Stream consumer activity is used to consume the stream. Sometime there could be a possibility that some streams are not being consumed by another activity. In that case, the unconsumed stream can cause a problem. You can use Stream Consumer activity to consume stream that is not being consumed by another activity.
Follow the steps to use Stream Consumer activity:
In Web Process Designer, click Repository View icon. All the items in the Activities list are displayed.
Expand Target > StreamConsumer.
Drag the StreamConsumer activity to the Canvas area.