Tag: programming

Fixing MySQL group commit (part 2)

This is the second in a series of three articles about ideas for implementing full support for group commit in MariaDB. The first article discussed the background: group commit in MySQL does not work when the binary log is enabled. See also the third article. Internally, InnoDB (and hence XtraDB) do support group commit. The… Continue reading Fixing MySQL group commit (part 2)

Fixing MySQL group commit (part 1)

This is the first in a series of three articles about ideas for implementing full support for group commit in MariaDB (for the other parts see the second and third articles). Group commit is an important optimisation for databases that helps mitigate the latency of physically writing data to permanent storage. Group commit can have… Continue reading Fixing MySQL group commit (part 1)

Debugging memory leaks in plugins with Valgrind

I had an interesting IRC discussion the other day with Monty Taylor about what turned out to be a limitation in Valgrind with respect to debugging memory leaks in dynamically loaded plugins. Monty Taylor’s original problem was with Drizzle, but as it turns out, it is common to all of the MySQL-derived code bases. When… Continue reading Debugging memory leaks in plugins with Valgrind

Fixing a MariaDB package bug

One of the things that I am really happy about in MariaDB is that we have our releases available as apt (and yum for Centos) repositories. This is largely thanks to being able to build this on the OurDelta package build infrastructure (which again builds on things like the Debian packaging scripts for MySQL). Something… Continue reading Fixing a MariaDB package bug

Building MariaDB/MySQL with Buildbot and KVM

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… Continue reading Building MariaDB/MySQL with Buildbot and KVM

Valgrinding Drizzle

Like so many others, I got interested in the Drizzle project when it started. Some good ideas, lots of enthusiasm, and just pure GPL license, no “yes, we will take your work for free and sell proprietary licenses to it” SCA. I even started contributing some development, fixing a number of Valgrind-detected bugs in Drizzle.… Continue reading Valgrinding Drizzle

Learning Python

Among other things, these past few months I have been working on setting up Buildbot, including adding various enhancements and bug fixes that are needed to properly build and test the MariaDB and MySQL code base. Since Buildbot is written in Python, this means I have also had to learn Python. I am an old-time… Continue reading Learning Python

Garbage collection and memory leaks

So, with automatic Garbage Collection, memory leaks are a thing of the past, right? Well, not quite, of course. Automatic Garbage Collection, like most other automated programming techniques, necessarily needs to approximate (ie. guess), and while the guesses of garbage collectors are generally very good, they cannot magically predict the future. The classic way that… Continue reading Garbage collection and memory leaks

BIT-aligned storage

I have been working on a set of efficient C++ classes for storing N-bit (N<=64) values at arbitrary bit offsets into a buffer. Essentially a way to address memory bit-wise, rather than the usual byte-wise or word-wise. The classes support either fixed-sized bitfield storage (eg. say 27-bit values), or compressed values where small numbers are… Continue reading BIT-aligned storage