Well isn’t that interesting, hidden all the way at the end of the MySQL 5.4 information are two words that really peaked my interest: Replication Heartbeat. And it wasn’t even using caps or other highlighting in the original text. Reading through the feature list of 5.4, I’m very impressed. All necessary/useful stuff for the real world, no marketing or enterprise blah.

Of course we’ll have to explore it in detail to have more opinion. Proof is in production, not paper. As this is the first most of us have heard/seen of it, it’ll take time to explore. Someone who tried to install the tarball this morning got an assertion during the system table installation. That’s not the best first impression, but that might be a build issue. I’m really pretty excited about the lineup of actual useful features.

Update… ok so at …

MySQL HA: 1. Desirable – most of the time, 2. Needed – often enough, 3. Available – there are some good options out there. Typical solutions consist of: Heartbeat with DRBD on Linux. Although HB was introduced to Linux, it can be used on Solaris, FreeBSD and others without the DRBD but with other solutions. Sun Cluster, Veritas (commercial), MySQL Proxy (still in [...]

Wow, check out what just came out from Linbit: The DRBD Management Console. Written in Java (so it runs anywhere), completely open source (GPLv3), and allows you to manage DRBD and Heartbeat based clusters. You can install, configure, see your systems graphically, and a lot more. I’m interested to try the beta out, as soon as I get back to my lab (sitting in the airport now). If you know how to use DRBD/Heartbeat, and use it in production for your MySQL setup, it might be a good application to test out, and improve if need be.

From the screenshots, I’m surprised this isn’t a value added extra that Linbit would like to charge for. Kudos, Linbit, for keeping it GPLv3!

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Last Friday and Saturday I had the pleasure of presenting DRBD-based high availability at the 2008 Zarafa Summer Camp. What’s this Zarafa thing, you ask? Here’s a quick introduction.

Zarafa is a fully LAMP-based, drop-in replacement for Microsoft Exchange developed by a Delft, Netherlands-based company. Yes, that means that all those Windows desktop users out there can use their beloved Microsoft Outlook to connect to a full-fledged collaboration solution, including email, calendaring, contact management, a global address book, and task sharing. Using native MAPI. And the server components are 100% built on Linux, Apache, MySQL, and PHP. They even use an …

Here's my presentation I gave June 9, 2008, at the Twin Cities MySQL and PHP User Group about my highly available cluster using DRBD and Heartbeat.

I added a few slides and cleaned things up a bit. The presentation went well and we had a lot of good questions.

The MySQL and PHP User Group will be taking some time off over the summer. There will be another meetup mid-summer to come up with some ideas for future meetings.

Here's my presentation I gave June 9, 2008, at the Twin Cities MySQL and PHP User Group about my highly available cluster using DRBD and Heartbeat.

I added a few slides and cleaned things up a bit. The presentation went well and we had a lot of good questions.

The MySQL and PHP User Group will be taking some time off over the summer. There will be another meetup mid-summer to come up with some ideas for future meetings.

• Tom Hanlon of MySQL presents
• monitoring tool basics
  • SHOW FULL PROCESSLIST
  • SHOW GLOBAL STATUS
  • SHOW GLOBAL VARIABLES
• basic tools
  • mysqladmin is provided with the server
    • mysqladmin -i 10 extended status: will repeat the same command every 10 seconds. Pipe through grep "and smoke it" (bad pun, hah hah)
    • -r: show only changed values
  • MySQL Administrator
• cacti
  • rrdtool based network graphing tool
  • uses snmp
  • PHP apache and MySQL based solution
  • MySQL plugins, download and install
  • "poller" gathers data and populates the graphs
  • someone offers …

The day of tutorials started out with All Bases Covered: A Hands-on Introduction to High-availability MySQL and DRBD by Florian Haas and Philipp Reisner.

After a brief introduction to DRBD, they started discussing the configuration file. There were a couple settings that I had set incorrectly on my servers.

Since I have my two servers connected via a gigabit crossover cable, I had my synchronization rate set to 125MB. They recommended approximately 1/3 your network and disk I/O so that you're applications don't freeze up during synchronization. Their test system used 30MB so I'll give it a try too.

Another setting they had different was the activity log extents. All of the references I looked at said to set the al-extents …

After a month of intense public review by our community users and contributors, we have made the initial “official” release of the DRBD User’s Guide.

This does not only include helpful information about building, installing, and configuring DRBD, but also on DRBD integration with Xen and LVM, Heartbeat, and many other applications. MySQL users will find the example MySQL HA configurations for both Heartbeat R1 and Heartbeat CRM clusters particularly helpful.

The release announcement is here: http://lists.linbit.com/pipermail/drbd-user/2008-March/009071.html

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I’ve heard from the guys at MySQL that the configuration of Heartbeat communication paths in ha.cf seems to be confusing to some. So, here’s our best practice summary:

• Never configure fewer than two communication paths. And I mean, never. Never. If you do, that’s an accident (read: split brain) waiting to happen.
• On the device that you run your DRBD replication over, if it uses a direct back-to-back connection to the peer node (like it should), configure a bcast link. Simple and easy to configure, and since you’re not sharing that link with anything other than DRBD replication, those broadcast packets won’t harm or …