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Drawing a Deployment Diagram


In order to build a threaded executable, you must supply information about the threads of the application. For each thread, you must specify which SDL instance sets that should run inside it. Finally, you may want to partition your SDL system into several executable files.

This information is modeled using Deployment Diagrams. These are edited using the Deployment Editor. The Deployment Diagram provides a way to model deployment of SDL systems independently of the target platform.

What You Will Learn

Starting the Deployment Editor

Deploying an SDL System

The Deployment Diagram features:

A deployment diagram has five symbols: the node, the component, the thread, the object and the comment symbols. Each symbol is described in Table 1.

Table 1
Symbol Name Description

Node

A computational resource, i.e. a computer

Component

An executable file which contains SDL instance sets

Thread

A point of execution. The symbol is used for threaded integrations only

Object

An SDL instance set, i.e. a system, block or process instance set

Deployment Diagram Symbols

The symbols are connected using compositions. When a symbol is selected in a diagram, a handle is shown at its bottom. Click the handle to create a composition link. Click the symbol you wish to connect to.

The name of each symbol can be edited from the diagram area. Some of the symbols contain additional information, which is edited from the Symbol Details dialog box.

The network_depl deployment diagram is shown in Figure 206.

Figure 206 : The network_depl Deployment Diagram

The diagram shows five components, each representing an executable file. All components are attached to one node. Each component has one or many threads. Each thread has one or many objects attached to it, reflecting the SDL instance sets that execute inside it.

For instance, the "JohnMS" component contains one thread, "T". The thread has one object attached to it, called "JohnMS". The object reflects an SDL instance set in the network SDL system. Look at the Organizer window and compare the block instance sets shown in the system with the objects in the deployment diagram.

The Symbol Details Dialog Box

The dialog box is opened in one of the following ways:

Component

Double-click the component named "John". The symbol details dialog box will appear. The dialog box is shown in Figure 207.

Figure 207 : The Symbol Details dialog box for Component "John"

The integration model can be selected from a drop-down list in the dialog box. The selected integration model controls the code generation parameters for the executable file that is generated from the component. Three integration models can be selected: Light, Threaded and Tight.

For the "John" component, the selected integration model is "Threaded". The information filled in the other text boxes is not used for code generation.

Thread

Click the thread symbol "T". The dialog box will change its content to reflect that of the thread. The new appearance of the dialog box is shown in Figure 208.

Figure 208 : The Symbol Details Dialog Box for Thread "T"

For a thread, four parameters can be set for performance-tuning of the generated executable:

The values of these parameters are specific to the target operating system. If no values are given, default values are used. All threads in the network_depl deployment diagram use default values.

Object

Click the object symbol "JohnMS". The dialog box will change its content to reflect that of the object. The new appearance of the dialog box is shown in Figure 209.

Figure 209 : The Symbol Details Dialog Box for Object "JohnMS"

For an object, two parameters are mandatory to fill in:

The stereotype is the type of SDL instance set. The possible values are "system", "block" and "process". "JohnMS" is a block, which is reflected in the stereotype text box.

The qualifier is used to identify the SDL instance set. Locate the "JohnMS" block in the Organizer window. The block instance set is located directly under the "network" system. This renders the qualifier "network/johnMS".

The network_depl diagram is complete. The next step is to build executable files from the diagram.

More information on the Deployment Editor is available in The Deployment Editor.


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