Friday, January 14, 2011

WAN performance management, mission impossible? [part 2]

Application visibility

A sound approach is to start with an assessment of your IT infrastructure by building a baseline of your application flows crossing the corporate wide area network. This results in application visibility. In many cases this baseline discloses quickly where on the (highway) connection traffic is building up, when flows of traffic are congested, how often this occurs and ho

w sever the perceived performance pain is and if it’s an isolated event or a trend.

A baseline in essence is a “picture” of an hourly, daily, weekly and monthly busi

ness period showing the utilization of IT infrastructure. The performance data must be actionable data, i.e. data that enables the company to make decisions upon.

An example of actionable data in layman’s terms is shown in the picture here. Detailed insi

ght into the application data that flows across the available data connections between corporate offices.

Shown here is that the data connection is used for various types of corporate user

s, applications and services. It also shows that at

several instances the

connection was claimed for 100% by a file transfer application an

d later on by a disk backup process (storage layer). This task also delayed other business applications in delivering data to and from the offices.

When measured with appropriate technology, the graphical output could be something like the graph shown here.

A so-called ‘brown-out’ on your infrastructure, a traffic jam, without any certainty of when it will resolve, resulting in end-user performance degradation, loss of good-will as IT department towards the business and loss of business opportunity and loss of revenues.

The baseline resulting in the application insight means also access to actionable performance information. Events like these, whereby uncontrolled application usage claims corporate resources at any given time, cannot be tolerated in any corporate infrastructure.

Results of such a baseline could already pin point to potential root causes of the problem, such as:

  • · Simply not enough bandwidth between the clients and application server

  • · So called “chattiness” of applications whereby many packets between client and server create a completed transaction.

  • · The distance between the client and server is so long that the data packets between the clientPC and the server simply take very long. This is called high latency.

[In part 3 I will review a number of senario's to resolve these issues using WAN Optimization and Acceleration techniques]