Process Group Ports: When You Need Them (and When You Don’t)

What ports do
Ports are required to move FlowFiles into or out of a process group.
If data crosses the group boundary, you must use input and/or output ports.

When you must use ports

• FlowFiles come from outside the process group

• FlowFiles need to leave the process group

• You’re connecting parent → child or child → parent groups

When you don’t need ports

• You’re using the process group purely for organization

• All FlowFiles stay inside the group

• You treat the group like a “function block” inside the parent

Most common confusion
You cannot draw connections across process group boundaries.
Use ports. That’s the rule.