The other day I was working on an issue where one of the slaves was showing unexpected lag. Interestingly with only the IO thread running the slave was doing significantly more IO as compared to the rate at which the IO thread was fetching the binary log events from the master.

I found this out by polling the SLAVE STATUS and monitoring the value of Read_Master_Log_Pos as it changed over time. Then compared it to the actual IO being done by the server using the pt-diskstats tool from the excellent Percona Toolkit. Note that, when doing this analysis, I had already stopped the slave SQL thread and made sure that there were no dirty InnoDB pages, otherwise my analysis would have …

MySQL is the little engine that could. It powers sites like Facebook, YouTube, Twitter, and thousands of blogs, CMSes, and e-commerce sites. Its value to the world and to the development community could be measured in the hundreds of billions, and yet it’s free, and you can use it just by downloading it. Almost every programming language has drivers for it and it can run on so many operating systems and architectures, there’s really no limit on it.

Yet there’s a dark side. MySQL is full of gotchas and bugs, and it lacks features that sometimes call into question its status as a real database. The documentation is often open-ended and confusing, with gaps in key parts. If you want to run it, you have the option of using it on Linux, Mac, Solaris, or Windows and every hosting company or provider like Amazon AWS has their own managed service, each with its own quirks and limitations. The user community has also produced thousands of …

The availability of the node.js binding for MariaDB’s non-blocking client library together with the GIS capabilities of MariaDB inspired me to make an example of using node.js and MariaDB to import so-called GPX tracks to a MariaDB database and then show them on a map. GPX tracks are what are stored by many GPS devices including running watches and smartphones.

My project makes use of MariaDB’s non-blocking client library together with the node.js platform and on top of that uses the GIS functionality found in MariaDB 5.5 and 10.0.

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The OpenBSD Foundation is raising funds - they’ve got a goal of USD$150,000 (so far they’ve achieved $100,000). A few days ago they had potential trouble keeping the lights on for this secure BSD distribution, and today they’re all set in terms of electricity to power servers and looking for more around project expansion. 

If you dig MariaDB, it’s worth noting that MySQL 5.1.73 ships and the MariaDB branch in the ports tree is currently at MariaDB 10.0.7. Previously they shipped MariaDB 5.5.

Donate to keep the lights on for …

The availability of the node.js binding for MariaDB’s non-blocking client library together with the GIS capabilities of MariaDB inspired me to make an example of using node.js and MariaDB to import so-called GPX tracks to a MariaDB database and then show them on a map. GPX tracks are what are stored by many GPS devices including running watches and smartphones.

My project makes use of MariaDB’s non-blocking client library together with the node.js platform and on top of that uses the GIS functionality found in MariaDB 5.5 and 10.0.

To start with let’s go through the software and components I’m using:

• Node.js – The popular Node.js platform built on Chrome’s JavaScript runtime. An event-driven and …

FOSDEM happens this year, February 1&2 2014. This year is a special year as it is the 10th anniversary: great content in the schedule, you must pre-register for dinner (lot’s of wonderful Belgian food & drink), and we have a shared booth in the expo hall.

Read more about the event with a wonderful post by Kenny. Again, much thanks to Liz, dim0, Kenny, Frederic for organising the venue, and the sponsors Oracle/SkySQL/Percona.

…

I’m back home in Toronto, after having spent part of last week in Washington DC meeting Oracle’s Federal MySQL users.

I think generally speaking when you look at buzzwords in the startup scene, there is a filter as to what bubbles up into the more conservative enterprise and public sector.

My impression was that there is some interest in big-data, but there is absolutely phenomenal interest in cloud computing. This was a real take away for me, and next time I plan to talk more about the MySQL utilities and MySQL Fabric.

There were two side discussions that affected a number of users that I wanted to follow up with here:

• When upgrading from MySQL 5.5 to 5.6, secure-auth is enabled by default. This incompatible change is unfortunate, but was required to improve MySQL’s password hashing strength. My …

Over the last few days, I integrated the MySQL 5.6 GTID version of the Percona Replication Manager (PRM) work of Frédéric Descamps, a colleague at Percona. The agent supports the GTID replication mode of MySQL 5.6 and if the master suffers a hard crash, it picks the slave having applied the highest transaction ID from the dead master. Given the nature of GTID-based replication, that causes all the other slaves to resync appropriately to their new master which is pretty cool and must yet be matched by the regular PRM agent.

For now, it is part of a separate agent, mysql_prm56, which may be integrated with the regular agent in the future. To use it, download the agent with the link above, the pacemaker configuration is similar to the one of the regular PRM agent. If you start from scratch, have a look …

Continuing my investigation of single-threaded performance in the MariaDB server, I managed to increase throughput of single-threaded read-only sysbench by more than 40% so far:

I use read-only sysbench 0.4.12 run like this:

    sysbench --num-threads=1 --test=oltp --oltp-test-mode=simple --oltp-read-only --oltp-skip-trx run

And mysqld is run with minimal options:

    sql/mysqld --no-defaults --basedir=X --datadir=Y --innodb-buffer-pool-size=128M

With modern high-performance CPUs, it is necessary to do detailed measurements using the built-in performance counters in order to get any kind of understanding of how an application performs and what the bottlenecks are. Forget about looking at the code and counting instructions or cycles as we did in the old days. It no longer works, not even to within an order of magnitude.

This year we have a dedicated track for MySQL at the Oracle User Group event in Norway.
This event is scheduled between 3rd of April and 5th of April.

We have 7 great session on MySQL at the event:

• Next generation MySQL: News in MySQL 5.7
• MySQL and NoSQL: Best of both worlds
• Introduction to MySQL Database Development with MySQL Workbench
• Quick Dive into MySQL
• How are queries optimized? An introduction to the optimizer
• MySQL Replication and MySQL Utilities – including demo!
• MySQL EXPLAIN Explained

See full agenda here: http://ougnvarseminar2014.sched.org/overview/type/mysql#

Registrer here: …