iBose

The Non Departmental Subjects

Recently in the tweets of one of my friends (who is lucky to be a student in this bad times) I found that he is quite bored with subjects like economics,accounting etc. as a part of his tech degree curricula.Back in 1999 when I was a student I too had these subjects in final semester.To be very honest I rarely attended those classes and somehow did an exam oriented study to get a fair score.Back then we (my friends and I) found them boring too.Surprisingly, in some of the classes I attended I found that the teacher also expects it that way.One day the teacher was really surprised to see too many students in the classroom.... actually it was raining heavily outside.

Journey with Patterns - Layers (Part 2)

In my earlier post I had discussed about the context/problem/solution of the Layers pattern and it's multiple implementation scenarios.In this part we will focus on the steps we need to follow in order to implement this pattern and it's benefits and challenges.

Implementation Steps

• Define the abstraction criteria
  • First we need to determine the criteria based on which we will define the layers
• Define the levels of abstraction
  • Once the criteria for abstraction is determined we need to define the levels of abstraction.This is a very critical task as we need to find the right level of abstraction and each abstraction level will correspond to one layer.So here we are deciding how many layers we will have.
• Name the layers and assign tasks to them
  • Here we need to name the layers for better clarity throughout the design process.We also need to clearly identify what tasks each of the layers will perform.The individual layers should have high level of cohesion in terms of the tasks they perform.

Journey with Patterns - Layer (Part I)

What do we do first, when designing a large complex system?We try to break it into smaller manageable pieces i.e. we try to decompose the system.This is the context in which Layers architectural pattern comes into picture.While doing so normally we come across the following challenges:

• Each component or subsystem should have clearly defined responsibilities and similar responsibilities needs to be grouped together for better clarity and maintainability.
• The components should have clearly defined interfaces for communicating with their other counterparts.
• Each subsystem should be replaceable with minimum impact on the other parts of the system.

Oracle Acquires Sun

Just read the news.Oracle to buy Sun for $ 7.4 Billion or $ 5.6 Billion net of Sun's cash and debt.After the deal with IBM didn't worked out everyone was eager to know about who's the next.So the next came Larry Ellison and he seems to be the final one.As per Mr. Ellison

"The acquisition of Sun transforms the IT industry, combining best-in-class enterprise software and mission-critical computing systems,"

Read details of the news at Reuters:

http://www.reuters.com/article/companyNews/idUKTRE53J2HI20090420

On the other hand Reuters reports that Microsoft CEO Steve Ballmer is taken by sheer surprise with breaking of this news.He said

"I just learnt it ... I need to think about it. I am very surprised,"

In the days to come we will see how Oracle handles with different businesses of Sun.Sustains,Transforms or Destroys.Tech experts and journalists seemed to most worried about Sun's hardware business as it does not match with Oracles all existing line of business.Next subject of great worry is MySQL.This open source database has become increasingly popular overtime under the patronage of Sun.MySQL in that way clashes with Oracle's Oracle the core the database business.So will it be wise for them to continue to support an open source product which is a competitor to some extent of their own flagship product?

Let's see......

CAPTCHA and Latest Innovation

So what is CAPTCHA? CAPTCHA is derived from the word "capture" but also is a contrived acronym of "Completely Automated Public Turing test to tell Computer and Humans Apart" .This is normally used to differentiate between human users from software programs (robots) in today's web based systems like Emails,Forums,Wiki's,Blogs etc.The main objective is to prevent software robots spamming these respective web based systems with mal content.So when we try to register with a website or post comment in a blog we are asked to enter a series of characters (usually mix of alphabets and number) displayed in a distorted fashion.This distortion and noise is added to ensure that only human intelligence can properly read and understand it.

This text based scheme has two issues - a) language dependence and data entry.This needs to be culture aware for human users to understand it properly and then data needs to manually keyed into the system.Google has recently released a research paper which overcomes these problems of text based recognition.This CAPTCHA technique is based upon identification of upright orientation of images.

The major challenge involved in this task is to remove the set of images that

• Are easy for automated orientation detection systems to identify
• Hard for human beings to identify proper orientation

To know about how it is done checkout the paper:

http://www.richgossweiler.com/projects/rotcaptcha/rotcaptcha.pdf

Let's see when we will find this in the web pages we use as netizens.

This seems to be big step for the fight against SPAM.

Journey with Patterns - Prologue

During our sessions and discussions in KolkataNET I have noticed that many of our members are aware of the term "patterns" in context of software development .They know about patterns like Singleton,MVC etc. but they are not very much clear on the basic purpose of patterns,difference between architectural and design patterns,what are the available and mostly referred to pattern catalogs etc.One possible reason might be that they have used some of the techniques and patterns in their development projects but did not studied much on the subject.Many of them have the interest but not enough time to get into the details.Some might have not got the right sources of information.

Service Virtualization & Managed Services Engine

Service Virtualization has now become a much discussed about topic in the SOA arena.Recently I came across a paper by Aaron Skonnard of Pluralsight on this topic.A very concise and self explanatory paper obviously with a focus on Microsoft Platform based implementation.Inspired by that I thought of sharing my understandings too (though at very initial stage)

So what is virtualization?It is the mechanism of abstracting the underlying details of any computing resource like server,network,storage etc from it's user.For example,server virtualization hides the details like the physical identity of the server,number of CPU etc from the end user.Similar concept can be applied to the services as well where the service consumers will work with virtualized version of the service without even knowing where and how it is hosted and other implementation details.

Design By Contract & DevLabs Code Contract

DevLabs is an initiative from Microsoft to reach out broad developer audiences with prototypes of technology that will be incorporated into products later.This is a very good opportunity for developers to play around with upcoming product features and provide their feedback to Microsoft.Recently I came across the Design By Contract related libraries released at DevLabs.This is named as "Code Contracts" and this will be shipped as part of .NET Framework 4.0 which is currently in CTP stage.In this post I will be discussing about the Design By Contract in general rather than the features provided by this library.

Business Rules and Rule Engines

Last week I was doing some analysis on the Rule Engine products available in the market.I was trying to figure out what generic features, a Rule Engine should have and against those features I was planning to compare the available products.In this post I will discuss about the basics of business rules,business processes and rules engines.

Cloud Computing - Amazon EC2

In my last post on Cloud Computing I had discussed about the various terms related to Cloud Computing like SaaS,Utility Computing,PaaS etc.After having a bit clearer understanding of these terms I have now started taking look at the various product and services offerings available in the cloud.To start with I have chosen the following Infrastructure Services provided by Amazon.

• Amazon Elastic Compute Cloud (EC2)
• Amazon Simple DB
• Amazon Simple Storage Service (S3).

In this post I will discuss about the Amazon EC2.