– 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 …

Hi,

We are pleased to announce MONyog 3.5 – a major new release. Listed below are the major features included in this release.

Error Log Monitoring

Monitoring the MySQL error log is absolutely critical for any MySQL DBA. Ignore the error log at your own peril! Many of our customers wanted an out-of-the-box solution for monitoring the error log. With the latest release, MONyog becomes the first MySQL Monitoring Tool to monitor the MySQL Error logs. MONyog can optionally send notifications over SMTP or SNMP for MySQL error log events that require attention.

As usual, none of the features of MONyog require you to install agents or additional software on hosts running MySQL.

SNMP Traps

We have introduced SNMP traps support in MONyog 3.5. SNMP traps …

Resolving extreme database overload for the customer recently I have found about 80 copies of same cron job running hammering the database. This number is rather extreme typically the affect is noticed and fixed well before that but the problem with run away cron jobs is way to frequent.

If slow down happens on the database server or job takes longer to run it often can't complete before its time for it to run again and unless prevented the second copy will run, which will have to compete with first copy for resources so having even less chance to finish. I leave the question of what effect on results running multiple cron jobs at the time may have.

Here are few practices which should help you to keep your cron jobs under control.

Prevent running multiple copies This is the most important one. I would suggest you having "production requirement" of no cron jobs allowed unless they prevent themselves from …

October, 8 I did master-class about catching error in SQL application at PHPConf 2009. Who speaks Russian can get slides here: pdf and odp.

There were several things which were interesting for me during my talk.

First is interaction with audience of different educational (or better to say MySQL practice) level. I should make a note for feature how to solve moments when 1/3 of audience listens carefully and is just right for the talk, another 1/3 knows things I am talking at the moment already and last 1/3 needs explanations of basic things such as what is difference between table-level and row-level locks. Probably I should create list of things user should …

So some 5 month later...
- Dbspj has an ndbapi
- Dbspj works enough for simple benchmarks!

Reminder, what is Dbspj:
- It's a new feature for Ndb
- It gives the possibility to push-down linked operations (e.g in SQL terminology: joins)
- It currently only supports left-outer-joins, and only some kinds of joins
- It is currently *not* in anyway integrated with mysqld (for accelerating SQL access)

Anyway so here is the benchmark setup
2 computers
- ndbapi running on one
- 2 datanodes running on other

On images below:
- red is new code, blue is corresponding "current" code
- Y-axis is run-time, so lower is better
- X-axis is "depth", i.e no of tables joined

Note: this is debug-compiled, so the actually absolute numbers are
not that interesting...rather the comparison...


Query 1: …

The GA binaries for MySQL Cluster 7.0.8a (the “a” is used to indicate that this is an increment on the original 7.0.8 source release) have been released – download them from http://dev.mysql.com/downloads/select.php?id=14

A summary of the changes can be found in the MySQL Cluster 7.0.8a Change Log