Munin graphing of MySQL

While there are many graphing tools out there and we’ve used Munin for a while now. The MySQL plugin for Munin had fallen out of date and the show engine innodb status output changed in 5.5 making some bits of the plugin simply not work any more. Also the show global status has some extra variables so […]

MySQL Connector/Arduino

Chuck Bell, one of my former colleague from MySQL AB, has created a connector for Arduino to MySQL. So this allows Arduino code to be a direct client of a MySQL or MariaDB server, with Ethernet and WiFi shields supported. With Arduino boards being used more and more, this can come in really handy – not […]

Tool of the Day: MOSH (Mobile Shell)

Today I nominate MOSH (Mobile Shell) from MIT in our “tool of the day” category. With people working remote, we sometimes encounter connectivity issues. But even when working from a stable connection, it’s sometimes just a pest when you close your laptop even though you hadn’t quite finished looking at something on that SSH connection… […]

Storage caching options in Linux 3.9 kernel

dm-cache is (albeit still classified “experimental”) is in the just released Linux 3.9 kernel. It deals with generic block devices and uses the device mapper framework. While there have been a few other similar tools flying around, since this one has been adopted into the kernel it looks like this will be the one that […]

SPDY protocol available in nginx 1.4

Nginx 1.4 can now do SPDY (draft 2). It’s hiding away in a separate file http://nginx.org/en/docs/http/ngx_http_spdy_module.html So what is SPDY? In a nutshell, it does multiplexing, prioritization and compression of HTTP/HTTPS requests over a single TCP/IP connection. It also enables the server to push data before requested. These enable a browser or web services client to […]

Web Logs and Statistics

I’ve previously covered how user perspective and that browser to web server latency is a dominate cause of web server performance issues. Assuming you’ve resolved those as best as you can how to you measure server performance at a per request level. Web servers allow you to put their processing time into the logs however its not there by default. […]

Optimising Web Servers

I was lucky enough to attend PyCon-AU recently and one talk in particular highlighted the process of web server optimisation. Graham Dumpleton’s add-in talk Web Server Bottlenecks And Performance Tuning available on YouTube (with the majority of PyCon-AU talks) The first big note at the beginning is that the majority of the delay in user’s perception of a […]

Jetpants: a toolkit for huge MySQL topologies

From a Tumblr engineering blog post: Tumblr is one of the largest users of MySQL on the web. At present, our data set consists of over 60 billion relational rows, adding up to 21 terabytes of unique relational data. Managing over 200 dedicated database servers can be a bit of a handful, so naturally we […]

MySQL Cluster on Raspberry Pi

Earlier this week, Andrew Morgan wrote a piece on running MySQL Cluster on Raspberry Pi. Since the term “Cluster” is hideously overloaded, I’ll note that we’re talking about the NDB cluster storage engine here, a very specific architecture originally acquired by MySQL AB from Ericsson (telco). Raspberry Pi is a new single-board computer based on […]

Green HDs and RAID Arrays

Some so-called “Green” harddisks don’t like being in a RAID array. These are primarily SATA drives, and they gain their green credentials by being able reduce their RPM when not in use, as well as other aggressive power management trickery. That’s all cool and in a way desirable – we want our hardware to use […]