The Kafka Consumer input plugin is an event-based plugin. This means that it does not run on an interval and it instead creates a connection to Kafka and listens for events that Kafka is sending to it.
One option you are currently setting is the offset. By using the oldest, you are going to be replaying older data each time you connect. That may or may not be what you want.
Neither of these are valid settings as far as I am aware:
input_interval = "1s"
output_interval = "1s"
