Wednesday, January 26, 2011

About Context reflux

Context reflux is the cost of context switching – moving from one cycle to another – in time , cpu cycles , or any other relevant unit .context reflux is sometimes is abbreviated as CR

Thursday, August 5, 2010

Clouds Clouds Clouds

This post is about a glimpse of various cloud technologies with the features and a bit about pricing.


1. Amazon Cloud

1 Cloud computing EC2
2 Content delivery Cloud front
3 Data storage Simple DB
Relation database service
4 Ecommerce Fulfillment service
5 Messaging Simple Queuing Service (SQS)
Simple Notification Service
6 Networking Virtual Private Cloud
Elastic Load balancing
7 Payments and billing Flexible Payment Service
Dev pay
8 Storage Simple Storage Service
Elastic Block Storage
9 Web traffic Alexa
10 Workforce Mechanical turk

No minimum Fees.
Pricing is based on the type of service used. Billing is done in the terms of usage per hour, data in/out.
Reserved instances carry a one time fee.
Pricing is different based on the base OS(windows machines carry higher charges)
Pricing differs region to region


2. Windows Azure Platform

1 Instance Windows Azure
2 Data Storage SQL Azure
3 Connecter App Fabric


Option of various packages depending upon the requirement (


3.Salesforce Platform

Provides a platform as a service.

1 Data storage S-Objects
2 Custom code Apex
3 UI Visualforce/ Point an click UI creation


Pricing is based on the edition of the salesforce. Cost is per month per edition


4. Google App Engine

Platform allows development of application on Python or Java. A hosted server is provided where th applications can be deployed. A free developer version is also available

1 Datastorage Big table (Provides Some JPA Features)
2 Custom code Java/Python
3 UI J2EE options (JSP , Freemarker etc)

Pricing is based on number of users. 8$ per user up to 1000$ max.

5. Heroku

Heroku is a ruby on rails based cloud.

1 DataStorage many DB supported
2 Coding Ruby on Rails

Pricing is based on following parameters  (

Database (storage)

Dynos (Http backend queue)

Workers (Background processes)


6. Wolf Frameworks

Provides a point and click for the UI creation.

Programming is based on C# and .Net  environment.  For database support there is a choice of MySQL and SQLServer.

Pricing ( is based on different packs like starter, standard, professional etc. Each pack has a limit on users, data storage, application , support etc.

Friday, June 25, 2010

What is cloud computing

This first post about benefits of creating your application online. I will explore the benefits and  the alternatives that are available.
Ok , lets see the definition of cloud computing .

"Cloud computing is defined as model of computing where the infrastructure , software resources and data are present outside."

Many points of vital importance are present in this definition which are explained below.
1. Model of computing : Cloud computing is diffrent from existing models of computing like mainframes and client server paradigms.

2. Infrastructure , software resources and data ; these three things are the building blocks of any software application.
  •    Infrastructure is the hardware required to host or run the application.
  •    Software resources are the building blocks of an application and constitute things like web servers ,   application installers , database etc.
  •   Data is well Anything of importance fed by user or computed by system .

3. Outside. This is the most important part of the definition. Outside implies the people using or developing the application are not responsible for the maintaince , upkeep of the key ingredients (Infrastructure , software resource and data). This is taken care by the people who are expert in this job. We just hire these key ingredients from them for a reasonable price.

Some where on internet I read that a proper anecdote to explain the cloud computing would be : "If you need milk , you dont need to buy the cow. You can buy milk from a store"

the cow here represents the three ingredients while the milk represents the application which we require.

So far so good.