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.

DRBD 8.2.3 was released today. Even though just a micro release in terms of version numbering, it comes with a couple of very handy brand new features: on-line device verification, and tunable processor affinity.
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I’ve been asked by a number of people on how to do an upgrade from DRBD version 0.7 to DRBD 8. This upgrade does necessitate some minimal service down time, but it’s really not rocket science. And no, it does not force you to sync all of your data all over again.

Here’s my quick write-up.

An initial word of caution

Do not, I repeat do not attempt your upgrade unless you have at least read this blog entry to the finish.

Getting ready

First, you need to make sure that you have both your DRBD 8 userland binaries and kernel module ready to install. For our support customers, this means that you simply download two RPMs (or .debs) from our support web site. Make sure you have the right packages; you want those that match your system architecture and (for the kernel module) also your running kernel. Also, make sure you get …

Split brain, with DRBD, is much less of a disaster than in conventional cluster setups employing shared storage. But, you ask, how can I protect my DRBD cluster against split brain in the first place? Here’s how.

Let’s briefly reiterate what split brain, in the DRBD sense, really means. DRBD split brain occurs when your nodes have lost their replication link due to network failure, and you make both nodes Primary after that.

When just the replication link dies, Heartbeat as the cluster manager will still be able to “see” the peer node via an alternate communication path (which you hopefully have configured, see this post). Thus, there is nothing that would keep Heartbeat from migrating resources to that DRBD-wise disconnected node if it so decides or is so instructed. That would cause precisely the DRBD split …