Colin Charles Agenda

MariaDB has plenty of mirrors to download the latest versions of MariaDB. Typically mirrors carry the last couple of releases and the current release, but what if you wanted to access something much older?

You have two resources for the complete archive:

1. http://archive.mariadb.org/ – this is the official archive, but from what I gather, it can be quite slow
2. http://downloads.skysql.com/files/MariaDB/ – SkySQL provides a complete mirror and it is very fast so I would use this instead. 

Current download archives stand at 337GB. But you can feel free to test older releases, see when things got introduced, etc. 

Recently there was a discussion on the webscalesql mailing list started by Chip Turner on a proposed change to the MAX_STATEMENT_TIME patch. This feature has been known as per query variable settings (WL#681) and even shipping in Percona Server 5.6 as per-query variable statement.

This feature has piqued my interest since 2009, when the MySQL project (then owned by Sun Microsystems) participated in Google Summer of Code 2009, and we got code from Joseph Lukas to do just that (see his tree on Launchpad – lp:~jlukas79/+junk/mysql-server).

So code has been floating around since 2009. It never made it into a shipping release of any MySQL-based distribution till 24 October 2013 when Percona Server 5.6.14-62.0 was released. Percona’s syntax implementation was as suggested in WL#681. This got me curious as to if a feature is already shipping in a distribution of MySQL, what is the WebScaleSQL answer to things – is there a look at other branches or is compatibility from a user/DBA perspective only with focus on upstream?

I got my answer from Steaphan Greene. Very sensible, and a great direction to see how the companies involved can influence upstream MySQL and quite obviously the downstream distributions. It is of course great to note that this syntax improvement will probably be in MySQL 5.7.5 DMR (it already is in 5.7.4 DMR).

For what it’s worth, this feature works well alongside server-side statement timeouts, which Percona Server 5.6 implements (as an alpha quality feature) via the Twitter patch of Davi Arnaut. The MySQL team at Oracle has of course been listening, and in MySQL 5.7.4 DMR (release notes) they too have implemented this feature (WL#6936). Kudos!

Update (6 May 2014): Morgan Tocker has opened up mysql#72540.

I’ve had this question several times when presenting and once via an internal email thread so I figure I might as well write about it: What is the default transactional engine in MariaDB 10.0? The answer is simple – it is XtraDB.

However this answer has some history: initial releases of MariaDB 10 actually shipped with InnoDB from MySQL 5.6. Only in 10.0.9 RC did the default switch back to being XtraDB. As MariaDB users previously know, XtraDB was the default InnoDB in 5.1, 5.2, 5.3, and 5.5 too. As always, you can switch easily between InnoDB/XtraDB – read more in: Using InnoDB instead of XtraDB. 

How do you tell what version of InnoDB or XtraDB you are running? Simply, run: SHOW GLOBAL VARIABLES LIKE 'innodb_version';

MariaDB 10.0 (read more: What is MariaDB 10.0):

The asterisk (*) denotes the default engine choice.

Why are there odd InnoDB versions from 10.0.0 – 10.0.6? I can only point this to merge oddities. storage/innobase/include/univ.i is the file which contains common definitions such as INNODB_VERSION_MAJOR, INNODB_VERSION_MINOR and INNODB_VERSION_BUGFIX. INNODB_VERSION_BUGFIX in 10.0.6 pointed to MYSQL_VERSION_PATCH which you get from the VERSION file. For XtraDB, you will also see PERCONA_INNODB_VERSION in univ.i.

So, when XtraDB is the default (10.0.9 and 10.0.10 and releases going forward) you can put in my.cnf to load InnoDB:

ignore_builtin_innodb
plugin_load=innodb=ha_innodb.so

When InnoDB is the default (10.0.8 and 10.0.7) and XtraDB was merged, you can put in my.cnf to load XtraDB:

ignore_builtin_innodb
plugin_load=innodb=ha_xtradb.so

Percona Server only became GA with 5.6.13-61.0 which was 7 Oct 2013 which explains why the MariaDB 10.0.6 beta didn’t include a XtraDB.

Percona Server only ships XtraDB (source code in storage/innobase) while MariaDB ships both InnoDB (storage/innobase) as well as XtraDB (storage/xtradb).

If you want older release information about InnoDB plugin versions, a great resource is Chris Calendar’s blog post: InnoDB Plugin Versions. I’m just glad that going forward the InnoDB version will just match the release version as you can see with 10.0.7 and later.

Via Dave Stokes, MySQL Community Manager:

MySQL Central is truly a MySQL Community show. This year there are five tracks and the majority of the sessions in all the tracks except Performance and Scalability had many more submissions from the MySQL Community than from Oracle/MySQL.

This is impressive. There are about 200 submissions, 50 slots, a 1/4 chance of a talk getting in, and if we follow this logic we will see that MySQL Central @ OpenWorld will truly be a community event (in previous years, majority of the talks came from the MySQL team at Oracle). I can’t wait to see the final program, but as an attendee to the past two MySQL Connect events, I am looking forward to seeing this event grow and be a part of the main program (i.e. not the weekend before).

As Dave says, register now. Though I presume many will wait for the program first. Apparently it is mid-June when speakers will be notified so one can presume an agenda should be out by the end of that month.

While at the keynote of Tomas Ulin at Percona Live MySQL Conference & Expo Santa Clara 2014, he asked the audience what they were running, and most of the audience was on MySQL 5.5 while about 15% of the audience was on MySQL 5.6. This number is steadily increasing I’m sure, so one thing that becomes important is that people will probably start turning on Global Transaction Identifiers (GTIDs). 

As you may already know, MariaDB 10 has a different implementation of Global Transaction ID. To me, this poses a problem in a mixed use environment (or even a migration scenario). Which is why MDEV-4487 is so important: it is a feature request to allow replication from MySQL 5.6+ when GTID is enabled on the master. 

If you think the issue is important, you can vote and watch the issue on JIRA. I for one think this should be fixed for 10.0.11 or 10.0.12 and not wait for the 10.1 timeframe. Best not to comment here, focus on the JIRA request, MDEV-4487.

There are many MySQL related IRC discussion channels as the ecosystem itself grows. I join the following. Are there any that I’m missing?

Freenode (irc.freenode.net):

• #mysql – main channel for all kinds of end user MySQL related discussions (the noisiest of the lot, naturally)
• #maria – main channel for all kinds of MariaDB related discussions
• #webscalesql – for all kinds of WebScaleSQL discussions
• #percona – main channel for all kinds of Percona related discussions
• #tokutek – main channel for Tokutek discussions (TokuDB or TokuMX)
• SkySQL-specific channels: #maxscale and #mariadb-mgr

OFTC (irc.oftc.net):

• #debian-mysql – for all kinds of Debian MySQL related bits (packaging, bugs, etc.)