Catch Up With Microsoft Azure Cloud Service Platform !

Window azure platform is a Microsoft’s cloud computing strategic platform which provides the facility of building, hosting and scaling web application. All this can happen through Microsoft datacenters. Thus It is classified as platform as a service or on demand platform along with software as a service.

One interesting thing about Windows azure is that it can be hosted in non Microsoft datacenters also. This will give a lot of choices to the users to leverage the cloud service of other vendors like HP, Dell, eBay etc based on Windows azure. The beauty of azure is that it use existing Microsoft technologies – virtual servers,.Net framework,IIS,Worker processes,databases,queues etc and open standards like REST,SOAP etc which makes learning curve bit thin.

Cloud computing is technology which uses internet and central remote server to maintain the data and application.It allows user to access applications without installation and access their personal files at any computer with internet access.

Very simple examples would be gmail or yahoo email. You don’t need to install a software or server to use them correct? All you need is internet connection and you can start using it. So same as this Windows azure is basically a application platform in the cloud which provide the facility to build or host such applications.

The cloud provides the endless range of services and applications. As i said previously it used Microsoft datacenters to host and run the applications. Azure platform uses the windows azure cloud operating system which serves as runtime for applications.It provides the functionality as development,management and hosting of applications off premises.

There are basically three components of windows azure:

1. Computer

2. Storage

3. Fabric

Computer and Storage are self explanatory terms.About fabric , now computer and storage are parts of fabric i would say. Fabric as the name suggest, makes up the windows azure as network of interconnected nodes consisting of servers,high speed connections.In computer component as it provides the computing environment with basically two roles i.e. web role and worker role.

Azure stores blobs,tables and queues. Azure blobs are very loosely organized into containers and blocks and it may have associated metadata as well.Manage resources and application and services on those resources is managed by Windows azure fabric controller service.Some of the functionality by Windows azure fabric controller are scheduling, resource allocation, device management etc.

The API of windows azure are build on HTTP, XML and REST. Developers can use this APIs to build the applications by interacting with services provided by windows azure. It also gives the client side managed class library which encapsulate the functions of interacting with the services.

There are total five kind of services provided by windows azure which a developer can use to build a application on cloud. They are as follows:

1. Live services

2. SQL Azure/ SQL Services

3. AppFabric/ .Net services

4. Sharepoint services

5. Dynamic CRM services

Live services – access data from Microsoft’s live applications and others and allow synchronisation

.Net services – distributed infrastructure services

SQL services – data services in the cloud based on sql server

Sharepoint services – web portal technology with commonly needed features

Dynamic CRM services – client server application which supports extensively web service interfaces

The programming model is familiar to the developers who have worked on .Net framework. Azure have various software developer kits and tools using which the development can be done on Windows vista SP1 or Windows server 2008.

The Microsoft is always being good in providing sample code for every new launch and azure is not exception for this. You can refer sample code and go ahead with your implementation. competition, yes there are competitors like Amazon EC2,Google app engine,Force.com etc which provides application running on cloud. But no doubt , Microsoft is exceptionally good :-)

Unleashed – Winodws Communication Foundation 4.0

The .NET Framework 4 comes with some compelling new features and welcomed improvements in the area of Windows Communication Foundation (WCF).

These WCF enhancements focus primarily on simplifying the developer experience, enabling more communication scenarios, and providing rich integration with one of the good foundation called Windows Workflow Foundation (WF).
WCF in .NET 4 comes with a wide range of specific features. Let us look them at the broader level.

Simplified Configuration

To make WCF configuration as much as easy for developer, the .NET 4 releases comes with a new “default” configuration model that completely removes the need for any WCF configuration.

If you don’t provide any WCF configuration for a particular service, the WCF runtime will automatically configure your service with some standard endpoints and default binding and behavior configurations.

Isn’t it a cool feature which they offered?
Simplification of the WCF configuration section through support for default endpoints, binding and behavior configurations.

These changes make it possible to host configuration-free services, greatly simplifying the developer experience for the most common WCF scenarios.

Discovery

WS-Discovery is an OASIS specification that defines a SOAP-based protocol for dynamically discovering the location of service endpoints at run time.

WS-Discovery defines two primary modes of operation: ad hoc mode and managed mode. In ad hoc mode, clients probe for services by sending multicast messages.

With managed service discovery, you provide a discovery proxy on the network that “manages” the discoverable service endpoints.

WCF in .NET 4 provides a complete implementation of the WS-Discovery protocol, and it provides support for both the ad hoc and managed discovery modes.


Routing Service

WCF in .NET 4 comes with a new class called Routing Service, which provides a generic WCF routing implementation for use within your applications.

The Routing Service can handle routing messages over any WCF-supported protocol using a variety of different messaging patterns.
New framework support for a configurable routing service that you can use in your WCF solutions. Provides features for content-based routing, protocol bridging, and error handling.

REST Improvements


REST is Representational State Transfer. It is the architectural style of building web services.Here they have introduced two things:

1. Automatic help page that describes Restful services to consumers of the service.
2. Support for declarative caching.These features were first introduced by the WCF REST Starter Kit last year and are now making it into the official framework.

Enhances the WCF 3.5 Web programming model with some additional features that simplify REST service development.


Workflow Services

This is the feature which received most attention in .NET 4.0. Here in .net 4.0 they have provided many improvements in integration of WCF and WF.

Although this has been possible since .NET 3.5, .NET 4 has made huge strides in improving the developer experience and providing some of the needed features that were missing in .NET 3.5.For example .NET 4 comes with new-and-improved hosting infrastructure for workflow services.
It also provides a standard workflow control endpoint for managing workflow instances remotely.
Rich new framework support for integrating WCF with WF to implement declarative long-running workflow services. This new programming model gives you the best both frameworks have to offer (WCF & WF).

Architecture of Windows communication foundation

Architecture at glance
Here I am talking about the Architecture of WCF in brief.
Architecture of Windows Communication Foundation consists of five layers. These layers from top to down are:
· Application: In this level application is located.
· Contracts: This is the contract layer which is all about the contract between service and clients.In this layer service, data and message contracts and policies are present. In this level services describe themselves to clients.
· Runtime: Behaviors are located in this layer. It is basically used to load all the services.
· Messaging: Different types of channels as well as encoders are here. This layer enables communications channel for services and clients. That means you can define the communication channel for services over here.
· Host: This layer is where host services in different manners, but there are two common ways to host a service.
You can host a service in Internet Information Services (IIS) which is easier than the second approach and which you usually do for any other service. It starts and stops your services automatically.
The second approach is to create executable files (.EXE) for services and start and stop them manually by writing more codes.
This layering allows developers to work on Windows Communication Foundation with different skills because each layer needs different skills.

Programming Approaches
Windows Communication Foundation has simple and easy to write/understand codes. It has many APIs, but beside this only a small amount of these API's is common.
There are three programming approaches in Windows Communication Foundation:
· Imperative: You use programming codes in different languages to accomplish a task. That means you can use different Programming languages.
· Configuration Based: You use configuration files to do things.
· Declarative: You use attributes to declare something.
You can use all this approaches to build the complete application in WCF.
In general, you will declare contracts and behaviors using attributes, configure endpoints, security and some other settings in configuration files and will implement service methods logic in codes using different programming languages.

You can work with the two types of services here:
1) Typed services
2) Untyped services.
In typed services you pass normal objects and data types and/or get normal objects and data types, but in untyped services you pass and get messages to work directly with messages at a lower level.

Basics of Windows Communication Foundation

Windows Communication foundation is one of the four major features introduced in the Microsoft .Net 3.0 freamework.

Windows Communication Foundation (formerly code-named "Indigo") is a set of .NET technologies for building and running connected systems. It is a new breed of communications infrastructure built around the Web services architecture.
Let us see what all enhancements are made by Microsoft in this coming version:

Windows Communication Foundation has some important enhancements in comparison with preceding technologies.
· It merges all older separate technologies in one place and allows you to do things easier.
· It has rich communication capabilities.
· It comes with many powerful and ready to use enterprise features.
· It can be integrated with other technologies and has great interoperability.

Fundamental Concept

In Windows Communication Foundation your services can have communication with clients by sending and receiving messages.

Windows Communication Foundation consists of three main concepts:
· Services: Programs that respond to clients. They can send or receive messages.
· Clients: Programs that ask for a service. They can send or receive messages.
· Intermediaries: Programs that sit between services and clients. They can work as a firewall or can rout messages. In all cases neither services nor clients need to be aware of intermediaries.

Most of the time, developers deal with services and clients and do not need to work much with intermediaries.
Services and clients have communications by sending and receiving messages, but again most of the time you do not work directly with messages and Windows Communication Foundation does this for you.

Here you should learn that a service can have more than one client and each service can be a client of another service itself.

Each of these main concepts has important concepts in its core or beside it. Some other concepts that you will deal with frequently are Channels, Bindings, Contracts, Behaviors, Addresses and Endpoints.