Have you ever had a question about Innodb internal design or behavior which is not well covered in MySQL manual ? I surely had.
Now you have a great chance to have them answered !

Heikki Tuuri, Creator of Innodb will answer your Questions about Innodb at MySQL Performance Blog.

Please leave your questions as comments to this post by 5th of October and I will pass them to Heikki to reply merging with questions I have myself.

Note: due to Oracle policies Heikki will likely be unable to answer your questions about Innodb new features or timetables.

Entry posted by peter | 44 comments

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Keith Murphy has published the 64th edition of Log Buffer, the weekly review of database blogs, on Diamond Notes. Frank Wiles is standing by to do LB#65 next week on his Revolution Systems Blog. Everyone’s doing it, and you can too! Read the Log Buffer guidelines and send me, the LB coordinator, a note [...]

Many Open Source software solutions use database per user (or set of tables per user) which starts to cause problems if it is used on massive scale (blog hosting, forum hosting etc), resulting of hundreds of thousands if not millions of tables per server which can become really inefficient.

It is especially inefficient with Innodb tables both in terms of space (some tables would keep only couple of small rows, but require at least 16K page in Innodb), keeping all tables open in Innodb dictionary and number of other challenges in IO management and recovery. For MyISAM it works better but still overhead can get significant because table_cache can't be made large enough and so a lot of table reopens needs to happen which requires table header modification, which is costly.

Of course if you can simply rewrite software to store multiple users per table it is best way to go, however quite typically this is way too much …

DRBD 8.2.0, released today, includes a much requested new feature, embodied in the new data-integrity-alg configuration option: DRBD protocol level data integrity checksums.

A few months ago, some users alerted us to DRBD replication issues where DRBD supposedly “ate their data”, i.e. corrupted replicated data in transit. Eventually we traced those problems not to DRBD errors, but in fact to network drivers messing up TCP checksums or segmentation. Typically this was related to using either TCP segmentation offloading (TSO) or TCP checksum offloading. However, at the time DRBD had no way of detecting these errors — you would only find out if you switched over to your Secondary, only to find your data not having been replicated properly.

With DRBD 8.2.0, you can check the integrity of replicated data in transit. To that end, …

First, I’d like to thank everyone who’s downloading and testing the latest MySQL 6.0 Alpha release that contains our new Falcon transaction storage engine. For those of you who haven’t yet, let me point out something you may have missed (heck, maybe those of you who’ve already downloaded 6.0 have missed it too…) - the latest release contains the first cut of Falcon tablespaces. We get requests all the time that storage engines support the concept of tablespaces, and with Falcon, you’ve got them now. You can create user-defined tablespaces via DDL, assign your tables/indexes to whichever tablespaces you want via CREATE TABLE, and move objects to different tablespaces with simple ALTER TABLE commands.

I’ve written a quick primer on Falcon tablespaces that will help get you started, so check that out and then …

It always surprised me how little Innodb team seems to think about product usability/ease of use, when it comes to settings, performance management etc.

I could understand many things 5 years ago, like a lot of information being available only in hard to parse SHOW INNODB STATUS output or even uglier hacks with creating tables such as innodb_lock_monitor to get more detailed information free space specified in table comments (which need to be parsed) etc. 5 years ago Heikki was along and he had a lot to do to make things work well so a lot of these things were just done quick and dirty way.

It is however hard for me to understand why so many years later with significantly increased team not only many of these things remain unfixed but things are still done similar way ?

Other the years variables like innodb_thread_concurrency were added with rather complicated history of …

There will be two MySQL representatives on the fifth jubilee edition of OpenFest in Sofia. Yes, there will be MySQL representatives for fifth time in a row

The lecture, which will be most interesting for me is the one about MySQL proxy. Andrey gave us a general vision on the subject a few months ago during the WebTech, and now I hope that Giuseppe Maxia will tell us some more details about it and that he will be ready to answer many questions; we are planning to give him some “hard time” since he is coming here.

The other lecturer will be Domas Mituzas. He is also a MySQL representative, but he will tell more about the creation of Wikipedia, because …

This week aside from tons of different tasks I was working on one of MMM users complaint regarding some issues with MMM on Solaris 10. I knew that this OS has not so user (admin) friendly environment (especially for people with strong GNU-related background), but had no other options and decided to install Solaris 10 in VMWare Fusion on my desktop.

Installation was a bit strange comparing to Debian/RHEL/Ubuntu and FreeBSD where I have a strong experience, but I’ve managed to install it successfully. The major problem after my first boot was a lack of knowledge about how things could be done in Solaris… Below I’ll describe what generic Linux admin could do with Solaris to make it easier to use and more friendly for GNU-addicted mind

Notice: If you’re …

Last week was the MySQL developers meeting. Since MySQL is a virtual company, I don't get a chance for direct feedback all that often from a room full of developers.

I ended giving three University sessions during the week. The only new one was on MySQL Slap (the rest of my talks were on Storage Engines and plugins). You can find the presentation here:
http://forge.mysql.com/w/images/8/82/Mysqlslap.pdf

The presentation is just a bunch of bullet notes, I am told that they taped it and that a video will be coming out shortly (do not miss the one where I broke the glass mid session!).

BrianM had asked me a while ago about adding support to run multiple tests at the same time. This is what I have figured out so far:


./mysqlslap --only-print --concurrency=5 --iterations=1 --number-int-cols=2 …

Many web developers view development of C programs as a bit of a black art. Development of programs in a compiled language such as C is vastly different from the development of applications in a scripting language. To familiarize more developers with the MySQL C API, we present a three-part series of articles tailored to developers looking to get into C program development with MySQL. This first article is the full chapter from Paul DuBois' industry-standard work, MySQL, Third Edition, from Pearson Publishers. The second article, from Mark Schoonover, to be published next week, will cover development with the C API using the Eclipse CDT to write a sample program. The third article, also from Mark Schoonover, will go into more depth and expand the example program using more advanced features of the API.