One major problem in terms of MySQL performance that still stands in the way of InnoDB scalability is the trx_list scan on consistent read view creation. It was originally reported as a part of MySQL bug #49169 and can be described as follows. Whenever a connection wants to create a consistent read, it has to make a snapshot of the transaction states to determine which transactions are seen in the view later. To this end, InnoDB scans trx_list (i.e. the list of currently open transactions) and copies IDs of transactions that have not yet been committed at the current point in time, and thus should not be visible in the consistent read. For the REPEATABLE_READ isolation level, the snapshot is created on the first SELECT …

I enabled the InnoDB Lock Monitor in my MariaDB 5.5 instance (using XtraDB+ as the InnoDB – which is the default in MariaDB) and noticed that while the SHOW ENGINE INNODB STATUS was being logged to the error log, it wasn’t logging the “additional” lock information – it just looked like the plain ‘ole INNODB STATUS.

Long story short, Percona added a new variable so one has better control over what gets logged:

innodb_show_verbose_locks

If off (default), then the InnoDB Lock Monitor logs the normal INNODB STATUS, and if enabled, then it logs it with the extended lock information.

They also created another variable that goes along with this one (and the InnoDB Lock Monitor), which is:

innodb_show_locks_held

This variable indicates the number of locks to print that are held …

I actually don’t remember exactly whether it was in 2006, 2007 or 2008 — but around that time the MySQL community had one of the greatest MySQL conferences put on by O’Reilly and MySQL. It was a good, stable, predictable time.

Shortly thereafter, the MySQL world saw acquisitions, forks, times of uncertainly, more acquisitions, more forks, rumors (“Oracle is going to kill MySQL and the whole Internet”) and just a lot of drama and politics.

And now, after all this time some 6 or 7 years later, it feels like a MySQL Renaissance. All of the major MySQL players are coming to the Percona Live MySQL Conference and Expo 2013. I am happy to see Oracle’s engineers coming with talks — and now with a great MySQL 5.6 release — and I have great …

For this post I’m going to shamelessly exploit the litany of technical problems SimCity players encountered earlier this month and a few examples of how Thread Pool for MySQL and Percona Server for MySQL can help to prevent such incidents.

Users of SimCity, a city-building and urban planning simulation video game, encountered network outages, issues with saving progress and problems connecting to the game’s servers following a new release a couple of weeks ago featuring a new engine allowing for more detailed simulation than previous games. During this same time, we happened to be testing the Thread Pool feature in Percona Server for MySQL, and I saw a connection of how Thread Pool is supposed to help in such cases.

Basically SimCity users faced the same situation …

Percona’s Kenny Gryp leads a recent MySQL workshop

Percona will be in Chicago and London the week of April 8th delivering two 2-day MySQL workshops. For our MPB readers, we are offering a 15% discount. Just use MPB15A when purchasing your tickets to one or both MySQL workshops.

• Scaling and Optimization for MySQL on Monday & Tuesday, April 8 & 9
  • This MySQL workshop will cover:
    • Apply architecture scaling strategies that make the most sense, including …

Percona Server for MySQL version 5.6.10-60.2

Percona is glad to announce the release of Percona Server for MySQL 5.6.10-60.2 on March 14, 2013.  (Downloads are available here and from the experimental Percona Software Repositories). Based on MySQL 5.6.10, including all the bug fixes in it, Percona Server 5.6.10-60.2 is the third ALPHA release in the Percona Server 5.6 series. All of Percona‘s …

Percona Server for MySQL version 5.1.67-14.4

Percona is glad to announce the release of Percona Server for MySQL version 5.1.67-14.4 on March 8, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.67, including all the bug fixes in it, Percona Server 5.1.67-14.4 is now the current stable release in the 5.1 series. All of Percona‘s software is open-source and free, all the details of the release can be …

Percona Server on the Nexus 7: Your own MySQL Database Server on an Android Tablet

Following Roel’s post, Percona Server on the Raspberry Pi: Your own MySQL Database Server , I thought what other crazy gadget can I run Percona Server on? And having an Asus Nexus 7 Android tablet I decided to give it a try.

Anything below contains a risk that you break your tablet if you do not know what you are doing, so be advised.

First, we need rooted tablet, most likely with custom ROM. I personally use …

Percona Server Wins Developer Week 2013 Award; Named Top Innovator in SQL Technologies Category

Percona Server has won a 2013 DeveloperWeek Best of Tech award, being named Top Innovator in the SQL Technologies category!

We’re proud to accept this award, which is determined by a combination of peer voting and review from an independent panel of judges. Thank you to everyone who voted for Percona Server!

From our press release: According to a 451 Research report titled, “MySQL vs. NoSQL and NewSQL: 2011-2015,” Percona …

MySQL MHA by Oracle ACE Director Yoshinori Matsunobu is an excellent open source tool to help in providing HA with native MySQL replication. The installation however is dependent on some Perl packages and to the untrained eye this may be an issue if you are using Percona Server as your choice of MySQL implementation.

The MHA Node page requires the perl-DBD-MySQL package to be installed. The installation on RedHat/CentOS/Oracle Linux look like this:

$ sudo yum install perl-DBD-MySQL
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirror.anl.gov
* extras: mirror.anl.gov
* updates: mirror.anl.gov
Setting up Install Process
Resolving Dependencies
--> Running transaction check …