One of the things that repeatedly seem to puzzle users about the DRBD is the question of whether to use internal or external metadata. Remember, DRBD sets aside a small area on a local disk (on every cluster node) where it keeps the Activity Log, the quick-sync bitmap, data generation UUIDs, and a few other bits and pieces for local housekeeping.

The specific aspect that is to be discussed here is the Activity Log. Without going into too much detail, let’s be satisfied with the factoid that DRBD …

As someone may have noticed, I recently wrote a trilogy on how to dive into the MySQL Cluster source code. Unfortunately my overtures towards the MySQL Cluster source code ended up being only a look-but-don't-touch affair, as I failed to actually get to touch her internals with my text editor. Even so, in this post I'd like to tell about the background to my love affair with this beauty, by relating to some benchmarks I've been working on together with my customers.

Oh, and I'd like to apologize already, that I cannot mention where these benchmarks were done, what the schema looked like and the exact numbers. If you want that kind of real benchmarks, you should read Mikael's blog, or watch the slides from this …

(Continued from part II where I tried to fix a bug and found out that the affected part of the code had been rewritten, so the bug didn't exist anymore.)

Magnus gives a helpful hint...

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This is part II of my efforts to prove myself that I can do programming. In part one I successfully created a MySQL Cluster branch for myself and compiled it.

Let's go to the public MySQL bug database and see if there are any trivial MySQL Cluster bugs I could sharpen my teeth on. Heh, sure enough #32658 looks simple enough. There is a typo in an output string - so I could fix that without even doing any C++ code! (Funnily, a MySQL internal comment to the bug says something about it being embarrassing. Guess it is a good bug for me then, as patching over embarrasments is what Sales Engineers do routinely :-)

Let me see...

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My collagues Anders and even Ivan sometimes blog about the grandeur of being a Sales Engineer. And I agree, it is a great job, probably the best I ever had, so far. But let me share a secret: It's not as technical as you'd think. Sure, they call me a "pre-sales consultant" alright, but I would be ashamed of comparing my own work with those of the real consultants. I sometimes jokingly say that the most amazing technical things in my job are airplanes (they fly in the air!) and how to make a nice slideshow. (OpenOffice Impress sucks btw, and I always envy my OS X + Keynote using friends on this one point.) What I mean is, I mostly meet with customers and talk about the …

By popular demand, we are now offering an on-line incarnation of our DRBD Total training sessions, normally taught in a 4-day on-site course. The next such training commences on May 18 (next Monday), and we still have a few seats left — so if you’re interested, grab one while you still can!

What’s covered in this course?

Here is an overview of the course highlights:

• Introduction to High Availability Clustering & DRBD
• Setting up a DRBD resource and common failure scenarios
• Configuring and running the Heartbeat/Pacemaker cluster stack
• Highly available NFS, MySQL, and virtualization
• DRBD performance tuning and optimization
• DRBD integration with Red Hat Cluster Suite
• Recent and future DRBD development

Every course attendee gets a virtual cluster to play with and practice on. It doesn’t get much more hands-on than this.

After reading at a lot of places for the the single repeatative question, “What engine shall I choose – MyISAM or Innodb?”, this is what I’ve got. Following are points…

The post Choosing between MyISAM and INNODB – MySQL Storage Engines first appeared on Change Is Inevitable.

The perl script is mainly created to avoid manual Mysql Server Maintenance. The script uses Perl module DBI. You need to provide access credentials and database name(optional). Regarding Analyse, Optimize…

The post Perl Script for Analyze – Optimize – Repair Mysql Databases first appeared on Change Is Inevitable.

As part of our partnership with Dolphin Interconnect Solutions, we are presenting two webinars on DRBD for Dolphin Express on Nov. 5 (European business hours) and Nov. 12 (American business hours).

Both DRBD and Dolphin Express already being a fixture in the MySQL universe, this webinar should be particularly interesting to those of you who want to minimize database write latency while maintaining fully redundant and transaction-safe high availability. However, it’s also a must see for virtualization and mail service DRBD users, who also typically have a need for low latency.

This …

A public draft version of the all-new DRBD Users’ Guide has just been released. Feedback is more than welcome.

You may want to read the announcement as well.