Designing Services and Method granularity
Cohesion
defines how methods are grouped into different services. The method within a service are cohesive if they perform similar activities with closely related data
Types of Cohesion
Functional Cohesion
methods in a service are grouped together because they perform different aspect of single task
Sequential cohesion
methods in a service a grouped because they are called during the same phase in a process
Communication cohesion
method in a service are grouped together because they accept the same data as parameter

method granularity
As a general rule design method that perform an entire transaction
As a general rule if you cannot respond to a request within 5 sec, you should divide the request into multiple method

Using REST
Unlike SOAP and most other web services implementations, Restful web services do not require the use of XML

Message and Data Contracts
whenever possible use data contract because it is simpler to define and provide more flexibility by allowing you to use different messaging technique. Choose a message contract only when you need to conform to existing standard, such as when you need to replace an existing SOAP web service or when you need to pass information in the header separate from the data itself

Using SOAP Headers
System related info like
custom login credential
user token, preferences, application or operating system identification and versions, TimeStamps should be communicated through SOAP headers as opposed to being put in the body of messages
Custom SOAP headers using Generic Classes( create an instance of generic System.ServiceModel.Channels.MessageHeader using the data you need to pass to the header and then adding it to the OperationContext.Current.OutgoingMessageHeaders collection on the client. On the server read the header by calling the generic OperationContext.Current.IncomimhMessageHeaders.GetHeader

Asynchronous: one way operation that does not return response immediately but can return a response using a callback. Client of asyncronous service are not immediately aware of error that might occur
Synchronous: A two-way request response operation. The client submits a request and waits until the service returns a response. Synchronous
services can return fault messages which behaves like exception
Message Exchange Pattern
Stateful
Stateless ( as general rule use stateless where possible)
Versioning
Following this versioning technique ; increment the version number only when an update might cause another application to fail, and have other applications always prefer the version they were compiled and tested in. Updates must provide both backward and forward compatibility (forward compatibly means application compiled with the updates will work on a computer without the update)

	Creado por javakidson hace casi 11 años

Apunte sobre 70518, creado por javakidson el 22/08/2013.