Biztalk Pipeline Interview Preparation Guide

BizTalk Server provides a few out of the box pipeline components. For instance the S/MIME components for encrypting or decrypting messages. In case you need to do some pre or post processing on a message and the functionality is not offered through the provided pipeline components you will need to built your own custom pipeline component. The pipeline component(s) can then be used within a custom pipeline.

The receive pipeline consists of four stages
Decode Stage: This stage is used for components that decode or decrypt the message.
☛ Disassemble Stage: This stage is used for components that parse or disassemble the message.
☛ Validate Stage: This stage is used for components that validate the message format.
☛ Resolve Party Stage: This stage is a placeholder for the Party Resolution Pipeline Component.

Regarding to the send pipelines, they consist of three stages:
☛ Pre-assemble Stage: This stage is a placeholder for custom components that should perform some action on the message before the message is serialized.
☛ Assemble Stage: Components in this stage are responsible for assembling or serializing the message and converting it to or from XML.
☛ Encode Stage: This stage is used for components that encode or encrypt the message.

A runtime schema discovery will be attempted, Biztalk Server attempts to determine the correct flat file schema to assemble the message with, based on the namespace and the root node of the message.

☛ IBaseComponent,
☛ IComponentUI,
☛ IAssemblerComponent,
☛ IPersistPropertyBag

An XML schema defines the structure of a class of XML instance messages. Because this type of schema uses XML Schema definition (XSD) language to define the structure of an XML instance message, and this is the intended purpose of XSD, such schemas use XSD in a straightforward way.

A document schema is used to define a message. It is a definition on an Xml message with optional extensions for flat files, EDI file etc. that enable the parsers to convert the native format into Xml.
A property schema is used to define message context properties. These can be of type MessageDataPropertyBase (the property value is promoted or demoted from/to the message itself) or MessageContextPropertyBase(property value only exists within the message context and can be set by adapters, pipelines or within orchestrations).
If you wish to promote a field from a message into the message context then you need to define a document schema and property schema. In the document schema you promote the required field using the property schema to define the property type that will be used in the message context.

A send port is the combination of a send pipeline and a send adapter. A send port group is a collection of send ports and works much like an e-mail distribution list. A message sent to a send port group will be sent to all send ports in that group. The send pipeline is used to prepare a message coming from BizTalk Server for transmission to another service. The send adapter is responsible for actually sending the message using a specific protocol such as SOAP, or FTP.

Biztalk provides you with a really smart routing feature that allows the engine to decide where to send which message. For example, If you receive a message with the EmployeePaySlip schema, and it has the approved flag to true, it should be redirected to the Finance system Orchestration for making the payments and to the HR system Orchestration for keeping the records. This built in intelligence for the Biztalk engine allows it to route the messages simply based on some content within the messages.
In order to achieve this, the Biztalk engine obviously needs to understand the fields based on which the routing decisions can be taken. To simplify and optimize this working, Biztalk has introduced the notion of “promoted properties”. The Biztalk engine can get easy access to the promoted properties without knowing the entire message and hence it can save loads of time and complexity when dealing with routing. To route a message, the Biztalk engine simply reads its promoted properties and does not care about other contents in the message.

An envelope schema is a special type of XML schema. Envelope schemas are used to define the structure of XML envelopes, which are used to wrap one or more XML business documents into a single XML instance message. When you define an XML schema to be an envelope schema, a couple of additional property settings are required, depending on such factors as whether there is more than one root record defined in the envelope schema

A flat file schema defines the structure of a class of instance messages that use a flat file format, either delimited or positional or some combination thereof. Because the native semantic capabilities of XSD do not accommodate all of the requirements for defining the structure of flat file instance messages—such as the various types of delimiters that might be used for different records and fields within the flat file—BizTalk Server uses the annotation capabilities of XSD to store this extra information within an XSD schema. BizTalk Server defines a rich set of specific annotation tags that can be used to store all of the required additional information.