Setting Input Adapter Properties

An input adapter is a program, usually running in the same JVM engine process as your EventFlow fragment, that converts data from an external source to the StreamBase tuple protocol. After adding an input adapter to an EventFlow canvas in StreamBase Studio, select or double-click its icon in the canvas to open its Properties view.

The Properties view for each adapter differs according to the capabilities offered by each adapter. The Properties view for input adapters always has a General tab, a Concurrency tab, and at least one Adapter Properties tab. Many adapters also have an Edit Schemas tab to specify the schema for tuples to be emitted output from the adapter.

Properties: General Tab

Name: Use this required field to specify or change the name of this instance of this component. The name must be unique within the current EventFlow module. The name can contain alphanumeric characters, underscores, and escaped special characters. Special characters can be escaped as described in Identifier Naming Rules. The first character must be alphabetic or an underscore.

Adapter: A read-only field that shows the formal name of the adapter.

Start with application: If this field is set to Yes (default) or to a module parameter that evaluates to true, this instance of this adapter starts as part of the JVM engine that runs this EventFlow fragment. If this field is set to No or to a module parameter that evaluates to false, the adapter instance is loaded with the engine, but does not start until you send an epadmin container resume command (or its sbadmin equivalent), or until you start the component with StreamBase Manager.

Enable Error Output Port: Select this checkbox to add an Error Port to this component. In the EventFlow canvas, the Error Port shows as a red output port, always the last port for the component. See Using Error Ports to learn about Error Ports.

Description: Optionally, enter text to briefly describe the purpose and function of the component. In the EventFlow Editor canvas, you can see the description by pressing Ctrl while the component's tooltip is displayed.

Properties: Adapter Properties Tabs

Use one or more adapter properties tabs to configure the unique properties for each adapter. Some adapters have a single tab in the Properties view named Adapter Properties. Other adapters have property settings spread out over multiple tabs.

Refer to the Properties section of each adapter's topic in the Adapters Guide to understand the property settings available for each adapter.

Properties: Edit Schema Tab

Use the Edit Schema tab to specify the schema of outgoing tuples from this input adapter. This functionality is similar to the Edit Schema tab for Input Streams, as described in Defining Input Streams.

Properties: Concurrency Tab

Use the Concurrency tab to specify parallel regions for this instance of this component, or multiplicity options, or both. The Concurrency tab settings are described in Concurrency Options, and dispatch styles are described in Dispatch Styles.

Caution

Concurrency settings are not suitable for every application, and using these settings requires a thorough analysis of your application. For details, see Execution Order and Concurrency, which includes important guidelines for using the concurrency options.