and vice versa. Since the transition is done only in the attribution of the data, there is no copy involved. The data …

UPDATE This matter was more tricky than it appeared at first sight. As Bug#49861 shows, several MySQL engineers were …

Amy Hoy has written a blog post about why forums are crap. And she is right. Forum software does not always do a good job of helping people communicate. I have worked with Amy. She did a great analysis of dealnews.com that led to our new design. So, she is not to be ignored.

However, as a software developer (Phorum), I see a lot of problems and no answers.  And it is not all on the software.  Web site owners use forums to solve problems that they really, really suck at.  Ideally, every web site would be very unique for their audience.  They would use a custom solution that fits a number of patterns that best solves their problem.  However, most web site owners don't want to take the time to do such things.  They want a one stop, …

Jonas just wrote a patch to this bug on OPTIMIZE TABLE, and the issue that was also discussed in this blog post. Jonas also fixed this bug when he was at it.

Before, OPTIMIZE TABLE hardly freed up any pages and to defragment you had to do a rolling restart of the data nodes.

Now, there is only a 2% discrepancy between OPTIMIZE TABLE and doing a rolling restart. This is great stuff.
This will fix will make it into 6.3.26 and 7.0.7.

See below for details:

Creating two tables, t5 and t6:

CREATE TABLE `t5` (
`id` varchar(32) CHARACTER SET utf8 NOT NULL,
`name` varchar(32) …

There are some bug reports on the auto-discovery protocol in MySQL Cluster.
The idea of the auto-discovery protocol is to fetch the .frm files for the NDB tables stored in the data dictionary of the data nodes, and put them in the data directory of the mysql server.

However, sometimes (not always, which makes it more difficult to reproduce and hence fix), the auto-discovery seems to make strange things (from this bug report):

After shuting down and restoring my cluster I get the following error.

090211  9:59:26 [Note] NDB: mismatch in frm for panel.gatewayquestions, discovering...
090211  9:59:26 [Note] NDB Binlog: DISCOVER TABLE Event: REPL$panel/gatewayquestions
090211  9:59:26 [Note] NDB Binlog: logging ./panel/gatewayquestions (UPDATED,USE_WRITE)

This is due to the files already being in the mysql data directory. After …

A long standing bugAmong the many outstanding bugs for MySQL, there is one that has sparked a fierce discussion, not only in the bug report itself, but also in blogs, forums, mailing lists.
Bug #19027: MySQL 5.0 starts even with Fatal InnoDB errors was neglected for long time, until finally it got fixed, and it is available in MySQL 5.1.36.
First off, what is it about?
In short, if an engine doesn't initialize correctly, the MySQL server starts anyway, without the offending engine. Depending on how you use the failing engine, this could be either a minor annoyance or a complete disaster.
Annoyance: ARCHIVE fails to initialize, and you create tables with the default engine (usually MyISAM), and after a while you realize that the disk is filling up faster than you expected. You will find out eventually.
Disaster: ARCHIVE fails to …

Enter the sb script (available in version 3.0.03). Now I can shorten my typing experience with sandboxes quite a lot:

  $ sb 5135
  # same as calling 
  # …