I recently helped to analyze a performance issue with one of our MySQL customers, which highlighted the need to be cautious when sizing the query cache, and to validate whether it works well with your workload. The customer was evaluating a new 2-socket, 8 core, X64 system running Solaris, as a replication slave in an environment consisting of older systems running Linux. When they introduced the new slave, they found that it was unable to keep up with its replication load during their peak periods, and it took hours to catch up once the traffic dropped. The older systems running Linux had no trouble keeping up, so the obvious assumption was that there was something wrong with the new system, with Solaris, or with ZFS. In reality, the issue turned out to be an over sized MySQL query cache, and once that was addressed on the new system, it performed as expected.

The query cache is an interesting component of MySQL. It caches result sets of …

As I referenced in my prior entry, I'm reviewing Sun's three major strategic imperatives, and our progress going in to next fiscal year. Our strategic imperatives, in order, are:

1. Technology Adoption
2. Commercial Innovation
3. Efficiently Connecting 1. and 2.

This entry focuses on the first, Technology Adoption. Adoption is a non-economic phenomena, no money is spent, only time - yet it has extreme financial consequences. Let me give you an example.

I was with a big customer of ours last year, and reading through my account briefing before the meeting, I knew we were doing well. An analysis of their download activity showed they were heavy users of Solaris and OpenSolaris, and they had a large internal community of MySQL users, as well. In the meeting, their CIO said "we love where Solaris is headed." I …

I’m taking the MySQL Certification exams soon, and while I’d love to take advantage of official training, the closest classes near me will be in Buenos Aires (just a few hundred kilometers and an estuary away) in over a month, and I hope to be done with the Developer exams by then.

So I’ll be documenting, under the MySQL category, anything I think is worthwhile and could be of use for someone in my position.

My plan, so far, is to follow the book (which I was fortunate enough to find in a local book store, otherwise I’d have to add a few more days of delay to account for the Amazon delivery wait, even with the most expensive method), and check the online manual for updates, since the book is from 2005 so it’s probably outdated on quite a few things.

DBT2, with over 40% conflicts, is an very challenging benchmark, especially for an MVCC based engine. And, as a result, it is not a test that an engine is automatically good at. InnoDB has been extensively optimized for DBT2, and it shows.

For the last few weeks I have had the opportunity to focus on PBXT DBT2 performance for the first time. I started with a memory bound DBT2 test and the current state of this work is illustrated below.

These results were achieved using MySQL 5.1.30 on an 8 core, 64-bit, Linux machine with an SSD drive and a 5 warehouse DBT2 database.

The dip off at 32 threads is left as an exercise for the reader :) Patches will be excepted!

So what were the major changes that lead to this improvement?

Don't Wait Too Long!

When I began the optimizations, PBXT …

InitMarketing has made its calendar of world-wide conferences and trade fairs related to Free and Open Source Software, IT and specific industries available to the public.

It currently includes 122 events in 17 countries taking place in 2009. 43 of them in Germany, 69 in USA. We use this calendar when planing events for our customers, thus we’ll regularly update it. Please let us know of any events which are not on our radar yet by commenting to my blog or commenting at the bottom of the events page.

I recently helped to analyze a performance issue with one of our MySQL customers, which highlighted the need to be cautious when sizing the query cache, and to validate whether it works well with your workload. The customer was evaluating a new 2-socket, 8 core, X64 system running Solaris, as a replication slave in an environment consisting of older systems running Linux. When they introduced the new slave, they found that it was unable to keep up with its replication load during their peak periods, and it took hours to catch up once the traffic dropped. The older systems running Linux had no trouble keeping up, so the obvious assumption was that there was something wrong with the new system, with Solaris, or with ZFS. In reality, the issue turned out to be an over sized MySQL query cache, and once that was addressed on the new system, it performed as expected.

The query cache is an interesting component of MySQL. It caches result sets of …

I recently helped to analyze a performance issue with one of our MySQL customers, which highlighted the need to be cautious when sizing the query cache, and to validate whether it works well with your workload. The customer was evaluating a new 2-socket, 8 core, X64 system running Solaris, as a replication slave in an environment consisting of older systems running Linux. When they introduced the new slave, they found that it was unable to keep up with its replication load during their peak periods, and it took hours to catch up once the traffic dropped. The older systems running Linux had no trouble keeping up, so the obvious assumption was that there was something wrong with the new system, with Solaris, or with ZFS. In reality, the issue turned out to be an over sized MySQL query cache, and once that was addressed on the new system, it performed as expected.

The query cache is an interesting component of MySQL. It caches result sets of …

Netlog, one of the fastest-growing Web communities in Europe, today announced that it has purchased a MySQL Enterprise(TM) Unlimited subscription from Sun Microsystems to help ensure its database infrastructure will scale to handle its 300-percent traffic increase last year.

It’s certain now that Peter Gulutzan will be at the MySQL User Conference, live on stage.

Details within a few days.

This is actually a MySQL-related post, but I like odd analogies - stuff that makes you laugh tends to be remembered better!

So to get back to the fork... it's stuck in your head and you have a serious headache.
You go to the doctor. Would you like the doctor to
A) prescribe something for the headache, or
B) identify that the fork might be causing the headache, and suggest that it be removed?
There may be other factors causing the headache, but leaving the fork there is probably a bad idea anyway, right?

When someone asks me questions like "what's the maximum number of columns MySQL can have in a table", a little alarmbell goes off in my head (better than a fork, eh!), and I try to explore the "why" - much to some people's annoyance... they just want "the answer". But I do this because it's one of those anti-patterns, indicative of other issues. There are indeed valid reasons to require lots of …