If you were to ask someone “what is the most popular open source hypervisor” chances are that the answer will be KVM. Indeed KVM (or Kernel-based Virtual Machine) has played a key role in the open source Linux based virtualization environment. However is it really a hypervisor? Moreover, can KVM by itself run virtual machines? We will delve more into such questions in this blog. We will also understand the relationship between KVM and QEMU (Quick EMUlator).
Like previous years, I want to continue the habit of sharing my goals around blogging and learning experiments. Clearly, this update for the first half of 2014 is already late. In addition, I did slip up on the important goals of 2013.
In the previous blog of this series we saw that using Linux bridge we can connect a virtual Ethernet port of a VM to the physical Ethernet port of the hypervisor server. Let us now focus a bit more on these virtual ports to see what happens behind the scenes to make virtual networking actually work.
Software defined networking (SDN) is the current wave sweeping the networking industry. And one of the key enablers of SDN is virtual networking. While SDN and virtual networking are in vogue these days, the support for virtual networking is not a recent development. And Linux bridge has been the pioneer in this regard.
Log statements help record the flow of an application’s execution. Hence they are an important part of software coding process. For the Java language the common Log API libraries are Java Util Logger (commonly known as JUL), Apache Log4J, SLF4J etc. While these libraries support many advanced capabilities, most developers only use a handful of features. For example, ability to send log messages to files and the ability change log levels dynamically etc.
In this blog I will compare JUL against SLF4J and focus on these above mentioned features. Many will argue that this is not a fair comparison since SFL4J is really a facade and supports JUL as well. To clarify, I will compare the SimpleLogger that is bundled with SLF4J against direct JUL usage.
One of the biggest differentiation for various social networks is their usability. Let us look at some real world examples of how usability of social commenting can be improved with a simple solution.
At the beginning of the year, I had set myself few goals related to my blogging and learning activities. This belated mid-year review of those goals already gives an indication of how I have performed against the goals I set for myself.