Amazon Ads

Wednesday, May 25, 2011

OAuth - A Brief Introduction

Oauth is the rescue mechanism when you want to share some of your data with another site or software without sharing the credentials for accessing your data. For e.g. If you want to share your photos that are private on Picasa without sharing your Picasa credentials with a Photo Studio for printing, OAuth comes to your rescue.

OAuth allows this by handing out a token to the requesting site instead of sharing the login credentials itself.

The token itself can define access to which site for which specific resources and for a defined duration.

This requires implementation from the accessing site as well as the site having the resources to share with the accessing site along with the device being used for the access.

1. User logs in to the Resource Accessing site (Consumer) like a print studio’s site

2. User places an order for print of photos stored in another site (Service Provider Site).

3. The Consumer site redirects the user to the Service Provider site

4. At the 2nd site, the user signs into the account where the site questions if the user certainly wants to share the resources with the origin site. On agreeing, the service provider site creates a token with information on what resources can be accessed for how long and

5. Then the token is shared with the Consumer site

6. Based on the token provided, the Consumer site can access the resources from the Provider site.

So, in this whole process the user did not have to share the login credentials at any point of time with the consumer site. This is the biggest advantage of the OAuth mechanism and is widely used by all the major social networking sites currently.

This helps in reducing the problem of having sharing resources across sites without sharing the user credentials between them.

In the OAuth Parlance, the following jargon are equivalent:

1. User a.k.a. Resource Owner

2. Service Provider a.k.a Server

3. Consumer a.k.a Client

Monday, February 14, 2011

Developing Apps for iPhone and iPad

While both iPhone and iPad are from Apple and have the same underling OS and it is possible to run applications built for iPhone to be installed on iPad as well, porting iPhone apps to iPad is not a straight forward exercise.

In principle, the same app can run, however the user experience will not be great and will not meet the expectations of the use as the larger real estate on iPad will not be efficiently used.

Also, there are some fundamental differences between the two which have to be kept in mind while developing the applications:

Yes (2 for video conferencing in iPhone 4)
Screen Size
3.5 inch display
9.7 inch display
960 x 480
1024 x 768
only on Wi-Fi supported Models
No Gyroscope

Every app needs to consider the Screen size and Resolution as the major difference. However apps that include phone features, GPS or Camera features will have to be rewritten for iPad. 

Also, the lack of gyroscope in iPad makes it not so very suitable for gaming apps.

Monday, February 7, 2011

Telnet on Windows 7

By default, telnet is not enabled on Windows 7 due to insecure connection security concern.

In order to enable and install Telnet in Windows 7, the steps are easy, and similar to procedures to turn on and enable Telnet in Windows Vista:

* Open Control Panel.
* Go to Programs or Programs and Features.
* Click Turn Windows features on or off.
* In the “Windows Features” dialog box, select (tick) the Telnet Client check box.

* Click OK.
* After installation is done, Telnet can be used and called immediately.

Friday, January 21, 2011

Enterprise Architect Vs. Solution Architect

There are a lot of Architects and types of Architectures that are spoken about leading to a dilution in the meaning and the responsibilities of each.

After going through the TOGAF literature on Enterprise Architecture, I was able to clearly distinguish between the roles and responsibilities of an Enterprise Architect and Solution Architect based on the work they are supposed to be doing.

Keeping in mind that Enterprise Architecture is to draw a Roadmap to align IT to Business by assessing the current state and understanding its gap from the target state, and Enterprise Architect is one who is able to come up with the transitional architectures that lead to various IT projects typically (sometimes even business projects).   EA would define the solution context along with the high level transition architectures and hand over to the 'Solution Architect' with the details of the analysis.

After this, the EA is involved only in Governance Procedures to ensure that the Solution in the project is being implemented on the suggested solution building blocks and adhering to the initially defined Architectural principles.  

It is at the point just before the roll out of projects or at the beginning of a roll out that a solution architect takes over from an EA and starts detailing the solution with the help of data, infrastructure and application architects (if required based on SMEs required). An SA would be answerable to an EA on any deviations required, justifications for the same etc.

Does this ring the bell? Is this the way the industry works? Any thoughts?

TOGAF and Zachman

There are quite a few Enterprise Architecture Frameworks like TOGAF, Zachman, DODAF, FEAF and many more.

However, the most often talked about are TOGAF and Zachman in the IT communities that I have interacted with. So, I thought, I will share my thoughts on what are the major differences between the two.

They have somethings in common but are widely different in terms of their coverage.

TOGAF is a methodology that includes a EA Process (The ADM) as well as the taxonomy and the required templates and guidelines for an enterprise architecture practice.

However, Zachman only provides only a taxonomy (pretty exhaustive) and is completely silent on the process, guidelines and techniques.

To draw parallels between the two, TOGAF suggests an Architecture Content Framework consisting of a Content Meta Model - Zachman's taxonomy maps to this part of the TOGAF specification.

Hence it is often claimed that TOGAF can work in conjunction with any other EA model like the Zachman Framework - since the taxonomy could be derived from Zachman while the process could be that of TOGAF.

What is Enterprise Architecture?

Here is my take on trying to define Enterprise Architecture:

It is a methodology
that provides a process, guidelines and techniques that help in developing an 'Enterprise Landscape' consisting of its Business Processes, its IT applications, its Data and its supporting Infrastructure (including their geographical spread)
thus enabling the enterprise to optimize and manage complexity, respond quickly to changes and align itself to the enterprise's Strategic Goal and Objectives
with clear transitional steps from the current state to the desired state, in the least disruptive way possible.

TOGAF 9 - A Brief Introduction

In the next few articles, I will be sharing my thoughts on TOGAF 9 as I am discovering it…

TOGAF 9, at the very outset is an Enterprise Architecture Methodology and a Framework. What does it mean? In simple terms, it provides the process to be followed as well as the content taxonomy along with some suggested techniques. It leds itself to tailoring for an enterprise's  specific needs.
However, it also seems like a  methodology that is very inclined towards the "IT nature" of an enterprise. I will write a separate blog article on why I feel so, with references to the TOGAF methodology.

Through its famous ADM (Architecture Development Method), it tells the various phases of a typical enterprise architecture iteration (as this needs to be done in iterations to be able to cover all the functions / verticals in an enterprise). 

I will briefly touch upon the 6 main parts that constitute TOGAF completely:
  1. The Architecture Development Method (ADM)
  2. ADM Guidelines and Techniques
  3. The Enterprise Continuum
  4. Architecture Content Framework
  5. TOGAF Reference Models
  6. The Architecture Capability Framework

A few words about what each of these mean:

ADM – This is a major component of TOGAF and provides guidance to the Enterprise Architecture group on the possible architecture development phases with each phase being described with details such as an objective, approach, inputs, steps, outputs. This is executed iteratively.

ADM Guidelines and Techniques – provides a large number of guidelines and techniques on how to apply ADM.  Guidelines help to adapt the ADM.  Techniques support specific tasks in ADM.

These I found to be basic, useful starting points and extensible.

The Enterprise Continuum – provides a model for structuring a virtual repository and provides methods for classifying architecture and solution artifacts. 

It helps in categorizing based on industry standards, architectural patterns etc. While TOGAF 8 just provided this, TOGAF 9 provides the below mentioned Architecture Content Framework which is one way of realizing the Enterprise Continuum.

Architecture Content Framework – provides a detailed model or meta model of architectural work products including deliverables, artifacts and the Architecture building blocks. This is one realization of the Enterprise Continuum.

This is very useful for creating taxonomy of enterprise architecture artifacts generated throughout the lifecycle of architectural work. Any repository to be maintained in the enterprise can get a starting point here.
The common thread across TOGAF is that every single bit is almost customizable to the context of one’s enterprise. 

TOGAF Reference Models – This provides one integration / interoperability reference model called the III-RM (Integrated Information Infrastructure Reference Model) and the TRM (Technical Reference Model).  

In my opinion, probably something known well in the industry and probably a bit archaic!

The Architecture Capability Framework – These are certain guidelines and resources to help an architect set up the architecture practice in an organization. 

This would be useful especially in the beginning of an EA practice.

Benefits of Enterprise Architecture

Of late, I have been wondering a lot about what tangible benefits would any Enterprise Architecture initiative bring to the Enterprise.
Or put in another way, when would an enterprise be driven to set up an Enterprise Architecture practice?

Here are a few reasons for starting an EA project.
  1. Rationalize / consolidate a large number of IT assets (data, application and infrastructure) that seem to have outgrown reasonable manageability (Reduce the complexity of IT Systems)
  2. Create a road-map on how IT will meet the business strategy in the years to come. ( Through performing a gap analysis after understanding the current and the target architectures)
  3. To enable an enterprise to be "agile". 
    • For the IT systems to be able to meet the changing business demands in very short cycles
  4. To enable an impact on the various layers of the organization (Business process, applications, infrastructure) due to a change in the Business Strategy or vision. Note: this is not easy for a large enterprise
  5. To bring about Process Optimization which could lead to lot of IT-related optimizations
  6. To bring about standardization across the organizations various sub-organizations
  7. To ensure the enterprise is compliant to regulatory requirements in a standard way across the organization