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Tuesday, February 8, 2011

The place of WAN optimization in "d cloud"

In The IT industry, the word “Cloud” is a buzz word, and like all other computer industry buzzwords since the Inception of the X86 architecture, it has taken a myriad of meanings and coinages.

However, VMware, whose vSphere™ 4 is positioned as the industry’s first operating
system for building the internal cloud, uses this definition:

“Cloud computing is the use of networked infrastructure software and capacity to provide
resources to users in an on-demand environment. Sometimes known as utility computing,
clouds provide a set of typically virtualized computers which can provide users with the
ability to start and stop servers or use compute cycles only when needed, often paying only upon usage.”
This article is not meant for a freshman course in cloud computing(for that,you can read my other article here) but is meant to critically analyze the issues that trail the use of Cloud computing. Nonetheless, it is worthwhile to say that IT decision makers in organizations have taken to (or are considering being taken to) migrating their data and applications to “the cloud” due to the mouthwatering reduction in CAPEX (capital expenditure) and OPEX(Operating Expenditure) that it yields.
Enterprises don't shift overnight, and many C-level executives remain hesitant to adopt cloud too quickly or wholly. Commonly used to gauge the adoption of technology is Rogers' bell curve, which describes the acceptance of a new product or innovation over time. The model indicates that the first group of people to use a new product is called "innovators," followed by "early adopters." Next come the early and late majority, and the last group to eventually adopt a product are called "laggards."
According to Hitachi data systems, if the industry were to use Rogers' bell curve to examine the adoption of cloud computing, it might reveal that the early majority of the industry is waiting for early adopters to demonstrate the real value of cloud computing in business.  
 A viable reason why this is taking so much time to happen is possibly the fact that the cloud is largely dependent on the internet, needless to say… WAN AVAILABILITY.
The instinctive approach to this problem is for IT managers to get more bandwidth, but really how much bandwidth is enough? the truth is BANDWIDTH IS NEVER ENOUGH not to mention the cost implications of WAN upgrades.

Here comes WAN optimization to the rescue.  WAN optimization technologies working together to quickly and easily restore application performance, improve response time and recover WAN bandwidth, all without continuing the cycle of expensive WAN upgrades. These technologies include :

 The underlying protocol used to transfer files between clients and servers in an enterprise is known as CIFS(Common Internet File System). The protocol can be optimized by efficiently and transparently converting its serial nature of transfer into a parallel one. Also handshaking/chattiness is eliminated because parallelizing communications sends both request and acknowledgments all at the same time. This greatly reduces response times.


This works by observing repetitive content in client/server communications and application traffic, it then uses tokens that are lighter in weight to represent those data that are repetitive, significantly reducing file transfers.

Object caching stores re-usable application objects in a local cache so they can be immediately accessed by any user downstream from the appliance. This greatly reduces
bandwidth consumption and the latency(wait times between transfers) associated with file services. The only transactions that cross the WAN are a permissions and a freshness
check to ensure that the copy in the cache is still current.   

Due to the cost of bandwidth, it has to be efficiently constrained and managed. A good way of doing this is by application of business processes and policies .
Web developers in the head office in Victoria Island Lagos office must be given a guaranteed amount of bandwidth and top traffic priority to upload html files and css sheets of websites designed in the last week of each month to the “Cloud provider” in Port Harcourt.

Common industry compression algorithms used at wirespeed can further remove extraneous and predictable information from the traffic before it is transmitted. This
is especially helpful before byte and object caches have been fully populated.

Work is still being done in the industry to hardwire these techniques and better techniques into intelligent optimization appliances (Notably the Blue Coat proxySG appliance from Blue Coat Systems Inc.) to be plugged into the cloud infrastructure for optimized cloud performances.