There has been some great discussion lately about internal database schedulers and I/O handling on the Drizzle mailing list, and I thought I’d blog about it to summarize and see what others thought. These are ideas we’re toying around with for Drizzle, but they could be interesting for other databases (or other types of servers). The key things we are focusing on are modularity and concurrency. We also need well defined interfaces to allow anyone to come along and write/rewrite a component for their own needs.

History

First, a little background for those not familiar with Drizzle or MySQL internals. In MySQL, a client is accepted, assigned to a THD (thread) object, and is given an actual thread to run in. The client basically sits in a loop of reading a command, parsing it, executing it, and writing the result back. This works fine when …

So the cat is out of the bag,

As of today Inuits is rebranding to Pinuits,
The press release is here

We've had good feedback on the new name so far. Different people told me the name matched better to what we are doing . Actually my wife thinks our new name is much better as at least the Pin in Pinuits refers to our favourite Tux again ..

Finding an appropriate name for an Open Source consultancy company, with focus on Linux, Open Source Monitoring, MySQL, Open Source Virtualization , Large Scale Deployments , High Availability and Drupal, isn't easy .. you want to show both community involvement and professionality. And find a domain that's still available.

Technorati Tags: apache drupal …

I’ve not looked at compiling and running Drizzle on my server for the past four weeks. Well overdue time for a check and see how it’s going. I saw in today’s planet.mysql.com by Eric Day a new dependency is needed. libdrizzle 0.2.0 now in Drizzle is now required, so I started there.

cd ~/bzr
bzr branch lp:libdrizzle
cd libdrizzle
./config/autorun.sh
./configure
make
sudo make install

No problems there, also documented at the Drizzle Wiki. Great to see the docs up to date. I see my old work on starting the compiling page still relevant. Tested on CentOS 5 and Mac OS/X 10.5

Compiling drizzle was not much more difficult.

cd ~/bzr/drizzle
bzr update
make distclean
./config/autorun.sh
./configure --prefix=/home/drizzle/deploy …

Developments seem to be accelerating, here’s anecdotal evidence.

Foreign Keys
The Foreign Keys (all engines) worklog task passed another milestone last week: now MySQL is doing referential constraint checks at end of statement when the standard so prescribes, rather than row-by-row. This means that the all-engines functionality is now slightly greater than what’s in MySQL’s current InnoDB-only foreign-key handling.

The closing of Bug#989
“The wheels of the gods grind slowly, but they grind exceedingly fine.” Our Bordeaux-area Maria expert Guilhem Bichot reported Bug#989 “If DROP TABLE while there’s an active transaction, wrong binlog order” in August 2003 and some unkind soul even mentioned it on the wikipedia article about MySQL. The mention is gone now. And so …

It is all about one bug fix, one little feature, one step at a time.

Armin Schöffmann fixed a bug (Deadlock in mysql_real_query with shared memory connections, is what Armin calls it), Armin signed the Sun Contributor Agreement (24 March 2009), Vladislav Vaintroub and Davi Arnaut reviewed, committed and queued the patch to MySQL 5.0 bug team (26 and 27th of March, 2009).

That's a great example of open, contribution-based MySQL development with real results.

Thank you Armin!

Thank you Vlad!

Thank you Chad!

Thank you Davi!

Thank you ... the one whose name I've left out! (Feel free to leave a comment below.)

It is all about one bug fix, one little feature, one step at a time.

Armin Schöffmann fixed a bug (Deadlock in mysql_real_query with shared memory connections, is what Armin calls it), Armin signed the Sun Contributor Agreement (24 March 2009), Vladislav Vaintroub and Davi Arnaut reviewed, committed and queued the patch to MySQL 5.0 bug team (26 and 27th of March, 2009).

That's a great example of open, contribution-based MySQL development with real results.

Thank you Armin!

Thank you Vlad!

Thank you Chad!

Thank you Davi!

Thank you ... the one whose name I've left out! (Feel free to leave a comment below.)

Taking the work already done with vmplot.sh, a useful tool for MySQL performance tuning by Yves and Matt at BigDBAHead, and in true Open Source fashion I’ve enhanced and modified for my own purposes.

These changes include:

• Error checking for ‘gnuplot’ command on the system
• Eliminate the first row of sample data, as this is often not a complete sample for the vmstat duration.
• Created a HTML output file for easy browser viewing
• Changed Memory scale values from Kilobytes to Megabytes
• Resizing png’s for optimal 1024×768 display output (2 per row)

Download vmplot

And I get:

So more specifics of what I did.

Install gnuplot.

$ yum install gnuplot

Create vmstat sample …

Community strikes.
It was about time that someone provided a match for MySQL Query Analyzer, the flagship feature of MySQL Enterprise.
Now MySQL Sandbox includes a --query_analyzer option, which will convert your sandboxed server into an analysis machine. No need to buy Enterprise. No need to waste tons of money on expensive consultants.
Just download the latest tarball and install a sandbox as usual, with the additional option.

$ make_sandbox 5.1.32 --query_analyzer 

And that's it! Your worries will be over. Enjoy!

Update As it should be clear by now, this was an April's fool joke. See the follow up …

The UC is closing in fast and there are a number of (potentially) interesting talks around MySQL Cluster.
Personally, I will give two talks (sessions):

• MySQL Cluster 6.4 (7.0) - New Features
  I will talk about ONLINE ADD NODE, and multithreaded data node, and the rest of the things that are new in 7.0. Please note that MySQL Cluster 6.4 changed name to 7.0, but the session title didn't.
  When and Where: Ballroom A at 05:15pm, Tuesday, 04/21/2009
• LDAP for MySQL Cluster- back-ndb
  Together with Howard Chu, CTO of Symas, we will present OpenLDAP for MySQL Cluster. Check out this …

I’ve spent the past couple weeks ripping out the old client library (based on libmysql) from the Drizzle client utilities (drizzle, drizzledump, drizzleadmin, …). I’ve replaced it with new code that uses the new libdrizzle. Brian merged this patch into the trunk yesterday, so we are one step closer to being rid of the old library! It is still used internally within the server, so my next task is ripping it out from there.

This means that the old library is no longer installed, so all new client and application development needs to use the new libdrizzle. It also means libdrizzle is now required to be able to build Drizzle. While I’ve done my best to convert the old utilities, I’m sure I’ve missed a few things. Please report any bugs you find with them. …