I presented a paper called Applying Innovative IT Modelling Methods to Low-level Grid Information for DSO Operations at the PowerTech Eindhoven 2015 conference. Distribution system operators will gather an increasing amount of electricity data from the lower level of the
Dynamically Scaling Apache Storm for the Analysis of Streaming Data
I presented a paper called Dynamically Scaling Apache Storm for the Analysis of Streaming Data at the 1st International Conference on Big Data Service (IEEE BigDataService 2015). Stream processing platforms allow applications to analyse incoming data continuously. Several use cases exist
Installing CoreOS on a XenServer VM
This guide can be used to install CoreOS on a XenServer VM. We will use PXE to boot a fresh VM, SSH into the box, run the install script, fix an issue with kexec not being available on XenServer, and
Fixing “Another operation involving the object is currently in progress” on XenServer
Sometimes XenServer does not allow you to shutdown or reboot a VM because “Another operation involving the object is currently in progress”. It would be nice to see what that operation is and be able to terminate the operation from
Sorting files alphabetically on FAT filesystems (USB disks, SD cards)
When using hardware devices to play music from SD cards or USB disks, you may find that they play files in non-alphabetical order. In my case, the Pioneer AVIC-F940BT device in my car showed and played MP3 files in almost
Fixing “unable to find partition containing kernel” on XenServer with Ubuntu VM
Sometimes an Ubuntu VM doesn’t start up anymore on XenServer. The following error is shown in XenCenter: Error: Starting VM ‘My VM’ – Using <class ‘grub.GrubConf.Grub2ConfigFile’> to parse /grub/grub.cfg – WARNING:root:Unknown directive load_video – WARNING:root:Unknown directive terminal_output – WARNING:root:Unknown directive
Storm in pictures
We’ve been using Storm for some time now. It is quite easy to start using it in a local environment (e.g. your IDE), but it can be a bit daunting to install a cluster and then really understand what Storm
Changing the number of columns in WordPress dashboard
The latest version of WordPress sets the number of columns in its dashboard to 4. This gives ugly results with some plugins that expect more horizontal room for their content, such as the Google Analytics plugin. Until the WordPress team
Getting metrics from the Java Virtual Machine (JVM)
Sometimes it is useful to see what the Java Virtual Machine (JVM) is doing when it is running your program. In this blog we will see how to get metrics about memory, buffers, threads and the garbage collection (gc) process
Creating a CentOS VM image for OpenStack
When you install OpenStack, you will get a very simple Linux VM image (Cirros) to test your installation. This works fine for testing purposes, but you will probably want to add some VM images for CentOS or Ubuntu. Although there