MySQL accesses files in various places on the file system, and usually this isn't something to worry about. For example, in a standard MySQL 5.5 installation on Ubuntu, the data goes in /var/lib/mysql, and the socket is a file in /var/run/mysqld. It puts configuration files in /etc, logs and binaries in various locations, and it even needs to access some operating system files such as /etc/hosts.allow.

This is all very well until you start trying to be clever and get MySQL to access other parts of the file system. After all, you can configure the location of data, log files, socket, and so on, so why shouldn't you use those settings to optimize your system? Unfortunately, on many modern Linux distributions, it's not that always easy.

Take Ubuntu, for example. Ubuntu comes with something called AppArmor, a kernel-integrated application security system that controls how applications can access the file system. This goes above …

Tecnotree is a global provider of telecom IT solutions for the management of products, customers and revenue. Tecnotree helps communications service providers to transform their business towards a marketplace of digital services. Tecnotree empowers service providers to monetise on service bundles, provide personalized user experiences and augment value throughout the customer lifecycle. With over 1100 telecom experts, Tecnotree serves more than 100 service providers in over 70 countries. Tecnotree is listed on the main list of NASDAQ OMX Helsinki.

Challenges

• Integrate a database well suited to power the mission critical Tecnotree solutions deployed by telecom operators in networks counting over 50 million subscribers.
• Standardize on one database for the core Tecnotree products, while meeting the company’s technical and economic requirements.
• Select a database delivering the configuration …

Percona is glad to announce the release of Percona XtraDB Cluster on January 30th, 2013. Binaries are available from downloads area or from our software repositories.

Bugs fixed:

• In some cases when node is recovered variable threads_running would become huge. Bug fixed #1040108 (Teemu Ollakka).
• Variable wsrep_defaults_file would be set up to the value in the last configuration file read. Bug fixed by keeping the value found in the top configuration file. Bug fixed …

My Mozilla coworkers Ben Kero and Dan Maher gave a standing-room only presentation at Linux Conf AU about “How to Use Puppet Like an Adult”. It was fantastic!

Data != logic
Business DATA does not belong in modules, but business LOGIC is OK.

What are the data sources, then?
Hiera – lightweight pluggable, hierarchical databases. External to the modules, you can use many backends, including MySQL. New feature, standard in puppet 3.0. If you like YAML (and you should), you’ll like this.

$var = lookup('something') # unscoped (complicated)
$var = lookup('namespace::something') # scoped (yay!)

Another data source is puppetdb. This is a bigger topic, but the important thing is that it can be used for high performance store configs.

Where to find pre-built modules for puppet?
…

This is not quite a liveblog, but a set of notes about the points I found most interesting in this morning’s Linux Conf AU keynote, given by Dr. Andrew “bunnie” Huang, best known for Hacking the Xbox and developing the chumby.

The talk was a fascinating look at how complex developing embedded Linux devices is. Let’s start with the takeaways:

One of the points bunnie made was that customizing embedded devices is really a frontier at this point (though he did not use the word “frontier”). There are not a lot of folks doing it. The “Sustainability” bullet point emphasizes this – bunnie talked about how people create custom environments for the device and want updates pushed to it, but that’s difficult because the environment may mean special tweaks to the updates.

The cost point was interesting …

Sheeri wrote a blog post that claims that “IN Subqueries in MySQL 5.6 Are Optimized Away” and uses that as a basis to conclude that subquery optimizations in MySQL 5.6 are superior to MariaDB’s.
The claim is incorrect (and so is the conclusion). As a person who has coded both of the mentioned FirstMatch and semi-join materialization, I think I need to write about this.

Sheeri wrote:

1. “So MariaDB recognizes the subquery and optimizes it. But it is still optimized as a subquery”
2. “In MySQL 5.6, the subquery is actually optimized away”

The first statement is somewhat true. The second one is not. …

Standard MySQL is configurable such that a single master server can be clustered with a number of read-only slave servers. To enable this master-slave replication, master’s transaction logs are communicated to the slaves (log shipping). Log shipping is a form of asynchronous replication. Under this configuration, the data on the slave always remains behind the master, a condition referred to as slave lag or replication lag. The extent of the slave lag depends on workload, network bandwidth and network latency. Database reads can be served out of the slaves, assuming the application has been designed to tolerate the slave lag and requisite staleness of data (eventual consistency), which can at times be variable and opaque. MySQL master-slave replication offers the possibility of promoting a slave to become the new master should the master fail, but this is very painful to do in practice. The cluster has to stop taking ANY writes while it waits for …

MySQL Users Group, please let us know you schedule so we can help promote your events. And if you are interested in starting a MySQL — let us know as we can help.

The MySQL Community Team wants to make sure you do not miss out on upcoming shows.

Fosdem is this coming weekend and there will be a MySQL and Friends devroom. This show in Brussels features presentations from Lars Thalmann, Sveta Smirnova, Luis Soares, Giuseppe Maxia, Øystein Grøvlen, and many more.

MySQL is a sponsor of the SunShine PHP and Ligaya Trumelle will be presenting on MySQL.

The Rocky Mountian orage Users Group will hold their training days February 11th through the 13th with a very interesting …

Actian acquires Pervasive. ObjectRocket has liftoff. And more.

For 451 Research clients: Actian’s persistence pays off as Pervasive agrees to $162m acquisition bit.ly/WPiGiS

— Matt Aslett (@maslett) January 30, 2013

For 451 Research clients: ObjectRocket has liftoff for MongoDB database as a service bit.ly/WuqF6R

— Matt Aslett (@maslett) January 29, 2013

Pervasive Software Inc. Enters Into Agreement to be Acquired by Actian Corporation bit.ly/TQ3J3t

— Matt Aslett (@maslett) January 29, …

New GreenSQL 2.3 Version Strengthens Underlying Database Security Technology While Further Simplifying User Experience

GreenSQL new version is easier to configure and manage locally and on the cloud

The newest version of GreenSQL, 2.3, makes it even simpler to secure databases with its streamlined configuration and Amazon cloud compatibility.

GreenSQL provides unified database security protection against SQL injection attacks and other internal and external threats via database activity monitoring, real-time dynamic data masking, and database security.

• Version 2.3’s database security policy automatically detects SQL injection attempts. To ease administration, it automatically detects both the operating environment and database session identifiers (user, database, source IP, and application). By pushing activity monitoring logs …