Vector implements a concurrency model that scales naturally with incoming data volume as shown above. Each Vector source is responsible for defining the unit of concurrency and implementing it accordingly. This allows for a natural concurrency model that adapts to however Vector is being used, avoiding the need for tedious concurrency tuning and configuration.
Stateless function transforms
As covered in the topology model document, Vector's concurrency relies on stateless function transforms that can be inlined at the source level. Therefore, task transforms should be defined at the end of your topology to allow for maximum transform inlining.