I've noted that one reason that InnoDB can get difficulties
when there are many concurrent transactions in the MySQL Server
is that the lock time of the kernel_mutex often increases
linearly with the number of active transactions. One such
example is in trx_assign_read_view where each transaction
that does a consistent read creates a copy of the transaction
list to be able to deduce the read view of the transaction or
statement.

This means that each transaction is copied to the local transaction
list while holding the critical kernel_mutex.

Another such case is that most operations will set some kind of
intention lock on the table. This lock code will walk through
all locks on the table to check for compatible locks and the
first time it will even do so twice. Thus if all threads use the
same table (as they do in e.g. sysbench) then the …

It is true that the summer vacation - lounging about, and getting a nice tan - is on its way, though we have chosen to do the opposite! By staying in doors and slapping on the sun cream we will be making our website lighter and brighter!

3 years after the big makeover (Gandi V1 to Gandi V2), we felt that it was time to brighten up our website. So that's what we did!

This version is not yet Gandi V3, it is more of a transitional stage, which has incorporated only subtle changes here and there - lightening up the graphics and making everything easier to read. Let’s call it Gandi V2.5!

As always, we welcome your comments, criticisms, reactions, large random shipments of candy…

As usual, click here to comment

Today, we are pleased to announce that we will be releasing .NL domain names. The official extension of the Netherlands is the 3rd largest country-specific extension in Europe (after .de and .co.uk), and the 4th largest in the world (with .cn in first place, with over 3 million active domain names).
It is available for registration to everyone at Gandi, because if you do not have a local contact for the administrative contact of the domain, we will automatically provide you with one for free.
See the .NL information page: https://www.gandi.net/domaine/nl/info

The extension is sold at €6 excl. vat for E rates, €12 excl. vat for A rates.
See the price list: https://www.gandi.net/domaine/prix/detail/nl/

Note that for .nl transfers, you need to accompany …

One of most loved feature of SQLyog is the snappy and responsive user interface. Many of our users and customers prefer SQLyog over other tools because of this particular reason.

One reason for the zippy interface could be that SQLyog is entirely developed in C/C++, which tends to be faster than other languages when it comes to raw speed. I don’t want to start a flame war here, but our customers seem to like this fact. Using C/C++ allows us to use the native MySQL C client libraries that gives the best performance as compared to other ways of communicating with MySQL. Using C/C++ also ensures that there are no external dependencies on any bulky frameworks and the download file is relatively small.

Although using a language that complies directly to machine instructions helps a lot, but true speed comes from better algorithms. A similar analogy in the MySQL context would be that you might get some benefits from tuning your …

There’s actually no single “correct” answer! It all depends on

1. where in a stack the component lives;
2. the state of the market for that component region;
3. sometimes even geographic location of the user comes into play.

Yes, for OSS projects modularity is handy in terms of handling contributions, but modularity may not be the best way to deal with a problem in a certain market state and situation!

Research has shown (see, for example, “The Innovator’s Solution” by Clayton Christensen) that the “integrated” region over time actually shifts to a subcomponent of an original integrated component that has since gone modular. An interesting example of this for MySQL its pluggable storage engine interface since version 5.1. MySQL is more modular now, but individual storage engines are tightly integrated for performance reasons, and in some cases they are even proprietary. …

Lately, there has been some talk about how users who do not feed code changes back into the open source codebase are "leeches " or "freeloaders ". This perspective demonstrates an incredible naiveté. Whether your customers never feedback a single line of code, they are adding tremendous value by the mere fact that they use your product. Let me explain.

First, what is more valuable: (1) a wonderful open source application used by 10 users who all provide code back to the community version; or (2) a closed source product with 200M users (think Microsoft Word)? Users are the most valuable asset a piece of software can have.

Much of this value is driven by the network effect . The more people who …

As some people have mentioned here and here Increasing the innodb log file size can lead to nice increases in performance. This is a trick we often deploy with clients so their is not anything really new here. However their is a caveat, please be aware their is a potentially huge downside to having large log file sizes and that’s crash recovery time. You trade real-world performance for crash recovery time. When your expecting your shiny Heartbeat-DRBD setup to fail-over in under a minute this can be disastrous! In fact I have been some places were recovery time is in the hours. Just keep this in mind before you change your settings.

By now everybody and their neigbour has realized that indeed Everything is a funky dns problem, Frank is giving talks about it at ZooCamp, and Serge figured out the hard way the downtime of planet.geekdinner.be was due to a dns problem :)

But I told you different things before ... and some of you listened others are still reinventing the wheel as we go ...

Matt A. points out that the OpenBravo folks realized that one should try to build on top of Open Source projects rather than modify core code ..

Wonder where he read that before : …

Update 8 June 2009
Be sure you to check out some of my research including Understanding your RAID Configuration and Understanding PERC RAID Controllers.

Last week I got caught thinking a MySQL production system wasn’t configured with RAID when it actually was. The following is the Linux dmesg output of 3 different client MySQL servers, where the H/W is all the same, a Dell 2950.

In the first two cases you will see individual references to the internal disks, however in the third you do not. This threw me, but as Matt Yonkovit correctly pointed out to me, the sizes are not standard drive sizes. …

Last week I posted the following twitter request — “Can somebody loan me (or buy me) a Dell 2950 decked out so I can run and publish some benchmarks. Please!”

In a same day response I was offered access to use 2 x Dell 1950’s, and today I’m now actually using these machines for my own testing. I would like to thank cafemom (Barry, Anthony & Dan) for the loan of hardware.

And now the chance to better understand the RAID configuration of the DELL PERC Controllers, trying out some different RAID types, LVM configurations and disk tests. When I’m done with my System Administrator refresher, I’m then be trying some different MySQL Benchmarks to test various MySQL configuration settings including using the new Juice …