The Clientuses the “DomainDownload” Program to manage and monitor the download of a domain at the Server.

The basic state model for the DomainDownload Programis presented in Figure A.2. The Programhas three primary states, Ready, Running, and Halted which are aligned with the standard states of a ProgramStateMachineType. Additionally, the DomainDownloadTypeextends the ProgramStateMachineTypeby defining subordinate State Machinesfor the Program’sRunning and Halted states. The subordinate states describe the download operations in greater detail and allow the Clientto monitor the activity of the download at a finer resolution.

An instance (Program Invocation) of a DomainDownload Programis created by the Clienteach time a download is to be performed. The instance exists until explicitly removed by the Client. The initial state of the Programis Ready and the terminal state is Halted. The DomainDownload can be temporarily suspended and then resumed or aborted. Once halted, the program may not be restarted.

image011.png

Figure A.2– DomainDownload state diagram

The sequence of state transitions is illustrated in Figure A.2. Once the download is started, The Programprogresses to the Opening state. After the source of the data is opened, a sequence of transfers occurs in the Sending state. When the transfer completes the Objectsare closed in the Closing state. If the transfer is terminated before all of the data is downloaded or an error is encountered then the download is halted and the Programtransitions to the Aborted state; otherwise the Programhalts in the Completed state. The states are presented in Table A.1along with the state transitions.

The valid state transitions specified for the DomainDownload Program are specified inTable A.1.Each of the transitions defines a start state and end state for the transition and is identified by a unique number. Five of the transitions are from the base ProgramStateMachineTypeand retain the transition identifier numbers specified for Programs. The additional transitions relate the base Program states with the subordinate states defined for the DomainDownload. These states have been assigned unique transition identifier numbers that distinguish them from the base Programtransition identifiers. In cases where transitions occur between substates and the Program’sbase states, two transitions are specified. One transition identifies the base state change and a second sub-state change. For example, Ready to Running and to Opening occurs at the same time.

The table also specifies the defined states, causes for the transitions, and the effects of each transition. Program Control Methodsare used by the Clientto “run” the DomainDownload. The Methodscause or trigger the specified transitions. The transition effects are the specified EventTypeswhich notify the Clientof Programactivity.

Table A.1– DomainDownload states

No.

Transition name

Cause

From State

To State

Effect

2

ReadyToRunning

Start Method

Ready

Running

Report Transition 2 Event/Result

3

RunningToHalted

Halt Method/Error or Internal.

Running

Halted

Report Transition 3 Event/Result

5

RunningToSuspended

Suspend Method

Running

Suspended

Report Transition 5 Event/Result

6

SuspendedToRunning

Resume Method

Suspended

Running

Report Transition 6 Event/Result

7

SuspendedToHalted

Halt Method

Suspended

Halted

Report Transition 7 Event/Result

10

OpeningToSending

Internal

Opening

Sending

Report Transition 10 Event/Result

11

SendingToSending

Internal

Sending

Sending

Report Transition 11 Event/Result

12

SendingToClosing

Internal

Sending

Closing

Report Transition 12 Event/Result

13

SendingToAborted

Halt Method/Error

Opening

Aborted

Report Transition 13 Event/Result

14

ClosingToCompleted

Internal

Closing

Completed

Report Transition 14 Event/Result

15

SendingToSuspended

Suspend Method

Sending

Suspended

Report Transition 16 Event/Result

16

SuspendedToSending

Resume Method

Suspended

Sending

Report Transition 17 Event/Result

18

SuspendedToAborted

Halt Method

Suspended

Aborted

Report Transition 18 Event/Result

17

ToOpening

Internal

Ready

Opening

Report Transition 19 Event/Result

Four standard Program Methodsare specified for running the DomainDownload Program, Start, Suspend, Resume, and Halt. No additional Methods are specified. Thebase behaviours of these Methods are defined by theProgramStateMachineType. The Start Methodinitiates the download activity and passes the source and destination locations for the transfer. The Suspend Methodis used to pause the activity temporarily. The Resume Methodreinitiates the download, when paused. The Halt Methodaborts the download. Each of the Methods causes a Programstate transition and a sub state transition. The specific state transition depends on the current state at the time the Methodis called. If a Method Callis made when the DomainDownload is in a state for which that Method has no associated transition, the Methodreturns an error status indicating invalid state for the Method.

The Start Methodspecifies three input arguments to be passed when it is called: Domain Name, DomainSource, and DomainDestination. The other Methodsrequire no input arguments. No output arguments are specified for the DomainDownload Methods. The resultant error status for the Programis part of theCall Service.

A ProgramTransitionEventTypeis specified for each of the DomainDownload Programtransitions. The EventTypestrigger a specific Eventnotification to the Clientwhen the associated state transition occurs in the running ProgramInstance. The Eventnotification identifies the transition. The SendingToSending state transition also includes intermediate result data.

The SendingToSending Programtransition Eventrelays intermediate result data to the Clientalong with the notification. Each time the transition occurs, data items describing the amount and percentage of data transferred are sent to the Client.

The DomainDownload Programretains final result data following a completed or aborted download. The data includes the total transaction time and the size of the domain. In the event of an aborted download, the reason for the termination is retained.

The UA model for the DomainDownload Programis presented in the following tables and figures. Collectively they define the components that constitute this Program. For clarity, the figures present a progression of portions of the model that complement the contents of the tables and illustrate the Program’scomposition.

The type definition for the DomainDownload Programprecisely represents the behaviour of the Programin terms of UA components. These components can be browsed by a Clientto interpret or validate the actions of the Program.

The DomainDownloadType is a subtype derived from the ProgramStateMachineType. It specifies the use or non-use of optional ProgramStateMachineTypecomponents, valid extensions such as subordinate State Machines, and constrained attribute values applied to instances of DomainDownload Programs.

Table A.2specifies the optional and extended components defined by the DomainDownload Type. Note the references to two sub State Machine Types, TransferStateMachineand FinishStateMachine. The DomainDownloadType omits references to the Reset Program Control Methodand its associated state transition (HaltedToReady), which it does not support.

Table A.2– DomainDownloadType

Attribute

Value

Includes all non-optional attributes specified for the ProgramStateMachineType

BrowseName

DomainDownloadType

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

HasComponent

Object

TransferStateMachine

StateMachineType

Mandatory

HasComponent

Object

FinishStateMachine

StateMachineType

Mandatory

HasComponent

Variable

ProgramDiagnostic

ProgramDiagnostic2Type

Mandatory

HasComponent

Object

ReadyToRunning

TransitionType

--

HasComponent

Object

RunningToHalted

TransitionType

--

HasComponent

Object

RunningToSuspended

TransitionType

--

HasComponent

Object

SuspendedToRunning

TransitionType

--

HasComponent

Object

SuspendedToHalted

TransitionType

--

HasComponent

Method

Start

Mandatory

HasComponent

Method

Suspend

Mandatory

HasComponent

Method

Halt

Mandatory

HasComponent

Method

Resume

Mandatory

HasComponent

Object

FinalResultData

BaseObjectType

Mandatory

Table A.3specifies the Transfer State Machine typethat is a sub State Machineof the DomainDownload Program Type. This definition identifies the StateTypesthat compose the sub states for the Program’sRunning StateType.

Table A.3– TransferStateMachineType

Attribute

Value

Includes all attributes specified for the FiniteStateMachineType

BrowseName

TransferStateMachineType

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

HasComponent

Object

Opening

StateType

--

HasComponent

Object

Sending

StateType

--

HasComponent

Object

Closing

StateType

--

HasComponent

Object

ReadyToOpening

TransitionType

--

HasComponent

Object

OpeningToSending

TransitionType

--

HasComponent

Object

SendingToClosing

TransitionType

--

HasComponent

Object

SendingToAborted

TransitionType

--

HasComponent

Object

SendingToSuspended

TransitionType

--

HasComponent

Object

SuspendedToSending

TransitionType

--

HasComponent

Method

Start

Mandatory

HasComponent

Method

Suspend

Mandatory

HasComponent

Method

Halt

Mandatory

HasComponent

Method

Resume

Mandatory

Table A.3specifies the StateTypesassociated with the Transfer State Machine Type. All of these states are sub states of the Runningstate of the base ProgramStateMachineType.

The Opening state is the preparation state for the domain download.

The Sending state is the activity state for the transfer in which the data is moved from the source to destination.

The Closing state is the cleanup phase of the download.

Table A.4defines the states of the TransferStateMachineType.

Table A.4– Transfer State Machine – states

BrowseName

References

Target BrowseName

Value

Target TypeDefinition

NOTES

States

Opening

HasProperty

StateNumber

5

PropertyType

ToTransition

OpeningToSending

TransitionType

FromTransition

ToOpening

TransitionType

ToTransition

OpeningToSending

TransitionType

Sending

HasProperty

StateNumber

6

PropertyType

FromTransition

OpeningToSending

TransitionType

ToTransition

SendingToSending

TransitionType

ToTransition

SendingToClosing

TransitionType

ToTransition

SendingToSuspended

TransitionType

FromTransition

ToSending

TransitionType

Closing

HasProperty

StateNumber

7

PropertyType

ToTransition

ClosingToCompleted

TransitionType

ToTransition

ClosingToAborted

TransitionType

FromTransition

SendingToClosing

TransitionType

Table A.5specifies the Finish State Machine Typethat is a sub state machine of the DomainDownload ProgramStateMachineType. This definition identifies the StateTypesthat compose the sub states for the Program’sHalted StateType.

Table A.5– Finish State Machine Type

Attribute

Value

Includes all attributes specified for the FiniteStateMachineType

BrowseName

TransferStateMachineType

IsAbstract

False

References

NodeClass

BrowseName

Data

Type

TypeDefinition

Modelling

Rule

HasComponent

Object

Completed

StateType

--

HasComponent

Object

Aborted

StateType

--

Table A.6specifies the StateTypesassociated with the Finish State Machine Type. Note these are final states and that they have no associated transitions between them.

Table A.6– Finish State Machine – states

BrowseName

References

Target BrowseName

Value

Target TypeDefinition

NOTES

States

Aborted

HasProperty

StateNumber

8

PropertyType

FromTransition

OpeningToAborted

TransitionType

FromTransition

ClosingToAborted

TransitionType

Completed

HasProperty

StateNumber

9

PropertyType

FromTransition

ClosingToCompleted

TransitionType

The Aborted state is the terminal state that indicates an incomplete or failed domain download operation.

The Completed stateis the terminal state that indicates a successful domain download.

Table A.7specifies the constraining behaviour of a DomainDownload.

Table A.7– DomainDownloadType Property Attributes variable values

NodeClass

BrowseName

Data

Type

Data Value

Modelling

Rule

Variable

Creatable

Boolean

True

--

Variable

Deletable

Boolean

True

Mandatory

Variable

AutoDelete

Boolean

False

Mandatory

Variable

RecycleCount

Int32

0

Mandatory

Variable

InstanceCount

UInt32

PropertyType

--

Variable

MaxInstanceCount

UInt32

500

--

Variable

MaxRecycleCount

UInt32

0

--

A DomainDownload Program Invocationcan be created and also destroyed by a Client. The Program Invocationwill not delete itself when halted, but will persist until explicitly removed by the Client. A DomainDownload Program Invocationcannot be reset to restart. The Serverwill support up to 500 concurrent DomainDownload Program Invocations.

Figure A.3presents a partial DomainDownloadType model that illustrates the association between the states and the DomainDownload, Transfer, and Finish State Machines. Note that the current state number for the sub state machines is only valid when the DomainDownload active base state references the sub state machine, Running for the Transfer current state and Halted for the Finish current state.

image012.png

Figure A.3– DomainDownloadType partial state model

Table A.8specifies the ProgramTransitionTypesthat are defined in addition to the ProgramTransitionTypes specified for Programs inTable 7. Thesetypesassociate the Transfer and Finish sub state machine states with the states of the base Program.

Table A.8– Additional DomainDownload transition types

BrowseName

References

Target BrowseName

Value

Target TypeDefinition

NOTES

Transitions

ToSending

HasProperty

TransitionNumber

10

PropertyType

ToState

Sending

StateType

FromState

Opening

StateType

HasCause

Start

Method

HasEffect

ProgramTransitionEventType

HasEffect

AuditProgramTransitionEventType

SendingToSending

HasProperty

TransitionNumber

11

PropertyType

ToState

Sending

StateType

FromState

Sending

StateType

HasEffect

ProgramTransitionEventType

SendingToClosing

HasProperty

TransitionNumber

12

PropertyType

ToState

Closing

StateType

FromState

Sending

StateType

HasEffect

ProgramTransitionEventType

SendingToAborted

HasProperty

TransitionNumber

13

PropertyType

ToState

Aborted

StateType

FromState

Sending

StateType

HasCause

Halt

Method

HasEffect

ProgramTransitionEventType

HasEffect

AuditProgramTransitionEventType

ClosingToCompleted

HasProperty

TransitionNumber

14

PropertyType

ToState

Completed

StateType

FromState

Closing

StateType

HasEffect

ProgramTransitionEventType

SendingToSuspended

HasProperty

TransitionNumber

15

PropertyType

ToState

Suspended

StateType

FromState

Sending

StateType

HasCause

Suspend

Method

HasEffect

ProgramTransitionEventType

HasEffect

AuditProgramTransitionEventType

SuspendedToSending

HasProperty

TransitionNumber

16

PropertyType

ToState

Sending

StateType

FromState

Suspended

StateType

HasCause

Resume

Method

HasEffect

ProgramTransitionEventType

HasEffect

AuditProgramTransitionEventType

SuspendedToAborted

HasProperty

TransitionNumber

18

PropertyType

ToState

Aborted

StateType

FromState

Suspended

StateType

HasCause

Halt

Method

HasEffect

ProgramTransitionEventType

HasEffect

AuditProgramTransitionEventType

ReadyToOpening

HasProperty

TransitionNumber

17

PropertyType

ToState

Opening

StateType

FromState

Ready

StateType

HasCause

Start

Method

HasEffect

ProgramTransitionEventType

HasEffect

AuditProgramTransitionEventType

Figure A.4through Figure A.10illustrate portions of the DomainDownloadType model. In each figure, the referenced tates, Methods, transitions, and EventTypesare identified for one or two state transitions.

image013.png

Figure A.4– Ready To Running model

Figure A.4illustrates the model for the ReadyToRunning Programtransition. The transition is caused by the Start Method. The Start Methodrequires three input arguments. The Method Callservice is used by the Clientto invoke the Start Method and pass the arguments. When successful, the Program Invocationenters the Running state and the subordinate Transfer Opening state. The Serverissues two Eventnotifications, ReadyToRunning (2), and ToOpening (19).

Table A.9– Start Method additions

Attribute

Value

BrowseName

Start

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

HasProperty

Variable

InputArguments

Argument[]

PropertyType

--

Table A.9specifies that the Start Methodfor the DomainDownloadTyperequires input arguments. Table A.10identifies the Start Argumentsrequired.

Table A.10– StartArguments

Name

Type

Value

Argument 1

structure

 name

String

SourcePath

 dataType

NodeId

StringNodeId

 valueRank

Int32

-1 (-1 = scalar)

 arrayDimensions

UInt32[]

null

 description

LocalizedText

The source specifier for the domain

Argument 2

structure

 Name

String

DestinationPath

 dataType

NodeId

StringNodeId

 valueRank

Int32

-1 (-1 = scalar)

 arrayDimensions

UInt32[]

null

 description

LocalizedText

The destination specifier for the domain

Argument 3

structure

 name

String

DomainName

 dataType

NodeId

StringNodeId

 arrayDimensions

UInt32[]

null

 valueRank

Int32

-1 (-1 = scalar)

 description

LocalizedText

The name of the domain

Figure A.5illustrates the model for the Opening To Sending and the Sending to Closing Programtransitions. As specified in the transition table, these state transitions require no Methodsto occur, but rather are driven by the internal actions of the Server. Eventsare generated for each state transition (10 to 12), when they occur.

image014.png

Figure A.5– Opening To Sending To Closing model

Notice that a state transition can initiate and terminate at the same state (Sending). In this case the transition serves a purpose. The ProgramTransitionEventTypeeffect referenced by the SendingToSending state transition has an IntermediateResultData Object Reference. The IntermediateResultData Objectserves to identify two Variableswhose values are obtained each time the state transition occurs. The values are sent to the Clientwith the Eventnotification. Table A.11defines the IntermediateResults ObjectTypeand Table A.13defines the Variablesof the ObjectType.

Table A.11– IntermediateResults Object

Attribute

Value

Includes all attributes specified for the ObjectType

BrowseName

IntermediateResults

IsAbstract

False

References

NodeClass

BrowseName

Data

Type

TypeDefinition

Modelling

Rule

HasComponent

Variable

AmountTransferred

Long

VariableType

Mandatory

HasComponent

Variable

PercentageTransferred

Long

VariableType

Mandatory

Table A.12– Intermediate result data Variables

Intermediate Result Variables

Type

Value

Variable 1

Structure

 Name

String

AmountTransferred

 dataType

NodeId

StringNodeId

 description

LocalizedText

Bytes of domain data transferred.

Variable 2

Structure

 Name

String

PercentageTransferred

 dataType

NodeId

StringNodeId

 description

LocalizedText

Percentage of domain data transferred.

The model for the Running To Suspended state transition is illustrated in Figure A.6. The cause for this transition is the Suspend Method.The Clientcan pause the download of domain data to the control. The transition from Running to Suspended invokes the Eventgeneration for TransitionEventTypes5 and 16. Note that there is no longer a valid current state for the Transfer State Machine.

image015.png

Figure A.6– Running To Suspended model

The model for the SuspendedToRunning state transition is illustrated in Figure A.7. The cause for this transition is the Resume Method.The Clientcan resume the download of domain data to the control. The transition from Suspended to Running generates the Eventfor TransitionEventTypes6 and 17. Now that the Running state is active, the Sending state of the Transfer State Machine is again specified for the CurrentStateNumber.

image016.png

Figure A.7– Suspended To Running model

The model for the Running To Halted state transition for an abnormal termination of the domain download is illustrated in Figure A.8. The cause for this transition is the Halt Method.The Clientcan terminate the download of domain data to the control. The transition from Running To Halted generates the Eventfor TransitionEventTypes3 and 15. The TransitionEventType15 indicates the transition from the Sending state as the Running State ends and then to the Aborted state as the Halted state is entered.

image017.png

Figure A.8– Running To Halted – Aborted model

Figure A.9illustrates the model for the Suspended To Halted state transition for an abnormal termination of the domain download. The cause for this transition is the Halt Method.The Clientcan terminate the download of domain data to the control while it is suspended. The transition from SuspendedToHalted invokes the Eventnotifiers for TransitionEventTypes7 and 18.

image018.png

Figure A.9– Suspended To Aborted model

The model for the Running To Completed state transition for a normal termination of the domain download is illustrated in Figure A.10. The cause for this transition is internal. The transition from Closing To Halted generates the Event for TransitionEventTypes3 and 14. The TransitionEventType14 indicates the transition from the Closing state as the Running state ends and then to the Completed state as the Halted state is entered.

The DomainDownloadType includes a component reference to a FInalResultData Object. This Objectreferences Variablesthat persists information about the domain download once it has completed. This data can be read by Clientswho are not subscribed to Eventnotifications. The result data is described in Table A.13.

Table A.13– FinalResultData

Attribute

Value

Includes all attributes specified for the ObjectType

BrowseName

FinalResultData

IsAbstract

False

References

NodeClass

BrowseName

Data

Type

TypeDefinition

Modelling

Rule

HasComponent

Variable

DownloadPerformance

Double

BaseDataVariableType

Mandatory

HasComponent

Variable

FailureDetails

String

BaseDataVariableType

Mandatory

The Domain Download net transfer data rate and detailed reason for aborted downloads is retained as final result data for each Program Invocation.

DownloadPerformanceprovides the data rate in seconds for domain data transferred.

FailureDetailsprovides a descriptive reason for an abort.

image019.png

Figure A.10– Running To Completed model

Figure A.11illustrates a normal sequence of service exchanges between a Clientand Serverthat would occur during the life cycle of a DomainDownloadType Program Invocation.

image020.png

Figure A.11– Sequence of operations

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