Transaction Management

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Transaction Management Using .NET Serviced
Components and COM Services
Speaker ???, Doff Park Feel_at_NET Senior
Consultant ForAce, WebTime ???? MCSD, MCT, CTT
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Agenda

• Introduction to Transaction Management
• Overview of COM Services and the .NET Serviced
  Components
• Creating .NET Serviced Components
• QA

Transaction Management Using .NET Serviced
Components and COM Services
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Introduction to Transaction Management

• General Idea of Transactions
• An Example of Transaction
• Local Transactions
• Distributed Transactions
• .NET Enterprise Services Transactions

Transaction Management Using .NET Serviced
Components and COM Services
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Introduction to Transaction Management
General Idea of Transactions

• A transaction is a set of separate but
  interdependent changes that are made to some
  persistent data and that must be performed
  together as an atomic operation
• ACID Properties
• Atomicity
• Consistency
• Isolation
• Durability

Transaction Management Using .NET Serviced
Components and COM Services
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Introduction to Transaction Management
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An Example of Transactions
Normal Transfer
Abnormal Transfer
Transaction Management
Error
Debit
Credit
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Components and COM Services
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Introduction to Transaction Management
Local Transactions

• Multiple select, insert, update, and delete
  operations are composed into a single atomic
  operation
• Local Transactions can be created by using
• Transact-SQL
• ADO.NET

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Components and COM Services
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Introduction to Transaction Management
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Distributed Transactions

• Microsoft Distributed Transaction Coordinator
  (DTC)
• Manages connections to multiple databases
• Manages connections from multiple database
  clients
• Coordinates work into a single transaction

Server A
Database1
Connection
Server B
Database2
Connection
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Components and COM Services
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Introduction to Transaction Management
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.NET Enterprise Services Transactions

• COM checks three bit flags to control
  transaction outcome and component life time
• Per object context Consistent flag and done
  flag
• Per transaction Abort flag

Transaction Stream
Sub1
Root Client
Root
Sub2
Abort
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Components and COM Services
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Overview of COM Services and the .NET Serviced
Components

• COM Services
• COM Catalog
• COM Context
• COM Interception
• How the .NET Framework Integrates with COM
  Services
• How the .NET Serviced Components Works with COM

Transaction Management Using .NET Serviced
Components and COM Services
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Overview of COM Services and the .NET Serviced
Components
COM Services

• COM is the application infrastructure in a
  multi-user environment that compose of the
  services that enable many users to access the
  application and underlying data at the same time.
• COM Services
• Transactions
• Compensating Resource Managers
• Resource Management
• Just-in-Time(JIT) Activation
• Object Pooling
• Synchronization
• Security
• Loosely Coupled Events
• Queued Components

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Components and COM Services
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Overview of COM Services and the .NET Serviced
Components
COM Catalog

• All configuration data is kept in a database
• You use the catalog to determine run-time
  requirements when an object is activated
• The catalog can be accessed by the Component
  Services tool or administrative API

Catalog
Application Type Server Name
MyApp Component Name MyClass
Application MyApp
Class MyClass
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Components and COM Services
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Overview of COM Services and the .NET Serviced
Components
COM Context

• Context is a set of run-time requirements for a
  class
• The COM catalog stores run-time requirements as
  attributes, which are checked during activation
• Context properties flow with the method call,
  depending on configuration attributes

Process
Application
Context A
Context B
Attributes TransactionRequired SynchronizationS
upported
Attributes TransactionRequired SynchronizationR
equiresNew
Object A
Object B
Properties TransactionID1234 ActivityID5678
Properties TransactionID1234 ActivityID9012
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Components and COM Services
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Overview of COM Services and the .NET Serviced
Components
COM Interception

• Used to enforce context semantics
• Transparent to the caller and the called
• Activation interception and method-call
  interception

Client Process
Application
Context A
Context B
Synchronization Required
Synchronization Not Supported
Interception
Object A
Object B
Object C
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Components and COM Services
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Overview of COM Services and the .NET Serviced
Components
How the .NET Framework Integrates with COM
Services

• The System.EnterpriseServices namespace provides
  necessary programming types
• Activation and interception are handled
  automatically through ServicedComponent class

.NET Enterprise Services
Common Language Runtime
COM Services
COM and Win32
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Components and COM Services
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Overview of COM Services and the .NET Serviced
Components
How the .NET Serviced Components Works with COM
Computer
COM Application Process
Context A
Context B
Interception
Object A objX
Object X
Proxy
objX new X ()
.NET Enterprise Services
COM Catalog
CoCreateInstance
CreateInstance
COM Services
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Components and COM Services
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Creating .NET Serviced Components

• Hosting Components in Component Services
• Transaction Attribute
• Transaction Voting
• Using the AutoComplete Attribute
• Setting Assembly Attributes
• Registering Assembly
• Monitoring COM Applications
• Demo Creating and Using StateU Serviced Component

Transaction Management Using .NET Serviced
Components and COM Services
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Creating .NET Serviced Components
Hosting Components in Component Services

• Add a reference to System.EnterpriseServices in
  your assembly
• The System.EnterpriseServices namespace provides
• ContextUtil class
• ServicedComponent class
• Assembly, class, and method attributes
• All component classes that need to be hosted
  within a Component Services application must
  inherit ServicedComponent class

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Components and COM Services
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Creating .NET Serviced Components
Transaction Attribute

• Transaction attributes specifies how a class
  participates in transactions
• Imports System.EnterpriseServices
• ltTransaction(TransactionOption.Required)gt Public
  Class bizStateU
• Inherits ServicedComponent
• End Class
• Options
• Disabled, NotSupported, Required, RequiresNew,
  Supported

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Components and COM Services
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Creating .NET Serviced Components
Transaction Voting - 1

• ContextUtil class provides transaction voting
• Public Sub TransferClass()
• Try
• ContextUtil.SetComplete()
• Catch ex As Exception
• ContextUtil.SetAbort()
• Throw ex
• End Try
• End Sub

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Components and COM Services
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Creating .NET Serviced Components
Transaction Voting - 2

• Transaction Voting Options
• Transaction is terminated when Done bit of all
  Context objects in transaction have True value

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Components and COM Services
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Creating .NET Serviced Components
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Transaction Voting - 3
Transaction Stream
EnableCommit
SetComplete
Commit
CTrue DTrue
CTrue DFalse
SetComplete
Root Client
CTrue DTrue
SetComplete
CTrue DTrue
C Consistent Bit D Done Bit
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Components and COM Services
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Creating .NET Serviced Components
Using the AutoComplete Attribute

• AutoComplete attribute avoids using the SetAbort,
  SetComplete, and ContextUtil methods
• ltAutoComplete()gt Public Sub SetStateU(ByVal pSQL
  As String)
• Dim comStateU As New SqlCommand(pSQL,
  conStateU)
• comStateU.ExecuteNonQuery()
• ' not SetComplete or SetAbort is required
• End Sub

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Components and COM Services
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Creating .NET Serviced Components
Setting Assembly Attributes

• The information is stored in the AssemblyInfo.vb
  file
• ApplicationName
• Description
• ApplicationActivation
• AssemblyKeyFile
• Create key file using Strong Name Utility sn.exe
• sn.exe k StateU.snk
• ltAssembly ApplicationName("StateU")gt
• ltAssembly Description("State University Serviced
  Component")gt
• ltAssembly ApplicationActivation(ActivationOption.
  Server)gt
• ltAssembly AssemblyKeyFile("StateU.snk")gt

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Components and COM Services
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Creating .NET Serviced Components
Registering Assembly

• Manual Registration
• Using .NET Framework Services Installation
  Utility Regsvcs.exe to register and create
  Component Services application
• Regsvcs.exe StateU.dll
• Automatic Registration
• Application registered on first use by client
  Lazy Registration

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Components and COM Services
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Creating .NET Serviced Components
Monitoring COM Applications
Transaction Management Using .NET Serviced
Components and COM Services
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Creating .NET Serviced Components
Demo Creating and Using StateU Serviced
Component
Transaction Management Using .NET Serviced
Components and COM Services
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Please allow me to omit part of more details, as
it is too long to take up the subject in
full. For more information about COM Services,
go to Microsoft certified technical education
center and take the course below. 2557 Building
COM Applications Using Microsoft .NET
Enterprise Services
Transaction Management Using .NET Serviced
Components and COM Services
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QA
Biz doff_at_feelanet.com msn bpark_at_hanafos.com www.
feelanet.com www.forace.net www.wtime.net
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Components and COM Services
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Thanks for your patience!