The binary version for MySQL Cluster 7.2.10 has now been made available at http://www.mysql.com/downloads/cluster/ (GPL version) or https://support.oracle.com/ (commercial version).

A description of all of the changes (fixes) that have gone into MySQL Cluster 7.2.10 (compared to 7.2.9) is available from the 7.2.10 Change log.

A beautiful picture is sometimes better than words :

With standard HDDs (here in RAID 10), the innodb_io_capacity variable may have non expected effects.

You can see on this picture the result of a test on one of my server with only the replication thread activated. The value of the innodb_io_capacity variable was the single modification during the period.

So, don’t touch this parameter without a strong reason…
(Of course 30000 was a bit snooty)

[MAJ 2013-01-08] : I know 30k is a too high value for innodb_io_capacity, I used this value to make the graphe really eloquent.
Read this excellent post from Chris for more details : http://www.chriscalender.com/?p=201

…

If you aren’t familiar with MySQL replication, “Replication enables data from one MySQL database server (the master) to be replicated to one or more MySQL database servers (the slaves). Replication is asynchronous by default – slaves need not to connected permanently to receive updates from the master. This means that updates can occur over long-distance connections and even over temporary or intermittent connections such as a dial-up service. Depending on the configuration, you can replicate all databases, selected databases, or even selected tables within a database.” (From: http://dev.mysql.com/doc/refman/5.5/en/replication.html).

I use MySQL replication on my home office server. I don’t really have much data to store, but it is nice to have several replicated slaves for backup purposes and also for testing new replication features of MySQL. I …

MySQL 5.6 seems to be ready for GA. I have no inside information about it, but from some clues collected in various places I feel that the release should not be far away. Thus, it's time for some serious testing, and for that purpose I have worked at updating MySQL Sandbox with some urgent features.

I have just released MySQL Sandbox 3.0.28, with more support for MySQL 5.6. Notably in this release, there is suppression of MySQL 5.6 annoying verbosity, additional suppression of more annoying warnings ( actually a bug) when using empty passwords on …

I’ve written a lot about modeling MySQL with the USL, and I like it best of all the scalability models I’ve seen, but it’s not the only way to think about scalability. I was aware that New Relic supports a scalability chart, so I decided to take a peek at that. Here’s a screenshot of the chart, from their blog: Here’s how it works. It plots response time (or database time, or CPU) as the dependent variable, versus throughput as the independent variable.

I wish you all my best wishes for this new year.
I hope 2013 will be as exciting as 2012 for the MySQL community.

Thank you for spending time on MySQL[Plus] in 2012, I hope to have more and more readers in 2013.

If you would like to read (or read back) my posts published in 2012, here is the summary :

• How to quickly identify queries with pt-query-digest and pt-query-advisor from rules?
• A (little) MySQL bug story…
• Temporary file behavior… (and how lsof save my life) …

While testing MySQL 5.6, I came across some curious values for the new values used to set the crash-safe slave tables. To get safety, we need to set relay_log_info_repository and master_info_repository to 'TABLE'. That way, the replication information, instead of going to a file, will be saved to two tables in the mysql schema (mysql.slave_relay_log_info and mysql.slave_master_info).

So I was setting these values back and forth between 'FILE' and 'TABLE', until I made a "mistake." Instead of typing

set global relay_log_info_repository='table';

I wrote

set global relay_log_info_repository=1;

To my surprise, it did what I …

Last time I said that you can set a starting value for the USL’s coefficient of performance and let your modeling software (R, gnuplot, etc) manipulate this as part of the regression to find the best fit. However, there is a subtlety in the USL model that you need to be aware of. Here is a picture of the low-end of the curve:

The graph shows the USL model as the blue curve and linear scalability as the black line. Notice that at concurrencies less than 1, the value of the USL function is actually greater than the linear scalability function. This deserves some thought and explanation, because it can cause problems.

If you think about it, concurrency between one and zero is impossible. In fact, concurrency is not a smooth function, it is a step function. There can be zero requests resident in the system, one …

In On learning InnoDB: A journey to the core I introduced a new library and command-line tool in the innodb_ruby project. Later on in A quick introduction to innodb_ruby I walked through installation and a few quick demos of the innodb_space command-line tool.

In my last post, Page management in InnoDB space files, I described InnoDB’s extent, file segment, and free space management structures. Now I will provide a few demonstrations of using innodb_space to examine those structures in real tables.

(Note that if you have installed innodb_ruby before, you …

A new version of the BSD licensed, MySQL compatible C client library, called Libdrizzle (5.1.1 codename Carbrooke) has been released today.

Since the last release (less than 2 weeks ago) the diff is 7725 lines long, 224KB in size.  So we have been really busy :)

There have been a few API changes in this version, especially around the prepared statement API.  We have made this API much simpler to use.  So applications will very likely need slight modifications and recompiling.

Major changes in this version:

• Windows support (using MinGW) - Big thanks to Brian Aker, he worked very hard on this
• More cleanups and improvements to the general API
• Faster, more stable non-blocking connection handling - Something else Brian has been working hard on
• Almost the entire prepared statement user …