A few days ago I saw an article about Semi-Synchronous Replication in MySQL 5.5. It asks questions, and doesn't give answers beyond gut feeling. So I thought that I would do some practical testing of this new feature.
Before we go that way, though, let's revisit the theory.
How semi-synchronous replication works
Figure 1. A transaction with regular replication
With regular replication, you send a transaction to the master (1). When the COMMIT is received, the master executes it (2), and if successful it logs the transaction to the binary log (3). The the master answers the client request (4) with a successful result. In the meantime, the slaves replicate the record (5).
What happens if the master crashes after point #4 and before a slave has had a chance of getting the data in point #5?
…

I have old applications that need to read (and write) MyISAM tables that themselves receive lots of bulk updates. Time to try MySQL-Proxy.

MySQL Proxy is light on documentation and very few people written anything about working.   Most of what I have read says MySQL-Proxy is not ready for prim time.  I have hope so I had to give it a try.

I started with thee VMware servers. I setup one master and two read only slaves.   I tested the replication with mysqlslap from another independent server and it worked fine.  The slave never ran more then a second behind.

I downloaded mysql-proxy-0.8.0.tar.gz (64x version).  I …

To test my assumptions, I used one of my test Linux servers to perform a sysbench on 5.0.91, 5.1.47 built-in and plugin, and 5.5.4. The MySQL servers were all configured with

Let's start with the plugin. The documentation has been updated to cover this new feature. And 27 new tests give me some confidence that it …

Generally I avoid going down rabbit holes but today I decided to see how deep a particular testing rabbit hole went. This post is a third in what seems be a continuing series of programming anecdotes. It’s not particularly MySQL-related so you can stop reading here unless you grok code stuff.

Before beginning work on issue 720 I ran the mk-table-checksum test suite to make sure it was in working order. No sense writing new tests and code when the old tests and code aren’t reliable. I actually made one seemingly innocuous change to the test suite in preparation for the issue: I changed the –replicate checksum table from MyISAM to InnoDB.

Surprisingly, the test suite proved unstable. Random tests would fail at random times. Some instability was due to new tests for …

I’ve recently had the pleasure of reading “Python Testing: An easy and convenient approach to testing your python projects” from Packt Publishing. It’s been a quick read but a solid set of instructions on the different methods for the subject.

The book starts out very quickly with details about the various methods that are available, the means of automation for testing, and of course the environment you’d want to be in for working on the subjects that the book covers. It then, in the second chapter, moves into the guts of testing by describing the basics of doctest via syntax and some simple examples, and then moves on to a real world example via the AVL tree. It’s all very basic testing until chapter three where the author gets into unit testing, …

QA-Testing Definitions-Interview Questions: II (F – S): Data Dictionary: A database that contains definitions of all data items defined during analysis. Data Flow Diagram: A modeling notation that represents a functional decomposition of a system. Data Driven Testing: Testing in which the action of a test case is parameterized by externally defined data values, maintained […]

I have now published the Buildbot configuration file that we use for our continuous integration tests in our Buildbot setup. Every push into main and development branches of MariaDB is built and tested on a range of platforms to catch and fix any problems early (and we also test MySQL releases before merging to easily see whether any new problems already existed in MySQL or were introduced by something specific to MariaDB).

The configuration is included in the Tools for MariaDB Launchpad project.

Now, the Buildbot configuration file is not something that most …

Having produced a nice little series of 124 patches (yes, really), I recently had to find out what patch introduced a problem for distcheck to pass. Since distcheck takes quite some time to execute, I want to make as few runs as possible.

In Git, there is the bisect command that can be used to perform bisection testing of a series of patches, but quilt does not have anything like that, so to simplify my job, I needed to implement that for quilt.

I started by defining a shell function that did the actual test, and returned the result.

do_test () {
    echo -n "running distcheck..."
    make -j6 distcheck >/dev/null 2>&1
}

After that, I added code to add values for some variables used and to process options to the script. The script supports two options: --lower and …

Testing and automation. These two are key to ensuring high quality of software releases.

Ever since I worked briefly in the team at MySQL AB that is responsible for creating the binary (and source) packages of MySQL releases, I have had the vision of a fully automated release procedure. Whenever someone pushes a new commit to the release branch revision control tree, the continuous integration test framework should kick in and do all the steps needed for producing release packages:

• Checkout the new revision.
• Build a source tarball, and save it.
• For each platform, build a binary package from the source tarball. The build should be done in a freshly installed machine without any revision control checkouts, previous build trees, or extra installed software, to ensure that no unwanted dependencies or stray …