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Oracle Workflow Developer's Guide
Release 2.6.3.5
Part Number B12161-02
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Glossary |
Systems
A system is a logically isolated software environment such as a host machine or database instance. You should define each system to or from which you will communicate events in the Event Manager.
When you define a system, you can specify whether it is associated with a master system from which you want it to receive Event Manager object definition updates.
Each system can expose one or more addressable points of communication, called agents. After you define your systems, you should define the agents within those systems that you will use to communicate business events. See: Agents.
Local System
When you install Oracle Workflow in a database, that database is automatically defined as a system in the Event Manager and set as the local system in the Workflow Configuration page. The following table lists the default properties of the local system definition.
| Name
| <database global name>
|
| Display Name
| <database global name>
|
| Description
| Local System Created by Oracle Workflow Configuration Assistant
|
| Master
| (blank)
|
You can update the local system definition if necessary.
Oracle Workflow sets the status of the local system to Enabled by default. After you finish setting up the Business Event System, you can use the Workflow Configuration page to set the system status that you want for event processing. See: Setting Global User Preferences, Oracle Workflow Administrator's Guide.
Registering External Systems
Before you can send business events from one system to another, you must register the destination system with the source system as a potential recipient of event messages. Registering a system means defining the destination system as well as its inbound agents in the Event Manager of the source system, so that event messages from the source system can be addressed to the destination agents. Registering a system is also known as signing up a system.
Usually, both systems should be registered with each other, so that each system can both send messages to and receive messages from the other system.
Oracle Workflow provides web pages to help automate external system registration between two systems that both have Oracle Workflow installed. For communication between a Workflow-enabled system and a non-Workflow system, you must perform manual steps to store the required destination system and agent information in the source system.
To register a destination system for receiving event messages from a source system, perform the following steps:
1. Retrieve the local system and inbound agent definitions, which together make up the system identifier information, from the destination system.
Note: The system identifier information includes only the definitions for the system itself and its individual inbound agents. The system identifier does not include agent group definitions.
- If Oracle Workflow is installed on the destination system, you can use the Local System Identifier page on the destination system to generate and save an XML document containing the system identifier information. See: To Retrieve Local System Identifier Information.
Note: If you do not have access to the Oracle Workflow installation on the destination system, ask the workflow administrator for that system to perform this step.
- If Oracle Workflow is not installed on the destination system, you will need to manually gather the information needed to create definitions for the system and its inbound agents.
2. Register the destination system identifier information in the Event Manager in the source system.
- If Oracle Workflow is installed on both the source system and the destination system, you can use the External System Registration web page on the source system to register the information by raising the System Signup event with the system identifier XML document from the destination system as the event data. When the System Signup event is raised on the source system, Oracle Workflow executes a predefined subscription that loads the system identifier information to the Event Manager in that system. See: To Register an External System.
Note: If you do not have access to the Oracle Workflow installation on the source system, ask the workflow administrator for that system to perform this step.
- If Oracle Workflow is not installed on the source system but is installed on the destination system, you must store the system and inbound agent information for the destination system in the source system according to that non-Workflow source system's requirements. You can optionally make use of the system identifier XML document generated by the Local System Identifier page on the destination system, but you must manually perform whatever steps are necessary to store that information in the non-Workflow source system.
Synchronizing Systems
Synchronizing systems means replicating all the Event Manager objects that are defined on the source system to the target system. You can use the Synchronize Event Systems event to synchronize two Workflow-enabled systems with each other.
To Synchronize Systems
2. On the source system, modify the predefined subscription to the Seed Event Group with the Local source type.
- Specify the inbound agent on the target system that you want to receive the event message, or specify a workflow process that sends the event message to the target system.
Note: If you want to send the event message to more than one target system, you can specify an agent group to receive the event message.
Note: If you do not have access to the Oracle Workflow installation on the source system, ask the workflow administrator for that system to perform this step.
3. On the target system, enable the predefined subscription to the Seed Event Group with the External source type.
Note: If you do not have access to the Oracle Workflow installation on the target system, ask the workflow administrator for that system to perform this step.
4. On the source system, raise the Synchronize Event Systems event (oracle.apps.wf.event.all.sync) using the Test Business Event page for the event. Enter a unique event key, but do not enter any event data. See: To Raise a Test Event.
Note: If you do not have access to the Oracle Workflow installation on the source system, ask the workflow administrator for that system to perform this step.
When the Synchronize Event Systems event is raised on the source system, it triggers the subscription to the Seed Event Group with the Local source type. The Event Manager generates the event message, which contains the definitions of all the Event Manager objects on the local system, including events, event groups, systems, agents, agent groups, and subscriptions. Then the event message is sent to the specified inbound agent on the target system, or to the specified workflow process that sends the event message to the target system.
When the Synchronize Event Systems event is received on the target system, it triggers the subscription to the Seed Event Group with the External source type. Oracle Workflow loads the object definitions from the event message into the Event Manager on the target system, creating new definitions or updating existing definitions as necessary.
Automatic Replication
After you enable the predefined subscriptions in steps 2 and 3, these subscriptions will also replicate any subsequent changes you make to Event Manager object definitions on the source system. Whenever you create, update, or delete events, event group members, systems, agents, agent group members, or subscriptions, Oracle Workflow raises the corresponding predefined events. These events trigger the Local subscription to the Seed Event Group on the source system, which sends the object definition data to the target system. The External subscription to the Seed Event Group on the target system receives the data and adds, updates, or deletes the object definition in the Event Manager there.
If you do not want to continue automatically replicating changes on the source system to the target system, you can either disable the subscriptions after you finish synchronizing the systems, or disable the predefined events corresponding to those changes.
Master/Copy Systems
If you choose, you can treat one system as a master system that replicates its own Event Manager object definitions to its associated copy systems, but does not accept any object definition changes from those systems. To set up master/copy replication, perform the steps to synchronize the target copy systems with the source master system, as usual. Then, to prevent object definitions from being sent from the copy systems, ensure that the Local subscription to the Seed Event Group on the copy systems is disabled. To prevent object definitions from being received into the master system, ensure that the External subscription to the Seed Event Group on the master system is disabled as well.
See Also
To View and Maintain Systems
To Create or Update a System
To Retrieve Local System Identifier Information
To Register an External System
Predefined Workflow Events
Synchronize Event Systems Event
Seed Event Group
To View and Maintain Event Subscriptions
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