Difference between wcf and azure appfabric service bus?

Question

What is the diffence between appfabric service bus and WCF?

Is service bus is an alternate for wcf on azure?

Does service bus provide all the functionality as wcf?

when to use service bus and when to use wcf in azure application?

Please help me....

Thanks in advance

Answer 1

The service bus doesn't provide services themselves - instead if provides connectivity to services - eg routing, scalability, security, etc.

So you will normally write your services in WCF, and can then optionally provide connectivity to those services using the bus.

This article provides a good intro to the service bus - http://msdn.microsoft.com/en-us/magazine/dd569756.aspx

Answer 2

You don't need to move away from WCF. However, imagine your application, sitting in Windows Azure, trying to access a WCF service in your data center (or hosted somewhere). And imagine that the data center has a firewall that blocks incoming connections. Service bus offers a way for you to make service calls to that service endpoint. Essentially, the two sides each connect to an AppFabric Service Bus endpoint. At that point, they have a connection where WCF calls can be made.

The bindings are similar to what you use today. If you're using netTcpBinding, for instance, you'd now use netTcpRelayBinding, as the calls are relayed through the service bus.

The Windows Azure Platform Training Kit has a very good introductory lab to walk you through the basics of Service Bus.

Answer 3

ServiceBus is a way to communicate asynchronously. Asynchronous communication implies it is good for multi-machine programming due to fault tolerance and it does not block.

WCF is a programming stack used to interface with various mediums (ie. Pipes, TCP, HTTP, ServiceBus).

They serve orthogonal purposes. You can use WCF without ServiceBus and ServiceBus without WCF.