You can configure which Snaplex a Pipeline will use in the following ways:
With a Pipeline open in Designer, you can select from the Snaplex drop-down menu a Snaplex instance on which the Pipeline should run.
When you configure a Scheduled or Triggered Task, you can select the Snaplex to run the Pipeline.
The Pipeline Execute Snap has a Snaplex property that specifies where the child Pipeline is executed. When using a Pipeline Execute Snap, if you leave the property blank or use pipe.plexPath expression, the child Pipeline is executed on the same node as the parent. When running a parent and child Pipeline on the same node, data is not transferred over a network, which improves the performance of the Pipeline execution.
When using the Pipeline Execute Snap, if you specify a different Snaplex to run a child Pipeline, then the input documents and Pipeline parameters are passed (through the control plane using encrypted transport) to a node in the designated Snaplex.
To set a dedicated Snaplex for a project, an Org admin can move a Snaplex from the Shared project to any other project. Only those Pipelines within the new project have access to that Snaplex.