Adding a Persistent Subscribe Pattern

Set up persistent subscribe pattern (PSP) for any element in a project.

Create a PSP for a single subscriber. Start with an element such as a stream or window. When you enable PSP on the element, two additional shapes appear in the model: a control window (also known as a truncate window), and a Flex operator with a log store.

  1. Open the project in the Visual editor and choose the element that you would like to support PSP.
  2. (Optional) If an element suitable for PSP does not exist, create a new one:
    1. In the Visual editor Palette, click a shape tool such as Streams and Windows.
    2. Click the shape (element) you want to create (Input Stream, for example).
    3. Select a location in the diagram and click to add the shape.
  3. Right click the shape and select Modify>Add Persistent Subscribe Pattern.
  4. In the Select Store dialog, select either Create New Store or an existing store, then click OK.

    Studio creates two elements and attaches them to the shape you are configuring for PSP. The new elements are a Flex operator named <-PSP-shape-name>_log<number> and a truncate window named <-PSP-shape-name>_truncate<number>. The new truncate window and the shape you are configuring for PSP connect automatically to the new Flex operator.

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Parent topic: Guaranteed Delivery and Persistent Subscribe Pattern