When we started to develop Galera replication about 5 years ago, we faced a question of how to test it under load: we needed a fast, flexible and easy to use load balancer. Thus GLB project was born, explained in my "How Hard Could That Be?" old blog post (lost in site upgrade, but miraculously preserved by Wayback Machine).

It turned out that it was not that hard at all — it was unsurmountable. Linux splice() function turned out to be a joke and you still had to do at least 3 system calls per packet: (e)poll(), read(), write() - 6 per SQL request. And that's a lot of CPU. And a lot of latency.

And while it is not that much faster than pen or haproxy (insignificantly so for production purposes), glbd IS the fastest …

Over the past few months I have been spending my spare time on a new project.  A new version of libdrizzle which is much simpler to use and with many new features.  Today the first version of this MySQL compatible client is released, called Libdrizzle Redux.

Why 5.0?  Because Libdrizzle 1.0 and 2.0 have already been released, in packaging versions 3.0 and 4.0 used as API revisions.  So 5.0 is the fresh start.

Main FeaturesThese are the main features of the library:

• A BSD licensed MySQL compatible C connector, so you can statically link it with commercial software
• A simplified API compared to Libdrizzle.  No more confusion over whether the client or library should be allocating/freeing.  There isn't a big difference to the MySQL C API for most things.
• New documentation, PDF for now web based coming soon.
• A new binlog …

There was one MySQL server with a Adaptec Raid controller and 4 disks. One of the disks was having media errors and caused the whole SCSI bus to become unavailable.

This resulted in a corrupted InnoDB table.

Luckily we did have backups. A full backup and incrementals.

So to restore the backups I installed XtraBackup and MySQL 5.5 on another server.

Then the first step was to 'prepare' the backup. This worked okay for the full backup (redo only).

The second step to add the incremantals failed for the first incremental. This was easily resolved by specifying the full paths instead of relative paths.

Then the backup was fully prepared using the redo logs and undo logs.

As XtraBackup doesn't backup your my.cnf we copied the my.cnf from another server and adjusted it for this server. The my.cnf in your backup only contains everything needed for a …

its very easy learning step by step for the beginners

Taxonomy upgrade extras: innodb

In this weeks MySQL workshop we were discussing, beside other things, about the innodb_file_per_table parameter and its advantages of enabling it. In addition there was a discussion if the InnoDB system tablespace file can be shrinked once it has been grown very large or not. We all know the answer: The InnoDB system tablespace file does never shrink again.

But why should it not be possible? Other databases like for example Oracle can shrink or even get rid of tablespace files... After some philosophising about it we came to the conclusion that we should give it a try if this is possible with InnoDB as well.

The scenario we considered was the following: You inherit a MySQL database with InnoDB tables but innodb_file_per_table was set to 0. So all the tables are located in the InnoDB …

Percona is glad to announce the release of Percona Server 5.5.28-29.2 on December 7th, 2012 (Downloads are available here and from the Percona Software Repositories).

Based on MySQL 5.5.28, including all the bug fixes in it, Percona Server 5.5.28-29.2 is now the current stable release in the 5.5 series. All of Percona‘s software is open-source and free, all the details of the release can be found in the 5.5.28-29.2 milestone at Launchpad.

New Features:

• Multiple …

Percona Live UK took place this week. It was the second year in a row and once again a great conference. Thank you Percona for bringing the show to Europe, it means a lot for the European MySQL community - many people who don't visit the Santa Clara conference were present in London. It's kind of funny, I even meet more Finnish MySQL users in London than I do at home!

I gave 2 talks. Slides are now posted on Slideshare:

read more

Fetching data from a database to then get it into an Excel spreadsheet to do analysis, reporting, transforming, sharing, etc. is a very common task among users. This task can be accomplished in several different ways and with different tools getting the same result; but users may find the process rather complicated, too technical and lengthy. With MySQL for Excel the task of importing data from a MySQL database to an Excel spreadsheet becomes an easy one and accessible to all types of users.  Here is a quick guide describing how to import data to Excel using MySQL for Excel.

I have been a member of Oracle since April 2011. I am forever grateful to Oracle and the MySQL Team for allowing me to join and work on their behalf.  Oracle has been very supportive of MySQL and I look forward to their continued advancements with MySQL.  I have also traveled all over the United States meeting and talking with members of the MySQL community and it has been wonderful.  Thank you to everyone who stopped by and talked or attended, not only my sessions, but all of the MySQL sessions at conferences.

I do enjoy supporting MySQL and I will be continue to blog and speak at events whenever I am able too. I will however be moving on. Since people will ask, I am going to be joining the "independently spirited and fiercely unconventional" …

It’s always sunny in the database arena, even if the data is engulfed in the clouds. Innovation rays keep databases illuminating and bloggers make hay in this sunshine and this Log Buffer Edition sift through all those blog post and brings you Log Buffer #298. Oracle: When Michael Abbey writes it, it stays written. His...