Author: knielsen

Dissecting the MySQL replication binlog events

For the replication project that I am currently working on in MariaDB, I wanted to understand exactly what information is needed to do full replication of all MySQL/MariaDB statements on the level of completeness that existing replication does. So I went through the code, and this is what I found. What I am after here… Continue reading Dissecting the MySQL replication binlog events

Fixing MySQL group commit (part 4 of 3)

(No three–part series is complete without a part 4, right?) Here is an analogy that describes well what group commit does. We have a bus driving back and forth transporting people from A to B (corresponding to fsync() “transporting” commits to durable storage on disk). The group commit optimisation is to have the bus pick… Continue reading Fixing MySQL group commit (part 4 of 3)

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

MariaDB talk at the OpenSourceDays 2010 conference

Earlier this month, I was at the OpenSourceDays 2010 conference, giving a talk on MariaDB (the slides from the talk are available). The talk went quite well I think (though I probably talked way too fast as I usually do; at least that means that I finished on time with plenty room for questions..) There… Continue reading MariaDB talk at the OpenSourceDays 2010 conference

RunVM, a tool for automated scripting inside virtual machines

In the Autumn, I wrote about some experiments I did using KVM and virtual machines to build and test MariaDB binary packages on a number of different platforms. In the period since then I added some polish and refinements, and the system is now running well for some time. We build and test packages for… Continue reading RunVM, a tool for automated scripting inside virtual machines