For years, Connector/Net has been a key part of any MySQL & .NET developer’s toolbox.  Tracing is also a key part of a developer’s life and Connector/Net has always output trace messages. 

This first post is a review of .NET tracing systems and how we changed our trace output.  The second post will cover how developers can use the new tracing format to develop new applications.

Tracing in .NET 1.x

.NET shipped with a very simple tracing system.  You have a static class named Trace that has static methods such as Write and WriteLine.  An application can use code like the following to output a message to the trace log. 

Now that we have output our message, how do we direct it somewhere?  You do that with listeners.  There are a few standard listeners included in the framework (ConsoleTraceListener, XmlTraceListener, EventLogTraceListener) but you are …

Optimizing Oracle Performance by Cary Millsap and Jeff Holt uses Oracle to make its points, but these points apply also to MySQL. The primary lesson I took away from this book is: all else aside, optimize/fix the user-action that provides the most economic benefit to the company; do this by profiling just that action and optimizing/fixing the most time-consuming events even if they are “idle” or “wait” events.

The authors call the aforementioned approach to performance optimization “Method R”. It’s meant to be deterministic and teachable unlike “Method C”–the conventional method–whereby one uses their best judgment and experience to find the cause(s) of problems and fix them. I agree, and Method R is fundamentally, imho, just the scientific method in practice. Therefore, I like Method R because it puts “science” back into “computer science.” …

If you have done a good job of building your rails models, you may find that they are helpful for your non-rails system maintenance and such. They may even be necessary to reuse if you follow the rails model of using activerecord validations (rather that database RI) to preserve the integrity of your data.

Or you may just find yourself rewriting the same code again and again, and want all that good railsiness to make it easier to write and maintain. Personally I find myself in some instance of ./script/console as often as irb just so I can get the activesupport helper methods ( 4.days.from_now and such) that many rails developers are surprised to find are not actually a standard part of ruby.

So, the good news is it is easy to reuse rails code outside of rails.

Let's say you want to do some data manipulation (reporting, loading, scrubbing, etc) in your rails db, …

In our last installment we found our hero investigating the tracing changes found in Connector/Net 6.2.  This time we’ll take a closer look at the format of the trace data and how developers can use that information to write new and interesting trace listeners.

Understanding the plumbing

The first thing we need to understand is a little about how the trace messages are routed.  The main method we are interested in is TraceSource.TraceEvent.  Here is the signature.

public void TraceEvent(
    TraceEventType eventType,
    int id,
    string format,
    params Object[] args)

All the other TraceSource methods like TraceInformation eventually boil down to a call to …

For years, Connector/Net has been a key part of any MySQL & .NET developer’s toolbox.  Tracing is also a key part of a developer’s life and Connector/Net has always output trace messages.

This first post is a review of .NET tracing systems and how we changed our trace output.  The second post will cover how developers can use the new tracing format to develop new applications.

Tracing in .NET 1.x

.NET shipped with a very simple tracing system.  You have a static class named Trace that has static methods such as Write and WriteLine.  An application can use code like the following to output a message to the trace log.

Now that we have output our message, how do we direct it somewhere?  You do that with listeners.  There are a few standard listeners included in the framework (ConsoleTraceListener, XmlTraceListener, EventLogTraceListener) but you are free to create …

Yesterday, I was working on a survey that Selena Deckelmann put together for open source databases. She will be presenting the results at Linux.conf.au this month.

One of the questions on the survey was this:

How would you describe your development process?

followed by these answer choices:

• Individuals request features
• Large/small group empowered to make decisions
• Benevolent dictator
• Other, please specify:____________

I thought a bit about the question and then answered the following in the “Other, please specify:” area:

Bit of a mix between all three above.

The more I think about it, the more I really do feel …

This walkthrough will show you how to configure your more or less clean install of Windows(you can use XP, Vista or 7) in order to build MySQL Cluster on Windows. The setup also works for the vanilla MySQL Server since the only real difference is the configure switches used to activate build of the NDB storage engine and the NDBCLUSTER handler.

Installing the necessary tools

• Install bison from GnuWin32 - http://gnuwin32.sourceforge.net/packages/bison.htm, this program is used generate the yacc parser in MySQL Server and is invoked automatically by a build rule. To avoid problem's with spaces in the path name, I recommend installing it to non default location c:\GnuWin32(i.e remove the "Program Files (x86)" part) - this is luckily the only tools that seem to have problem with spaces in the path.
  
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If you have done a good job of building your rails models, you may find that they are helpful for your non-rails system maintenance and such. They may even be necessary to reuse if you follow the rails model of using activerecord validations (rather that database RI) to preserve the integrity of your data.

Or you may just find yourself rewriting the same code again and again, and want all that good railsiness to make it easier to write and maintain. Personally I find myself in some instance of ./script/console as often as irb just so I can get the activesupport helper methods ( 4.days.from_now and such) that many rails developers are surprised to find are not actually a standard part of ruby.

So, the good news is it is easy to reuse rails code outside of rails.

Let’s say you want to do some data manipulation (reporting, loading, scrubbing, etc) in your rails db, and want to use your models to do it. A few imports …

Q4M 0.9 is now available from q4m.31tools.com, along with prebuilt binaries for MySQL 5.1.42 (running on linux and Mac OS X 10.5).

The release fixes a deadlock issue under high load.  Thank you to the users for sending the necessary information to resolve the issue.

If you still find any deadlocks or stability problems of Q4M, please send stacktraces of all threads (by attaching gdb to mysqld and executing "thread apply all bt").

Happy new year!

Just before Christmas the number of downloads of MONyog (from distinct email addresses) crossed 100,000. Here is the situation as of now:

This is of course a nice Christmas present for us to have. But more important: it reflects that today – as opposite to the situation just a few years ago – that even average MySQL users have understood that tuning the server configuration as well as the schemas and the queries used by applications is essential.

The default settings for the MySQL server are not appropriate for a heavy-loaded server and even the standard configuration files (or configuration ‘templates’) shipped with the server will not have the specific settings required for optimal configuration in most situations. And even the best server configuration won’t help much if databases and queries are poorly designed. We benefit from the growing understanding of this but also believe we have …