Technology

Network in Hyper-scale data centers – Facebook

Sriram S
This is a guest post by Suryanarayana M N V. Having led teams working on Networking protocols, Surya has in-depth knowledge of networking. He has keen interest in the areas of Network Virtualization and NFV. A hyper-scale data center has tens of thousands of servers. How would the network be in such data centers? It need to be simple, scalable and fully automated. In this blog, I will share some insights into the network for Altoona DC of Facebook.

Linux Network Namespace – WILT

In the next installment of “What I learnt today” or WILT, I briefly touch upon Network Namespace. I came across Namespace as part of my ongoing study of OpenStack networking. Namespaces are powerful constructs in Linux that allows you to create a copy of the TCP/IP network stack -all the way from the Ethernet interfaces (L2), routing tables etc.

Are the NFV products comparable to dedicated-hardware products?

Sriram S

This is a guest post by Suryanarayana M N V. Having led teams working on Networking protocols, Surya has in-depth knowledge of networking. He has keen interest in the areas of Network Virtualization and NFV.

The most common NFV product that I had come across is in security domain viz., firewalls. To get an idea on how good they are, I checked the Juniper, PaloAlto & Fortinet Virtual Firewall products.

Introduction to NFV

Sriram S
This is a guest post by Suryanarayana M N V. Having led teams working on Networking protocols, Surya has in-depth knowledge of networking. He has keen interest in the areas of Network Virtualization and NFV. One of the buzzwords in the networking industry is NFV. In a series of blogs, I plan to share my understanding of NFV, its benefits, some of the products and its relationship with SDN.

KVM and QEMU – do you know the connection?

Sriram S

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).

Linux Bridge and Virtual Networking

Sriram S

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.

Using SL4J and SimpleLogger with Servlets

Sriram S
We saw in my previous blog that SLF4J and SimpleLogger support the most critical logging requirements with ease. In this blog, we will see how to use SLF4J in a Servlets based application. The general practice is to initialize logging related objects and parameters at the startup of an application. In case of Servlets, any of the servlet in the Web Application can be invoked due to user action. So we need to use a different technique for initializing logging related objects.

Log API Comparison – Java Logger vs SLF4J

Sriram S

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.