With the recent media attention Volkswagen has gotten, a lot of folks are wondering, how could that happen? Aren’t there checks & balances? Join 32,000 others and follow Sean Hull on twitter @hullsean. Then I ran across this observation on Todd Hoff’s brilliant blog High Scalability Is what Volkswagen did really any different that what … Continue reading Are software benchmarks to blame for Volkswagens woes? →

I am fascinated. Maybe that should be enough, but I guess I have to write a bit more here because we are not on twitter.

I spent a few days to get know Go language, and now I am more than satisfied. I mean, all the project ideas which are floating in my head should be written in Go.

First of all, I have rewritten Mambo-collector to go (https://github.com/banyek/mambo) because I have faced some serious errors when I used it on CentOS 7 – I blame systemd -: If the process was running as root then after a few days of data collecting, killing that process was lead to restart the entire system, which is not a bug, it is a catastrophe. I tried to debug it several ways, but I am not sure where the problem is, it could be at the ‘loghandler’ redirection or any other place in python-daemon, or it is simply there is a buffer inside which overflows – I don’t really care, because mambo was just a proof of concept – what I used in …

The Severalnines team is pleased to announce the release of ClusterControl 1.2.11. 

This release contains key new features, such as support for MariaDB’s MaxScale, along with performance improvements and bug fixes. This is also our best release yet for Postgres users, as outlined below.  

Join us for a release webinar on Tuesday, October 27th 2015, during which we will discuss the new features of this release as well as demonstrate them live.

Highlights of ClusterControl 1.2.11 include:

• New for PostgreSQL
  • Deployment and Management of Postgres Replicated Setups
  • Customisable …

I’m quite pleased to announce that my pull request for Kubernetes which provides a 3-node Galera cluster for Kubernetes was merged last week. I gave a presentation at Percona Live 2015 in Santa Clara, CA back in April about this an had since modified it to use newer Kubernete’s functionality, particular now that Kubernetes services allow more than one port and Kubernetes requires several ports. Also, Skydns, which provides the ability to specify the name (vs. IP address) of each node’s service when building up the wsrep_cluster_address string as well as providing a cluster-wide service.

Tim St. Clair (Google) was quite through and very helpful in his review and the code and docuementation ended up being very complete. You can find it on Kubernetes’ source code repo:

…

Download MariaDB 5.5.46

Release Notes Changelog What is MariaDB 5.5?

MariaDB APT and YUM Repository Configuration Generator

The MariaDB project is pleased to announce the immediate availability of MariaDB 5.5.46. This is a Stable (GA) release.

See the Release …

In the spirit of sharing war stories and avoiding others to do the same mistakes as I did, here are some sequences of commands that you should avoid to run on a MariaDB slave that is lagging and which is using the GTID protocol.  Remember, do not run those because...

So, those bad commands are the following:

"STOP SLAVE; START SLAVE UNTIL ...;", or "STOP SLAVE; START SLAVE;" (to remove an

Suppose you want to send a message from one SQL session to one or more other sessions, like "Hey, session#13, here is the latest figure for your calculation, please acknowledge". I'll say what Oracle and EnterpriseDB and DB2 do, then rate the various ways to implement something similar in MySQL and MariaDB, and finish with a demo of the procedure that we use, which is available as part of an open-source package.

The syntax was established by Oracle, with EnterpriseDB and IBM following suit. The details are in the Oracle 12c manual and the DB2 9.7 manual. The oversimplification is this:

  DBMS_PIPE.PACK_MESSAGE('message');
  SET status = DBMS_PIPE.SEND_MESSAGE('channel#1');
  SET status = …

This Log Buffer Edition covers some blog posts of Oracle, SQL Server and MySQL from this past week.

Oracle:

• Oracle Utilities Application Framework V4.3.0.1.0 includes a new help engine and changes to the organization of help.
• Very simple oracle package for HTTPS and HTTP.
• Tim spotted a problem with the PDB Logging Clause.
• How to Pass Arguments to OS Shell Script from Oracle Database.

SQL Server:

• How efficient is your covered …

mysql < quarto.sql

Example game play:

mysql> -- Start the game and pass the first piece in the lower nibble
mysql> CALL SetupGame(0x0A);
-----------------------------------------------------------------------+
| rules                                                                |
-----------------------------------------------------------------------+
| Quarto: 4 in a line (row, column, or long diagonal) with at least one bit in common wins.
CALL Play(move); -- high 4 bits are board position, low 4 bits are piece for next player
CALL PrintBoard(base); -- to display the board. Useful bases are 16 and 2. |
-----------------------------------------------------------------------+

+------------------------+
| instructions           |
+------------------------+
| Player 1, play piece A |
+------------------------+

mysql> CALL Play(0x00);
+---------+
| board   | …

I presented a talk at Percona Live Amsterdam a few weeks ago (simple recipes for your Galera cluster), and one of the topics was schema changes. I discussed the drawbacks and benefits of Total Order Isolation (TOI), Rolling Schema Upgrades (RSU) and pt-online-schema-change. One thing I forgot was …