Invoke Service Activity
Functional overview of DataPower Orchestration Policy Invoke Service Activity.Orchestration Policy ActivitiesUsing Orchestration Policy
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The "Invoke Service Activity" is the first activity you must configure in a DataPower Orchestration Policy. This activity allows you to specify the service you would like to call with the activity and configure message input and output variables.
The policy includes the following configuration options:
- Allows you to specify a unique name for the activity.
- The name should describe what function the activity is performing (e.g., auditing service, attaching process results, etc.).
- Allows you to perform a search for the service you would like to call with this activity.
- Enter a keyword or Service QName to target the service you would like call with this activity and click Search.
- If there is a match, the Service, Interface, and Operation of the "Results" section will populate. You can obtain a full QName for a specific service in Services > Service Overview > Service QName section.
- You can also perform a search in the Configure > Registry > Binding or Configure > Registry Interfaces sections to target the service you are interested in.
- Displays search results in a service dialog by populating Service, Interface, and Operation drop-down menus.
- The service dialog could include multiple search results.
- Select a Service, Interface, and desired Operation you want to call for a service.
In orchestration, every activity has an input and it's resolves go to an output variable. For example, when a virtual service gets called, the results (output) are stored in a message variable. The Invoke Service Activity "Message" section allows you to direct message results to input and output variables. Output can be directed to a default message variable or a user-defined message variable.
For Input Variable and Output Variable, click the radio button of the message approach you would like to use:
- Message - A predefined variable that stores the results of an input or output message. With this option, the input and output of an activity is the input of the next activity based on the activity sequence defined in your Orchestration Policy.
- User-Defined - A user defined variable that allows you to save the results in one activity and use it in another activity. For example, you could have a logging service call and would like to take the incoming message (i.e., Input Variable = Message), and call the Policy Manager web service log service. Instead of replacing your incoming virtual message with the "Message" that came into your virtual service, you may decide you want to replace the message. In this case you could select "User-Defined" in the "Output Variable" section and specify message replacement text in the text box.
Each Orchestration Policy must include an "Invoke Service Activity" that is designated as the back-end service. The back-end service indirectly supports the front-end services and usually is closer to the required resource or has the capability to communicate with the required resource. In a virtualized service call, there is the virtual service where the message comes in, and there's the message that gets sent out for the next top. The "Designate as Backend Service" option allows you to designate the back-end service.
The "Designate as Backend Service" option is enabled (checked) by default to accommodate scenarios where only one "Invoke Service Activity" is configured in the Orchestration Policy. If the Orchestration Policy includes multiple instances of the "Invoke Service Activity," only one instance can have this option enabled.
- Designate as Backend Service - A checkbox that enables the current Invoke Service Activity as the back-end service. The Orchestration Policy enforces designating one "Invoke Service Activity" as a back-end service. If you attempt to save the Orchestration Policy without designating a back-end service, you will receive an error message.