In my work on group commit for MariaDB, I have the following situation:

A group of threads are going to participate in group commit. This means that one of the threads, called the group leader, will run an fsync() for all of them, while the other threads wait. Once the group leader is done, it needs to wake up all of the other threads.

The obvious way to do this is to have the group leader call pthread_cond_broadcast() on a condition that the other threads are waiting for with pthread_cond_wait():

  bool wakeup= false;
  pthread_cond_t wakeup_cond;
  pthread_mutex_t wakeup_mutex

Waiter:

  pthread_mutex_lock(&wakeup_mutex);
  while (!wakeup)
    pthread_cond_wait(&wakeup_cond, &wakeup_mutex);
  pthread_mutex_unlock(&wakeup_mutex);
  // Continue processing after group commit …

In my work on group commit for MariaDB, I have the following situation:

A group of threads are going to participate in group commit. This means that one of the threads, called the group leader, will run an fsync() for all of them, while the other threads wait. Once the group leader is done, it needs to wake up all of the other threads.

The obvious way to do this is to have the group leader call pthread_cond_broadcast() on a condition that the other threads are waiting for with pthread_cond_wait():

  bool wakeup= false;
  pthread_cond_t wakeup_cond;
  pthread_mutex_t wakeup_mutex

Waiter:

  pthread_mutex_lock(&wakeup_mutex);
  while (!wakeup)
    pthread_cond_wait(&wakeup_cond, &wakeup_mutex);
  pthread_mutex_unlock(&wakeup_mutex);
  // Continue processing after group commit …

Just in case it wasn't clear from Hakan's post, we are opening up the next Monty Program company meeting in October 7-12 to be a general MariaDB developers meeting. (In fact, we've had a few guests in all of the previous meetings too, but now it's formal and public.) Ever since Sun folded this annual MySQL AB tradition (to save money) there has been people asking when the next meeting would be, since for the developer community outside MySQL AB it was the main networking and information sharing event of the year. Last MySQL user conference we agreed that something needs to be done, and this is it. If you work on any of the MySQL variants, a storage engine, or are otherwise interested in deep architectural MySQL/MariaDB discussions, you are welcome to join and should contact Hakan or My for details. …

Open Query now has its own @openquery account on Twitter and Identi.ca so you can conveniently follow us there for announcements and tips – and also ask us questions! All OQ engineers can post/reply. The OQ site front page also tracks this feed.

Previously I was posting from my personal @arjenlentz account with #openquery hashtag, but that’s obviously less practical.

I'm in the process of setting up Redmine (version 1.0-stable) on an Ubuntu 8.04 virtual machine. Getting a recent enough gem and rails is less fun than you might imagine, but the big issue I came across was a bug in the database model, which makes MySQL 5.1 (MariaDB 5.1 in my case) barf on installation.

There is a fix, but I am running from a git clone didn't want to download and apply a diff file to that repository. A quick google found what I need: the git cherry-pick command. It allows you to grab a single commit and apply its changes to your branch. In my case:

git cherry-pick  …

You take a look at someone’s MySQL (or MariaDB) data directory, and see

mysql
foo
bar -> foo

1. What’s the issue? Identify pattern.
2. What does it mean?  Consequences.
3. Is there any way it can be safe and useful/usable? Describe.

Good luck!

Tokutek tests its TokuDB Fractal Tree storage engine with multiple MySQL distributions. We make extensive use of the MySQL Sandbox in our test automation. We tweaked the regular expressions that match binary tarball names in the MySQL Sandbox so that MariaDB releases can be easily loaded by the MySQL Sandbox. These changes can be found in launchpad lp:~prohaska7/mysql-sandbox/mariadb.

So I sometimes get asked if we funnel back bug reports or patches back to MySQL from Drizzle. Also, MariaDB adds some interest here as they are a lot closer (and indeed compatible with) to MySQL. With Drizzle, we have deviated really quite heavily from the MySQL codebase. There are still some common areas, but they’re getting rarer (especially to just directly apply a patch).

Back in June 2009, while working on Drizzle at Sun, I found a bug that I knew would affect both. The patch would even directly apply (well… close, but I made one anyway).

So the typical process of me filing a MySQL bug these days is:

• Stewart files bug
• In the next window of Sveta being awake, it’s verified.

…

I`m not the biggest fan of openSUSE but this weeks post by Colin Charles makes me happy ..

openSUSE users can now do a mariadb install from their default repositories.

With all the fuzz about Snoracle and MySQL's future last year to me it became clear that we would end up having different MySQL based distributions, probably with different names, and that it would be up to the Linux distributions to provide the users with what they preferred, working with those Linux distributions
therefore would be very important for the MySQL distributions.

Sadly my Fedora box doesn't allow me to do a yum install mariadb yet ... but I`m sure that's only a matter of time ..

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We’re at OSCON and today has been fabulous – I’ve just been connecting with old friends, and making new friends, and all this is what makes the travel experience completely worthwhile. If you’re at OSCON, why not come to a couple of BoF’s:

1. MariaDB: The Community Fork of MySQL at 8pm on Monday 19/07/2010. Great for a general overview of MariaDB, for beginners to the advanced folk to come to.
2. MariaDB: Features In-depth at 9pm on Wednesday 21/07/2010. Great if you’re a more intermediate to advanced user of MySQL/MariaDB and want to know more about the additional features MariaDB has to offer, and what else it might offer in the near future (i.e. what are you …