A client recently asked me to fix some Cacti graphs that had broken after upgrading the Cacti templates I wrote for MySQL. The symptoms were weird; I’m not sure I understand fully what happened, but some of the graphs were OK and some had only part of the data they were supposed to. Some graphs would have one data element as usual, and others would be nan (not a number).

After turning on the debug logs, I found that the script was returning the data correctly — it was not a script problem. But after Cacti got the data from the script, it wasn’t associating it correctly with the RRD archives. Here’s a log message:

10/14/2009 12:05:05 PM - CMDPHP: Poller[0] Host[11] DS[1270] CMD: /usr/bin/php -q
  /opt/cacti/scripts/ss_get_mysql_stats.php --host dbserver
  --items bj,bm --user --pass , output: bj:68 bm:64
10/14/2009 12:05:05 PM - CMDPHP: Poller[0] DEVEL: …

Here’s a quick flowchart for the different ways that Kontrollbase gathers and processes data.

In addition to the Spider engine, Kentoku SHIBA has also created the …

OpenSQL Camp Portland 2009 is coming up on the 14th and 15th of November. Eric Day (of the Drizzle project) is the lead organiser this time around.

I went to the first edition in Charlottesville VA last year which was organised by Baron Schwartz (Percona). It was a great event, like other unconferences but with specific focus on database technologies. Monty (MySQL), Brian (Drizzle), Richard (SQLite), Jim (Interbase/Firebird/Falcon), Bruce (PostgreSQL) were all these, as were various storage engine builders. Very interesting, and lots of informal fun. If you’re anywhere near, do go!

Even though noone from our gang is able to make it to this one, Open Query is sponsoring this event – for all the above reasons. It rocks and deserves every support.

At Days of Wonder we are huge fans of MySQL (and since about a year of the various Open Query, Percona, Google or other community patches), up to the point we’re using MySQL for about everything in production.

But since we moved to 5.0, back 3 years ago our production databases which hold our website and online game systems has a unique issue: the mysqld process uses more and more RAM, up to the point where the kernel OOM decide to kill the process.

You’d certainly think we are complete morons because we didn’t do anything in the last 3 years to fix the issue

Unfortunately, I never couldn’t …

– Arjen Lentz, Exec.Director @ Open Query (http://openquery.com) Exceptional Services for MySQL at a fixed budget. Follow our blog at http://openquery.com/blog/ OurDelta: enhanced builds for MySQL @ http://ourdelta.org

Just a reminder – BarCamp Brisbane is on again this Saturday, all day, at the East Brisbane Bowls Club. Its a chance for techies and tech entrepreneurs to get together and meet each other, swap knowledge and ideas, and perhaps start new and exciting ventures. If you’re interested in coming along, please sign up and RSVP!

Open Query sponsors this event, together with lots of other locally-based businesses. From previous editions, I know it’s an excellent day, you always learn new things about unexpected topics!

For the my previous post, there was comment to suggest to test db_STRESS benchmark on XtraDB by Dimitri. And I tested and tuned for the benchmark. I will show you the tunings. It should be also tuning procedure for general heavy writing workloads.

At first, <tuning peak performance>. The next, <tuning purge operation> to stabilize performance  and to avoid decreasing performance.

<test condition>

Server:
PowerEdge R900, Four Quad Core E7320 Xeon, 2.13GHz, 32GB Memory, 16X2GB, 667MHz

db_STRESS:
32 sessions, RW=1, dbsize = 1000000, no thinktime

XtraDB: (mysql-5.1.39 + XtraDB-1.0.4-current)
innodb_io_capacity = 4000
innodb_support_xa = false
innodb_file_per_table = …

If you are SQL Server DBA interested in comparing "apples to apples" with MySQL... tomorrow's free webinar will be worth checking out. Windows/SQL Server vet Mike Frank and I will be running through the feature sets of both products and sorting out functional equivalents. (And yes, there will be some apples to oranges comparisons as well!) We'll be covering security, log shipping/replication, datatypes, partitioning and clustering just to name a few.

It's not too late to sign up for this and the rest of the "MySQL on Windows" webinar series, either...

Register for tomorrow's webinar here

View the upcoming webinars scheduled in the rest of the "MySQL on Windows" series …

A client recently asked me to fix some Cacti graphs that had broken after upgrading the Cacti templates I wrote for MySQL. The symptoms were weird; I’m not sure I understand fully what happened, but some of the graphs were OK and some had only part of the data they were supposed to. Some graphs would have one data element as usual, and others would be nan (not a number).

On the heels of our earlier announcement of Fernando and Yves, I'm happy to welcome Devananda van der Veen to our team.

Devananda, also known as Deva, is a talented, detail-oriented MySQL expert and systems administrator. His previous job was at Hydra, an advertising network, where he was sole DBA and half of the systems and network engineering team. Deva likes to automate: he wrote the mycat MySQL administration tools, and he knows how to administer lots of servers simultaneously. He is active in open-source software development, and very excited about Drizzle.

Deva lives with his wife and dogs on Washington's beautiful …